conduit, it shall be contained in the conduit with the circuit

advertisement
conduit, i t shall be contained in the conduit with the circuit
conductors. Fittings and boxes shall be bonded or grounded in
accordance with Article 250.
SUBSTANTIATION: There is a very pressing need for an NEC
article to cover liquidtight flexible nonmetallic conduit for a
growing number of present day applications. Such a product is
being produced and has been used extensively in the machine tool
industry and other related uses for the past eleven years. At
the present time there is no NEC reference for this material.
I t may be agreed that the need for this article is such that
i t might be adopted based on the known, widespread and
successful use in industry of liquidtight flexible nonmetallic
conduit. Once in the NEC, such a product would immediately come
under the scrutiny of UL and would be required to meet the
levels of safety now required for other metallic and nonmetallic
raceways before being eligible for UL or equivalent listing and
for use wherever inspection under the NEC was required.
220-9 of NFPA#79 Electrical Standard for Met61working Machine
Tools covers liquidtight flexible nonmetallic conduit and
fittings.
E13.3.2 of EMP and EGP-I-1967 Joint Industrial Council
Electrical Standard covers Nonmetallic Conduit¢
Attached* is literature on this material:
(a) Anaconda Standard for Liquid Tight Flexible Nonmetallic
Electrical Conduit; latest revision 6/12/78.
(b) AnacondaBulletin S-550 (BED), pages $3 and $7.
*Attachments have been supplied to ~MP members.
PANEL RECOMMENDATION: Accept as Revised:
ARTICLE XXX - Liquidtight Flexible Nonmetallic Conduit
XXX-I. Scope. This article covers use and installation
requirements for liquidtight flexible nonmetallic conduit for
industrial application.
XXX-2. Definition. Liquidtight flexible nonmetallic conduit is
a raceway of circular cross sectioh having a smooth seamless
inner core and cover bonded together and having one or more
reinforcement layers between the core and cover. This conduit
is flame-resistant and with f i t t i n g s is approved for the
installation of electrical conductors.
XXX-3. Use.
(a) Liquidtight flexible nonmetal)ic conduit shall be
permitted to be used:
(1) i n exposed locations;
(2) where f l e x i b i l i t y is required for installation,
operation or maintenance;
(3) where protection of the contained conductors is
required from vapors, liquids or solids.
(b) Liquidtight flexible nonmetallic conduit shall not be
used:
(1) where subject to ohysical damage;
(2) where any combination of ambient and conductor
temperatures is In excess of that for which the liquidtight
flexible nonmetallic conduit is approved;
(3) in lengths longer than 6 feet;
Exception: where approved for special installations.
(4) where voltage of contained conductors is in excess of
600 volts, nominal.
XXX-4. Size. The sizes of liquidtight flexible nonmetallic
conduit shall be electrical trade sizes 1/2 inch to 1 1/2 inch
inclusive.
XXX-5. Nund}er of Conductors. The nuraber of conductors
permitted in a single conduit shall be in accordance with the
percentage f i l l specified in Table 1, Chapter 9.
XXX-6. Fittings. Liquidtight flexible nonmetallic conduit
shall be used only with terminal f i t t i n g s identified for such
use.
XXX-7. Grounding. Where a grounding conductor is required f o r
the circuits installed in liquidtight flexible nonmetallic
conduit, i t shall be contained in the conduit with the circuit
conductors. Fittings and boxes shall be bonded or grounded in
accordance with Arti.cle 250.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
8RETING: We believe the use of this material has been limited
for "connection to frequently moving parts" under the provisions
of Section 210-5(e) of NFPA Standard No. 79. This possible
additional use restriction needs further clarification.
351-9: Accept
C~ 8
SUBMII-FER: TSC-Approvedfor the Purpose
138 See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definltion of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "the purpose" and substitute "grounding."
VOTE ON PANELRECOF~4ENDATION: Unanimously Affirmative.
351-9, Exception: Accept
'
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
139 See the Technical Subcommittee "Recnmmendations"
un--n'de~-t'~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION/ See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~NIENDATION: Accept as Revised:
I Delete the words "the purpose° and substitute "grounding."
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
351-10: Accept
CMP 8
SUBMITTER: Dan Leaf, Westlake Village, CA
I)ITOIR~TAIZT.
• 140 Delete words "in concealed work" from the t i t l e ,
an--n'B-t'F~e-word "concealed" from the text.
SUBSTANTIATION: No restriction, per se, is placed on the
maximum number of bends in exposed work. No limit on number of
bends could result in de~nage to conductors, in a run with
excessive number of bends, or could encourage instaliatlon of
conductors prior to conduit installation, with conduit then
installed as a cable system. A limit on number of bends for
exposed work would bring this section in conformity with the
requirements for other raceway systems, such as 345-12, 346-11,
347-14, and 348-10.
PANEL RECOI~ENDATION: Accept as Revised:
Delete "For concealed raceway" after the words "A run of
conduit" and delete "in Concealed Work" from t i t l e .
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 352 -- SURFACERACEWAYS
352-I: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
]~l~b-O-S'~-~.• 141 See the Technical Subcommittee "Recummendations"
un--n-d'e-r-'t~e definition of "Approved for the Purposeu in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "unless approved for the purpose" and
substitute "unless otherwise approved."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
352-1: Reject
CMP 8
SUBMITTER: S. J. Casasant~, The Wiremold Co.
~ 1 4 2
Add the word "only" at the end .of the f i r s t
•~ .
Add new (1) as follows: (1) in damp locations;
unless approved for the purpose. Renumberremainder of
paragraph.
SUBSTANTIATION: The present wording is being interpreted as
permitting use of surface raceways in damp locations. The
addition of the word only in the above proposal clarifies that
surface raceways are i~tended for use in dry locations only,
unless approved for use in damp locations.
Panel 8 comment to Proposal No. 160, f o r the 1978 Code,
"Product not considered suitable for damp locations," is offered
as j u s t i f i c a t i o n for the above Woposal.
PANEL RECO)~(ENDATION: Reject.
PANEL C~ENT: No additional clarification would be achieved by
this Proposal.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 351 -- LIQUIDTIGHT FLEXIBLEMETAL CONDUIT
i
351-7: Accept
CMP 8
SUB)lITTER: TSC-Approvedfor the Purpose
137 See the Technical Subcommittee "Reco~ndations"
un--n-d'e'r-~'~e definition of "Approved for the Purpose'" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~ENDATION: Accept as Revised:
Delete the words "approved for the purpose" and add "approved"
!after the word "with."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-1: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
FR-O-~O
' -~-L-~: 143 In the f i r s t sentence, add the word "only" after
the word "permitted." In the second sentence (1), delete the
word "severe." In the second sentence (2), add the words "there.
are" after the word "where."
SUBSTANTIATION: The language is permissive and does not
restrict the use of surface raceways. See the attached opinion*
of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COIC¢~ENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECO@~IENDATION: UnanimouslyAffirmative.
154
conduit, i t shall be contained in the conduit with the circuit
conductors. Fittings and boxes shall be bonded or grounded in
accordance with Article 250.
SUBSTANTIATION: There is a very pressing need for an NEC
article to cover liquidtight flexible nonmetallic conduit for a
growing number of present day applications. Such a product is
being produced and has been used extensively in the machine tool
industry and other related uses for the past eleven years. At
the present time there is no NEC reference for this material.
I t may be agreed that the need for this article is such that
i t might be adopted based on the known, widespread and
successful use in industry of liquidtight flexible nonmetallic
conduit. Once in the NEC, such a product would immediately come
under the scrutiny of UL and would be required to meet the
levels of safety now required for other metallic and nonmetallic
raceways before being eligible for UL or equivalent listing and
for use wherever inspection under the NEC was required.
220-9 of NFPA#79 Electrical Standard for Met61working Machine
Tools covers liquidtight flexible nonmetallic conduit and
fittings.
E13.3.2 of EMP and EGP-I-1967 Joint Industrial Council
Electrical Standard covers Nonmetallic Conduit¢
Attached* is literature on this material:
(a) Anaconda Standard for Liquid Tight Flexible Nonmetallic
Electrical Conduit; latest revision 6/12/78.
(b) AnacondaBulletin S-550 (BED), pages $3 and $7.
*Attachments have been supplied to ~MP members.
PANEL RECOMMENDATION: Accept as Revised:
ARTICLE XXX - Liquidtight Flexible Nonmetallic Conduit
XXX-I. Scope. This article covers use and installation
requirements for liquidtight flexible nonmetallic conduit for
industrial application.
XXX-2. Definition. Liquidtight flexible nonmetallic conduit is
a raceway of circular cross sectioh having a smooth seamless
inner core and cover bonded together and having one or more
reinforcement layers between the core and cover. This conduit
is flame-resistant and with f i t t i n g s is approved for the
installation of electrical conductors.
XXX-3. Use.
(a) Liquidtight flexible nonmetal)ic conduit shall be
permitted to be used:
(1) i n exposed locations;
(2) where f l e x i b i l i t y is required for installation,
operation or maintenance;
(3) where protection of the contained conductors is
required from vapors, liquids or solids.
(b) Liquidtight flexible nonmetallic conduit shall not be
used:
(1) where subject to ohysical damage;
(2) where any combination of ambient and conductor
temperatures is In excess of that for which the liquidtight
flexible nonmetallic conduit is approved;
(3) in lengths longer than 6 feet;
Exception: where approved for special installations.
(4) where voltage of contained conductors is in excess of
600 volts, nominal.
XXX-4. Size. The sizes of liquidtight flexible nonmetallic
conduit shall be electrical trade sizes 1/2 inch to 1 1/2 inch
inclusive.
XXX-5. Nund}er of Conductors. The nuraber of conductors
permitted in a single conduit shall be in accordance with the
percentage f i l l specified in Table 1, Chapter 9.
XXX-6. Fittings. Liquidtight flexible nonmetallic conduit
shall be used only with terminal f i t t i n g s identified for such
use.
XXX-7. Grounding. Where a grounding conductor is required f o r
the circuits installed in liquidtight flexible nonmetallic
conduit, i t shall be contained in the conduit with the circuit
conductors. Fittings and boxes shall be bonded or grounded in
accordance with Arti.cle 250.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
8RETING: We believe the use of this material has been limited
for "connection to frequently moving parts" under the provisions
of Section 210-5(e) of NFPA Standard No. 79. This possible
additional use restriction needs further clarification.
351-9: Accept
C~ 8
SUBMII-FER: TSC-Approvedfor the Purpose
138 See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definltion of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "the purpose" and substitute "grounding."
VOTE ON PANELRECOF~4ENDATION: Unanimously Affirmative.
351-9, Exception: Accept
'
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
139 See the Technical Subcommittee "Recnmmendations"
un--n'de~-t'~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION/ See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~NIENDATION: Accept as Revised:
I Delete the words "the purpose° and substitute "grounding."
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
351-10: Accept
CMP 8
SUBMITTER: Dan Leaf, Westlake Village, CA
I)ITOIR~TAIZT.
• 140 Delete words "in concealed work" from the t i t l e ,
an--n'B-t'F~e-word "concealed" from the text.
SUBSTANTIATION: No restriction, per se, is placed on the
maximum number of bends in exposed work. No limit on number of
bends could result in de~nage to conductors, in a run with
excessive number of bends, or could encourage instaliatlon of
conductors prior to conduit installation, with conduit then
installed as a cable system. A limit on number of bends for
exposed work would bring this section in conformity with the
requirements for other raceway systems, such as 345-12, 346-11,
347-14, and 348-10.
PANEL RECOI~ENDATION: Accept as Revised:
Delete "For concealed raceway" after the words "A run of
conduit" and delete "in Concealed Work" from t i t l e .
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 352 -- SURFACERACEWAYS
352-I: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
]~l~b-O-S'~-~.• 141 See the Technical Subcommittee "Recummendations"
un--n-d'e-r-'t~e definition of "Approved for the Purposeu in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "unless approved for the purpose" and
substitute "unless otherwise approved."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
352-1: Reject
CMP 8
SUBMITTER: S. J. Casasant~, The Wiremold Co.
~ 1 4 2
Add the word "only" at the end .of the f i r s t
•~ .
Add new (1) as follows: (1) in damp locations;
unless approved for the purpose. Renumberremainder of
paragraph.
SUBSTANTIATION: The present wording is being interpreted as
permitting use of surface raceways in damp locations. The
addition of the word only in the above proposal clarifies that
surface raceways are i~tended for use in dry locations only,
unless approved for use in damp locations.
Panel 8 comment to Proposal No. 160, f o r the 1978 Code,
"Product not considered suitable for damp locations," is offered
as j u s t i f i c a t i o n for the above Woposal.
PANEL RECO)~(ENDATION: Reject.
PANEL C~ENT: No additional clarification would be achieved by
this Proposal.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 351 -- LIQUIDTIGHT FLEXIBLEMETAL CONDUIT
i
351-7: Accept
CMP 8
SUB)lITTER: TSC-Approvedfor the Purpose
137 See the Technical Subcommittee "Reco~ndations"
un--n-d'e'r-~'~e definition of "Approved for the Purpose'" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~ENDATION: Accept as Revised:
Delete the words "approved for the purpose" and add "approved"
!after the word "with."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-1: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
FR-O-~O
' -~-L-~: 143 In the f i r s t sentence, add the word "only" after
the word "permitted." In the second sentence (1), delete the
word "severe." In the second sentence (2), add the words "there.
are" after the word "where."
SUBSTANTIATION: The language is permissive and does not
restrict the use of surface raceways. See the attached opinion*
of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COIC¢~ENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECO@~IENDATION: UnanimouslyAffirmative.
154
352-1, Exception No. 1: Accept
CM°A 8
SUBMITTER: TSC-Approvedfor the Purpose
144 See the Technical Subcommittee "Recommendations"
un-"6Be'r--t-f~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~ENDATION: ~ccept as Revised:
Delete the words "approved for the purpose" and add at the end
of the exception: "where identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
restrict the use of underfloor raceways. See the attached
oplnion* of the San Diego City Attorney.
• *See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
P'Enel's Intent.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
354-15: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PKUPOSAL: 151 See the Technical Subcommittee "Recommendations"
un--n-d'e~-ElTe definitli)n of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
P.A.NEL RECOMMENDATION: Accept as Revised:
J Delete the words "approved for the purpose" and add "approved"
before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-8: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
145 See the Technical Subcommittee "Recommendations"
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
•"Delete the words "approved for the purpose for'which they are
used" and add the words "identified for such use."
VOTE ON PANELREC~NDATION: UnanimouslyAffirmative.
r
ARTICLE 356 -- CELLULAR METAL FLOORRACEWAYS
356-1: Reject
CMP 8
SUBMITTER: Charles T. Flachbarth, Walker Parkersburg Division
~ n c .
PROPOSAL: 152 Add a second sentence as follows:
"-"l~-6F'-Ehe purposes of this article, a cellular metal floor
consists of the entire floor area being covered with cellular
metal floor sections or a combination of cellular metal f l o o r
raceway sections and corrugated metal deck sections."
SUBSTANTIATION In somebuilding designs, there is confusion
'~egarding when a cellular metal floor raceway system as
described in Article 356 can be used, compared with an
underfloor raceway system as described in Article 354 can be
used. This proposed change will eliminate confusion regarding
when Article 356 applies or when Article 354 applies, without
changing the intention of the Code regarding the use of cellular
metal floor raceways or underfloor raceway systems.
PANEL RECOI~MENDATION: Reject.
FANEL COMMENT: No additional clarification would be achieved by
t h i s Proposal.
VOTE
ON PANELRECOMMENDATION:
i.
AFFIRMATIVE: 14.
'NEGATIVE: Breting.
EXPLANATION OF VOTE:
"'BREIIN6: Whlle Installation instructions are supplied by the
manufacturer covering the intended floor construction, this
proposal would provide clarification to those who may not have
access to these instructions.
352-22: Accept
OMP 8
SUBMITTER: TSC-Approvedfor the Purpose
146 See the Technical Subcommittee "Recommendations" '
uncler the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "flndlngs" under the definition of
"Approved .for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
Delete the words "unless approved for the purpose."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-22: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
PRUPUSAL: 147 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The .language is permissive and does not
restrict the use of nonmetallic surface raceways. See the
attached opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
llO-16(a).
PANEL RECO~g~ENDATION: Reject.
PANEL COMMENT:' The present wording adequately reflects the
Panel's Intent.
VOTE ON PANELRECO~iENDATION: UnanimouslyAffirmative.
356-11: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PITOFOSA
' L-T." 153 See the Technical Subcommittee "Recommendations"
un--n'de'r-~-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Arti~:le 100.
PANEL RECO~ENDATION: Accept as Revised:
....Delete the words "approved for the purpose" and add the word
"approved" before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 353 -- MULTIOUTLET ASSEMBLY
353-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
148 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The language is permissive and does not
restrict the use of multloutlet assemblies. See the attached
opinion* of the San Diego City Attorney.
,
*See Border County Div. IAEI substantiation for proposal for
110~16(a).
PANEL RECOMMENDATION: Reject.
PANEL CDMMENT:' The present wording adequately reflects the
Fanel's Intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
356-12-(New): Reject
CMP 8
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
154 Change the, present Section 356-12 to 356-13 and
~dd a new 356-12 (under Part A) as follows:
356-12. Aligning and Sealing. Cellular metal floor raceways
shall be so Installed that all sections which are used as
.
raceways for conductors are aligoed and joined to p~ovide a
smooth raceway free of sharp edges or foreign materials.
Raceway Joints shall be sealed to prevent the entrance of water
and concrete mix as soon as possible after the ducts are secured
in place.
SUBSTANTIATION: The ends of adjoining sections of cellular
metal floor raceways must be lined up to prevent insulation
damage during the wire pulling process.. The design of cellular
metal floor'does not assure alignment and there are no specific
Code requirements for such an alignment. Accordingly, this has
caused problems in enforcement. Also, the joints must be taped
or sealed to prevent the entrance of water or concrete which
obviously can damage the conductor insulation when branch
circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is prlmarily a design consideration.
V'dTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Young.
353-2: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
I~TOPI~L-~.. 149 See the Technical Subco~ittee "Recommendations"
un--6"d~-F-tT~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the wOrds "unless approved for the purpose.".
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
t
ARTICLE 354 -- UNDERFLOOR RACEWAYS
354-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAE'I
150 In the f i r s t sentence, add the word "only" after
"permitted." In the third sentence, delete the word
"severe."
SUBSTANTIATION: The language is permissive and does not
155
352-1, Exception No. 1: Accept
CM°A 8
SUBMITTER: TSC-Approvedfor the Purpose
144 See the Technical Subcommittee "Recommendations"
un-"6Be'r--t-f~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~ENDATION: ~ccept as Revised:
Delete the words "approved for the purpose" and add at the end
of the exception: "where identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
restrict the use of underfloor raceways. See the attached
oplnion* of the San Diego City Attorney.
• *See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
P'Enel's Intent.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
354-15: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PKUPOSAL: 151 See the Technical Subcommittee "Recommendations"
un--n-d'e~-ElTe definitli)n of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
P.A.NEL RECOMMENDATION: Accept as Revised:
J Delete the words "approved for the purpose" and add "approved"
before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-8: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
145 See the Technical Subcommittee "Recommendations"
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
•"Delete the words "approved for the purpose for'which they are
used" and add the words "identified for such use."
VOTE ON PANELREC~NDATION: UnanimouslyAffirmative.
r
ARTICLE 356 -- CELLULAR METAL FLOORRACEWAYS
356-1: Reject
CMP 8
SUBMITTER: Charles T. Flachbarth, Walker Parkersburg Division
~ n c .
PROPOSAL: 152 Add a second sentence as follows:
"-"l~-6F'-Ehe purposes of this article, a cellular metal floor
consists of the entire floor area being covered with cellular
metal floor sections or a combination of cellular metal f l o o r
raceway sections and corrugated metal deck sections."
SUBSTANTIATION In somebuilding designs, there is confusion
'~egarding when a cellular metal floor raceway system as
described in Article 356 can be used, compared with an
underfloor raceway system as described in Article 354 can be
used. This proposed change will eliminate confusion regarding
when Article 356 applies or when Article 354 applies, without
changing the intention of the Code regarding the use of cellular
metal floor raceways or underfloor raceway systems.
PANEL RECOI~MENDATION: Reject.
FANEL COMMENT: No additional clarification would be achieved by
t h i s Proposal.
VOTE
ON PANELRECOMMENDATION:
i.
AFFIRMATIVE: 14.
'NEGATIVE: Breting.
EXPLANATION OF VOTE:
"'BREIIN6: Whlle Installation instructions are supplied by the
manufacturer covering the intended floor construction, this
proposal would provide clarification to those who may not have
access to these instructions.
352-22: Accept
OMP 8
SUBMITTER: TSC-Approvedfor the Purpose
146 See the Technical Subcommittee "Recommendations" '
uncler the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "flndlngs" under the definition of
"Approved .for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
Delete the words "unless approved for the purpose."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-22: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
PRUPUSAL: 147 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The .language is permissive and does not
restrict the use of nonmetallic surface raceways. See the
attached opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
llO-16(a).
PANEL RECO~g~ENDATION: Reject.
PANEL COMMENT:' The present wording adequately reflects the
Panel's Intent.
VOTE ON PANELRECO~iENDATION: UnanimouslyAffirmative.
356-11: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PITOFOSA
' L-T." 153 See the Technical Subcommittee "Recommendations"
un--n'de'r-~-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Arti~:le 100.
PANEL RECO~ENDATION: Accept as Revised:
....Delete the words "approved for the purpose" and add the word
"approved" before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 353 -- MULTIOUTLET ASSEMBLY
353-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
148 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The language is permissive and does not
restrict the use of multloutlet assemblies. See the attached
opinion* of the San Diego City Attorney.
,
*See Border County Div. IAEI substantiation for proposal for
110~16(a).
PANEL RECOMMENDATION: Reject.
PANEL CDMMENT:' The present wording adequately reflects the
Fanel's Intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
356-12-(New): Reject
CMP 8
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
154 Change the, present Section 356-12 to 356-13 and
~dd a new 356-12 (under Part A) as follows:
356-12. Aligning and Sealing. Cellular metal floor raceways
shall be so Installed that all sections which are used as
.
raceways for conductors are aligoed and joined to p~ovide a
smooth raceway free of sharp edges or foreign materials.
Raceway Joints shall be sealed to prevent the entrance of water
and concrete mix as soon as possible after the ducts are secured
in place.
SUBSTANTIATION: The ends of adjoining sections of cellular
metal floor raceways must be lined up to prevent insulation
damage during the wire pulling process.. The design of cellular
metal floor'does not assure alignment and there are no specific
Code requirements for such an alignment. Accordingly, this has
caused problems in enforcement. Also, the joints must be taped
or sealed to prevent the entrance of water or concrete which
obviously can damage the conductor insulation when branch
circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is prlmarily a design consideration.
V'dTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Young.
353-2: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
I~TOPI~L-~.. 149 See the Technical Subco~ittee "Recommendations"
un--6"d~-F-tT~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the wOrds "unless approved for the purpose.".
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
t
ARTICLE 354 -- UNDERFLOOR RACEWAYS
354-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAE'I
150 In the f i r s t sentence, add the word "only" after
"permitted." In the third sentence, delete the word
"severe."
SUBSTANTIATION: The language is permissive and does not
155
352-1, Exception No. 1: Accept
CM°A 8
SUBMITTER: TSC-Approvedfor the Purpose
144 See the Technical Subcommittee "Recommendations"
un-"6Be'r--t-f~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~ENDATION: ~ccept as Revised:
Delete the words "approved for the purpose" and add at the end
of the exception: "where identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
restrict the use of underfloor raceways. See the attached
oplnion* of the San Diego City Attorney.
• *See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
P'Enel's Intent.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
354-15: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PKUPOSAL: 151 See the Technical Subcommittee "Recommendations"
un--n-d'e~-ElTe definitli)n of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
P.A.NEL RECOMMENDATION: Accept as Revised:
J Delete the words "approved for the purpose" and add "approved"
before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-8: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
145 See the Technical Subcommittee "Recommendations"
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
•"Delete the words "approved for the purpose for'which they are
used" and add the words "identified for such use."
VOTE ON PANELREC~NDATION: UnanimouslyAffirmative.
r
ARTICLE 356 -- CELLULAR METAL FLOORRACEWAYS
356-1: Reject
CMP 8
SUBMITTER: Charles T. Flachbarth, Walker Parkersburg Division
~ n c .
PROPOSAL: 152 Add a second sentence as follows:
"-"l~-6F'-Ehe purposes of this article, a cellular metal floor
consists of the entire floor area being covered with cellular
metal floor sections or a combination of cellular metal f l o o r
raceway sections and corrugated metal deck sections."
SUBSTANTIATION In somebuilding designs, there is confusion
'~egarding when a cellular metal floor raceway system as
described in Article 356 can be used, compared with an
underfloor raceway system as described in Article 354 can be
used. This proposed change will eliminate confusion regarding
when Article 356 applies or when Article 354 applies, without
changing the intention of the Code regarding the use of cellular
metal floor raceways or underfloor raceway systems.
PANEL RECOI~MENDATION: Reject.
FANEL COMMENT: No additional clarification would be achieved by
t h i s Proposal.
VOTE
ON PANELRECOMMENDATION:
i.
AFFIRMATIVE: 14.
'NEGATIVE: Breting.
EXPLANATION OF VOTE:
"'BREIIN6: Whlle Installation instructions are supplied by the
manufacturer covering the intended floor construction, this
proposal would provide clarification to those who may not have
access to these instructions.
352-22: Accept
OMP 8
SUBMITTER: TSC-Approvedfor the Purpose
146 See the Technical Subcommittee "Recommendations" '
uncler the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "flndlngs" under the definition of
"Approved .for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
Delete the words "unless approved for the purpose."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-22: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
PRUPUSAL: 147 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The .language is permissive and does not
restrict the use of nonmetallic surface raceways. See the
attached opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
llO-16(a).
PANEL RECO~g~ENDATION: Reject.
PANEL COMMENT:' The present wording adequately reflects the
Panel's Intent.
VOTE ON PANELRECO~iENDATION: UnanimouslyAffirmative.
356-11: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PITOFOSA
' L-T." 153 See the Technical Subcommittee "Recommendations"
un--n'de'r-~-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Arti~:le 100.
PANEL RECO~ENDATION: Accept as Revised:
....Delete the words "approved for the purpose" and add the word
"approved" before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 353 -- MULTIOUTLET ASSEMBLY
353-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
148 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The language is permissive and does not
restrict the use of multloutlet assemblies. See the attached
opinion* of the San Diego City Attorney.
,
*See Border County Div. IAEI substantiation for proposal for
110~16(a).
PANEL RECOMMENDATION: Reject.
PANEL CDMMENT:' The present wording adequately reflects the
Fanel's Intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
356-12-(New): Reject
CMP 8
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
154 Change the, present Section 356-12 to 356-13 and
~dd a new 356-12 (under Part A) as follows:
356-12. Aligning and Sealing. Cellular metal floor raceways
shall be so Installed that all sections which are used as
.
raceways for conductors are aligoed and joined to p~ovide a
smooth raceway free of sharp edges or foreign materials.
Raceway Joints shall be sealed to prevent the entrance of water
and concrete mix as soon as possible after the ducts are secured
in place.
SUBSTANTIATION: The ends of adjoining sections of cellular
metal floor raceways must be lined up to prevent insulation
damage during the wire pulling process.. The design of cellular
metal floor'does not assure alignment and there are no specific
Code requirements for such an alignment. Accordingly, this has
caused problems in enforcement. Also, the joints must be taped
or sealed to prevent the entrance of water or concrete which
obviously can damage the conductor insulation when branch
circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is prlmarily a design consideration.
V'dTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Young.
353-2: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
I~TOPI~L-~.. 149 See the Technical Subco~ittee "Recommendations"
un--6"d~-F-tT~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the wOrds "unless approved for the purpose.".
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
t
ARTICLE 354 -- UNDERFLOOR RACEWAYS
354-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAE'I
150 In the f i r s t sentence, add the word "only" after
"permitted." In the third sentence, delete the word
"severe."
SUBSTANTIATION: The language is permissive and does not
155
352-1, Exception No. 1: Accept
CM°A 8
SUBMITTER: TSC-Approvedfor the Purpose
144 See the Technical Subcommittee "Recommendations"
un-"6Be'r--t-f~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOI~ENDATION: ~ccept as Revised:
Delete the words "approved for the purpose" and add at the end
of the exception: "where identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
restrict the use of underfloor raceways. See the attached
oplnion* of the San Diego City Attorney.
• *See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
P'Enel's Intent.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
354-15: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PKUPOSAL: 151 See the Technical Subcommittee "Recommendations"
un--n-d'e~-ElTe definitli)n of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
P.A.NEL RECOMMENDATION: Accept as Revised:
J Delete the words "approved for the purpose" and add "approved"
before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-8: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
145 See the Technical Subcommittee "Recommendations"
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
•"Delete the words "approved for the purpose for'which they are
used" and add the words "identified for such use."
VOTE ON PANELREC~NDATION: UnanimouslyAffirmative.
r
ARTICLE 356 -- CELLULAR METAL FLOORRACEWAYS
356-1: Reject
CMP 8
SUBMITTER: Charles T. Flachbarth, Walker Parkersburg Division
~ n c .
PROPOSAL: 152 Add a second sentence as follows:
"-"l~-6F'-Ehe purposes of this article, a cellular metal floor
consists of the entire floor area being covered with cellular
metal floor sections or a combination of cellular metal f l o o r
raceway sections and corrugated metal deck sections."
SUBSTANTIATION In somebuilding designs, there is confusion
'~egarding when a cellular metal floor raceway system as
described in Article 356 can be used, compared with an
underfloor raceway system as described in Article 354 can be
used. This proposed change will eliminate confusion regarding
when Article 356 applies or when Article 354 applies, without
changing the intention of the Code regarding the use of cellular
metal floor raceways or underfloor raceway systems.
PANEL RECOI~MENDATION: Reject.
FANEL COMMENT: No additional clarification would be achieved by
t h i s Proposal.
VOTE
ON PANELRECOMMENDATION:
i.
AFFIRMATIVE: 14.
'NEGATIVE: Breting.
EXPLANATION OF VOTE:
"'BREIIN6: Whlle Installation instructions are supplied by the
manufacturer covering the intended floor construction, this
proposal would provide clarification to those who may not have
access to these instructions.
352-22: Accept
OMP 8
SUBMITTER: TSC-Approvedfor the Purpose
146 See the Technical Subcommittee "Recommendations" '
uncler the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "flndlngs" under the definition of
"Approved .for the Purpose" in Article 100.
PANEL RECO~ENDATION: Accept as Revised:
Delete the words "unless approved for the purpose."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
352-22: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
PRUPUSAL: 147 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The .language is permissive and does not
restrict the use of nonmetallic surface raceways. See the
attached opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
llO-16(a).
PANEL RECO~g~ENDATION: Reject.
PANEL COMMENT:' The present wording adequately reflects the
Panel's Intent.
VOTE ON PANELRECO~iENDATION: UnanimouslyAffirmative.
356-11: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
PITOFOSA
' L-T." 153 See the Technical Subcommittee "Recommendations"
un--n'de'r-~-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Arti~:le 100.
PANEL RECO~ENDATION: Accept as Revised:
....Delete the words "approved for the purpose" and add the word
"approved" before the word " f i t t i n g s . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 353 -- MULTIOUTLET ASSEMBLY
353-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAEI
148 In the f i r s t sentence, add the word "only" after
"permitted." In the second sentence (2), delete the
word "severe."
SUBSTANTIATION: The language is permissive and does not
restrict the use of multloutlet assemblies. See the attached
opinion* of the San Diego City Attorney.
,
*See Border County Div. IAEI substantiation for proposal for
110~16(a).
PANEL RECOMMENDATION: Reject.
PANEL CDMMENT:' The present wording adequately reflects the
Fanel's Intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
356-12-(New): Reject
CMP 8
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
154 Change the, present Section 356-12 to 356-13 and
~dd a new 356-12 (under Part A) as follows:
356-12. Aligning and Sealing. Cellular metal floor raceways
shall be so Installed that all sections which are used as
.
raceways for conductors are aligoed and joined to p~ovide a
smooth raceway free of sharp edges or foreign materials.
Raceway Joints shall be sealed to prevent the entrance of water
and concrete mix as soon as possible after the ducts are secured
in place.
SUBSTANTIATION: The ends of adjoining sections of cellular
metal floor raceways must be lined up to prevent insulation
damage during the wire pulling process.. The design of cellular
metal floor'does not assure alignment and there are no specific
Code requirements for such an alignment. Accordingly, this has
caused problems in enforcement. Also, the joints must be taped
or sealed to prevent the entrance of water or concrete which
obviously can damage the conductor insulation when branch
circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is prlmarily a design consideration.
V'dTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Young.
353-2: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
I~TOPI~L-~.. 149 See the Technical Subco~ittee "Recommendations"
un--6"d~-F-tT~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the wOrds "unless approved for the purpose.".
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
t
ARTICLE 354 -- UNDERFLOOR RACEWAYS
354-2: Reject
CMP 8
SUBMITTER: O. E. Dillon, Border County Div. IAE'I
150 In the f i r s t sentence, add the word "only" after
"permitted." In the third sentence, delete the word
"severe."
SUBSTANTIATION: The language is permissive and does not
155
EXPLANATION OF VOTE:
YOUNG: The Code is not considered to be a design standard but
in my opinion to require a product to be properly protected from
damage through transit and installation is not a design
requirement.
ARTICLE 362 -- WIREWAYS
362-5: Accept
CMP 8
SUBMITTER: CMP 8
PROPOSAL: 158A Revise section to read as follows: Wireways
~ t
contain more than 30 current-carrying conductors at
any cross section. Conductors for signaling circuits or
controller conductors between a motor and its starter and used
only for starting duty shall not be considered as currentcarrying conductors.
The sum~o~ the cross-sectional areas of all contained
conductors at any cross section of the wireway shall not exceed
20 percent of the interior cross-sectional area of the wireway.
The derating factors specified in Note 8 to Tables 310-16
through 310-19 shall not be applicable to the 30
L
current-carrying conductors at 20 percent f i l ] specified above.
Exception No. l: Where the derating factors specified in Note
8 of Table 3]0-]6 through 310-19 are applied, the number of
current-carrying conductors shall not be limited but the sum of
the cross-sectional area of all contained conductors at any
cross section of the wireway shall not e~ceed 20 percent of the
interior cross-sectlonal area of the wireway.
Exception No. 2: As provided in Section 520-5, the 30
conductor limitation does not apply for theaters and similar
locations.
Exception No. 3: As provided in Section 620-32, the 20 percent
f i l l limitation does not apply for elevators and dumbwaiters.
SUBSTANTIATION: Clarificat!on.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
356-12-(New): Reject
CMP 8
SUBMITTER: Southwestern Section IAEI
I~ROP-O-SA
' I~-~
•. 155 Change the present Section 356-12 to 356-13 and
~ w
356-12 (under part A) to read:
356-12. Aligning and Sealing. Cellular metal floor raceways
shall be so installed that all sections which are used as
raceways for conductors are aligned and joined to provide a
smooth raceway free of sharp edges or foreign materials.
Raceway joints shall be sealed to prevent the entrance of water
,and concrete mix as soon as possible after the ducts are secured
in place.
SUBSTANTIATION: The ends of adjoining sections of, cellular
metal floor raceways must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
metal floor does not assure alignment and there are no specific
Code requirements for such an alignment. Accordingly, this has
caused problems in enforcement. Also the Joints must be taped
or sealed to prevent the entrance of water or concrete which
obviously can damage the conductor insulation when branch
circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primaril~ a design consideration.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Young.
EXPLANATION OF VOTE:
YOUNG: See comments for Proposal No. 154.
362-5: Reject
CMP 8
SUBMIT~
8
PROPOSAL: 15BB Revise section to read as follows: The number
~ctors
permitted in a wireway shall be such that the sum
of the cross-sectional area of the contained conductors shall
not exceed 20 percent f i l l of the wireway. The deratihg factors
specified in Note 8 of Tables 310-16 through 310-19 shall not be
applicable to the current-carrying conductors in wireways.
Exception: As provided in Section 620-32, the 20 percent f i l l
limitation does not apply for elevators and dumbwaiters.
SUBSTANTIATION: Clarification.
PANEL MECOMMEMDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 158A.
VOlt UN PANEL RECOM~MENDATION: UnanimouslyAffirmative./
ARTICLE 358 -- CELLULAR CONCRETE FLOOR P,ACEWAYS
358-4: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
!sI~3~-AL-~." 156 See the Technical Subcommittee "Recommendations"
unOer the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" unde~ the definition of
"Approved for the Purpose" in Article 100;
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and add "approved"
before the word " f i t t i n g s ~ " .
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-10: Accept
.
CMP 8
SUBMITTER: H. F. van der Vonrt Cleveland, Ohio
I~TOIIO'S'AL-~.
• 15g Insert: "rigid nonmetallic conduit" after
~diate
n~tal conduit." Then add new sentence at end of
section to read: "Where rigid nonmetallic conduit is used,
connection of equipment grounding conductors in the rigid
nonmetalllc~condult to the wireway shall comply with Sections
250-113 and 250-118."
SUBSTANTIATION: This use of rigid nonmetallic conduit is now
acceptable under Article 347. The change in Article 362 will
bring i t into conformity with other parts of the Code.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
358-12-(New): Reject
CMP 8
SUBMII-rER: R. S. Pinkerton, Los Angeles, CA
157 Add a •new section as follows:
~'3~r~I-2"7-. Aligning and Sealing. Cellular concrete floor raceways
shall be so installed that all sections used as raceways for
conductors are aligned and joined to provide a smooth raceway
free of sharp edges or foreign materials. RacewayJoints shall
be sealed to prevent the entrance of water and concrete mix as
soon as possible after the ducts are secured in place.
SUBSTANTIATION: The ends of adjoining sections of cellular
concrete floor raceway must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
concrete floor raceway does not assure alignment and there are
no specific Code requirements for such'an alignment.
Accordingly, this has caused problems in enforcement. Also, the
joints must be taped or sealed to prevent the entrance of water
or concrete which obviously can damage the conductor insulation
when branch circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
362-11-(New): Reject
CMP 8
SUBMII'TER: R. S. Pinkerton, Los Angeles, CA
160 Add a new section as follows:
~ . .
Posltion. Wi~eways may be installed wlth the cover
face in a downward position provided suitable supports for
conductors are installed therein at points not more than 3 f e e t
apart.
SUBSTANTIATION: In the definition of a wireway In Section 362-1
appears the statement "In which conductors are laid in place
after the wireway has beeh installed." Thls In~)lies and has
been interpreted ~o n~an that wireways must be installed with
the cover on the'side or top for conductors to be laid in
place. But in many applications, this is an impracticle
position. Where conductors have sultable Insulatlng supports,
they can be positioned in a wireway with the cpver facing down
without danger of damaging the conductor insulation. This
provision has been permitted in the City of Los Angeles for many
years with no reported failures.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Such practice is not prohibited by present Code.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
358-12-(New): Reject
CMP 8
SUBMITTER: Southwestern Section IAEI
PROPOSAL: 158
~rS"l~'1-'~T-.Aligning and Sealing. Cellular concrete floor raceways
shall be so installed that all sections used as raceways for
conductors are aligned and Joined to provide a smooth raceway
free of sharp edges or foreign materials. RacewayJoints shall
be sealed to prevent the entrance of water and concrete mix as
soon as possible after the ducts are secured in place.
SUBSTANTIATION: The ends of adjoining section of cellular
concrete floor raceway must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
concrete floor raceways does not assure alignment and there are
no specific Code requirements for such an alignment.
Accordingly, this has caused problems in enforcement. Also, the
joints must be taped or sealed to prevent the entrance ~f water
or concrete which obviously can damage the conductor insulation
when branch circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-12-(New): Reject
CMI~ 8
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
PROPOSAL: 161 Add a new section as follows:
~'~-~T~-.Working Space. At least 12 inches of working space
shall be provided between the cover of a wireway and walls,
ceilings or similar obstructions.
SUBSTANTIATION: The intent of this requirement is to provide a
safe work environment for electricians who will be performing
maintenance work or making additions to existing wireway
156
EXPLANATION OF VOTE:
YOUNG: The Code is not considered to be a design standard but
in my opinion to require a product to be properly protected from
damage through transit and installation is not a design
requirement.
ARTICLE 362 -- WIREWAYS
362-5: Accept
CMP 8
SUBMITTER: CMP 8
PROPOSAL: 158A Revise section to read as follows: Wireways
~ t
contain more than 30 current-carrying conductors at
any cross section. Conductors for signaling circuits or
controller conductors between a motor and its starter and used
only for starting duty shall not be considered as currentcarrying conductors.
The sum~o~ the cross-sectional areas of all contained
conductors at any cross section of the wireway shall not exceed
20 percent of the interior cross-sectional area of the wireway.
The derating factors specified in Note 8 to Tables 310-16
through 310-19 shall not be applicable to the 30
L
current-carrying conductors at 20 percent f i l ] specified above.
Exception No. l: Where the derating factors specified in Note
8 of Table 3]0-]6 through 310-19 are applied, the number of
current-carrying conductors shall not be limited but the sum of
the cross-sectional area of all contained conductors at any
cross section of the wireway shall not e~ceed 20 percent of the
interior cross-sectlonal area of the wireway.
Exception No. 2: As provided in Section 520-5, the 30
conductor limitation does not apply for theaters and similar
locations.
Exception No. 3: As provided in Section 620-32, the 20 percent
f i l l limitation does not apply for elevators and dumbwaiters.
SUBSTANTIATION: Clarificat!on.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
356-12-(New): Reject
CMP 8
SUBMITTER: Southwestern Section IAEI
I~ROP-O-SA
' I~-~
•. 155 Change the present Section 356-12 to 356-13 and
~ w
356-12 (under part A) to read:
356-12. Aligning and Sealing. Cellular metal floor raceways
shall be so installed that all sections which are used as
raceways for conductors are aligned and joined to provide a
smooth raceway free of sharp edges or foreign materials.
Raceway joints shall be sealed to prevent the entrance of water
,and concrete mix as soon as possible after the ducts are secured
in place.
SUBSTANTIATION: The ends of adjoining sections of, cellular
metal floor raceways must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
metal floor does not assure alignment and there are no specific
Code requirements for such an alignment. Accordingly, this has
caused problems in enforcement. Also the Joints must be taped
or sealed to prevent the entrance of water or concrete which
obviously can damage the conductor insulation when branch
circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primaril~ a design consideration.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Young.
EXPLANATION OF VOTE:
YOUNG: See comments for Proposal No. 154.
362-5: Reject
CMP 8
SUBMIT~
8
PROPOSAL: 15BB Revise section to read as follows: The number
~ctors
permitted in a wireway shall be such that the sum
of the cross-sectional area of the contained conductors shall
not exceed 20 percent f i l l of the wireway. The deratihg factors
specified in Note 8 of Tables 310-16 through 310-19 shall not be
applicable to the current-carrying conductors in wireways.
Exception: As provided in Section 620-32, the 20 percent f i l l
limitation does not apply for elevators and dumbwaiters.
SUBSTANTIATION: Clarification.
PANEL MECOMMEMDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 158A.
VOlt UN PANEL RECOM~MENDATION: UnanimouslyAffirmative./
ARTICLE 358 -- CELLULAR CONCRETE FLOOR P,ACEWAYS
358-4: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
!sI~3~-AL-~." 156 See the Technical Subcommittee "Recommendations"
unOer the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" unde~ the definition of
"Approved for the Purpose" in Article 100;
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and add "approved"
before the word " f i t t i n g s ~ " .
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-10: Accept
.
CMP 8
SUBMITTER: H. F. van der Vonrt Cleveland, Ohio
I~TOIIO'S'AL-~.
• 15g Insert: "rigid nonmetallic conduit" after
~diate
n~tal conduit." Then add new sentence at end of
section to read: "Where rigid nonmetallic conduit is used,
connection of equipment grounding conductors in the rigid
nonmetalllc~condult to the wireway shall comply with Sections
250-113 and 250-118."
SUBSTANTIATION: This use of rigid nonmetallic conduit is now
acceptable under Article 347. The change in Article 362 will
bring i t into conformity with other parts of the Code.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
358-12-(New): Reject
CMP 8
SUBMII-rER: R. S. Pinkerton, Los Angeles, CA
157 Add a •new section as follows:
~'3~r~I-2"7-. Aligning and Sealing. Cellular concrete floor raceways
shall be so installed that all sections used as raceways for
conductors are aligned and joined to provide a smooth raceway
free of sharp edges or foreign materials. RacewayJoints shall
be sealed to prevent the entrance of water and concrete mix as
soon as possible after the ducts are secured in place.
SUBSTANTIATION: The ends of adjoining sections of cellular
concrete floor raceway must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
concrete floor raceway does not assure alignment and there are
no specific Code requirements for such'an alignment.
Accordingly, this has caused problems in enforcement. Also, the
joints must be taped or sealed to prevent the entrance of water
or concrete which obviously can damage the conductor insulation
when branch circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
362-11-(New): Reject
CMP 8
SUBMII'TER: R. S. Pinkerton, Los Angeles, CA
160 Add a new section as follows:
~ . .
Posltion. Wi~eways may be installed wlth the cover
face in a downward position provided suitable supports for
conductors are installed therein at points not more than 3 f e e t
apart.
SUBSTANTIATION: In the definition of a wireway In Section 362-1
appears the statement "In which conductors are laid in place
after the wireway has beeh installed." Thls In~)lies and has
been interpreted ~o n~an that wireways must be installed with
the cover on the'side or top for conductors to be laid in
place. But in many applications, this is an impracticle
position. Where conductors have sultable Insulatlng supports,
they can be positioned in a wireway with the cpver facing down
without danger of damaging the conductor insulation. This
provision has been permitted in the City of Los Angeles for many
years with no reported failures.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Such practice is not prohibited by present Code.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
358-12-(New): Reject
CMP 8
SUBMITTER: Southwestern Section IAEI
PROPOSAL: 158
~rS"l~'1-'~T-.Aligning and Sealing. Cellular concrete floor raceways
shall be so installed that all sections used as raceways for
conductors are aligned and Joined to provide a smooth raceway
free of sharp edges or foreign materials. RacewayJoints shall
be sealed to prevent the entrance of water and concrete mix as
soon as possible after the ducts are secured in place.
SUBSTANTIATION: The ends of adjoining section of cellular
concrete floor raceway must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
concrete floor raceways does not assure alignment and there are
no specific Code requirements for such an alignment.
Accordingly, this has caused problems in enforcement. Also, the
joints must be taped or sealed to prevent the entrance ~f water
or concrete which obviously can damage the conductor insulation
when branch circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-12-(New): Reject
CMI~ 8
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
PROPOSAL: 161 Add a new section as follows:
~'~-~T~-.Working Space. At least 12 inches of working space
shall be provided between the cover of a wireway and walls,
ceilings or similar obstructions.
SUBSTANTIATION: The intent of this requirement is to provide a
safe work environment for electricians who will be performing
maintenance work or making additions to existing wireway
156
EXPLANATION OF VOTE:
YOUNG: The Code is not considered to be a design standard but
in my opinion to require a product to be properly protected from
damage through transit and installation is not a design
requirement.
ARTICLE 362 -- WIREWAYS
362-5: Accept
CMP 8
SUBMITTER: CMP 8
PROPOSAL: 158A Revise section to read as follows: Wireways
~ t
contain more than 30 current-carrying conductors at
any cross section. Conductors for signaling circuits or
controller conductors between a motor and its starter and used
only for starting duty shall not be considered as currentcarrying conductors.
The sum~o~ the cross-sectional areas of all contained
conductors at any cross section of the wireway shall not exceed
20 percent of the interior cross-sectional area of the wireway.
The derating factors specified in Note 8 to Tables 310-16
through 310-19 shall not be applicable to the 30
L
current-carrying conductors at 20 percent f i l ] specified above.
Exception No. l: Where the derating factors specified in Note
8 of Table 3]0-]6 through 310-19 are applied, the number of
current-carrying conductors shall not be limited but the sum of
the cross-sectional area of all contained conductors at any
cross section of the wireway shall not e~ceed 20 percent of the
interior cross-sectlonal area of the wireway.
Exception No. 2: As provided in Section 520-5, the 30
conductor limitation does not apply for theaters and similar
locations.
Exception No. 3: As provided in Section 620-32, the 20 percent
f i l l limitation does not apply for elevators and dumbwaiters.
SUBSTANTIATION: Clarificat!on.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
356-12-(New): Reject
CMP 8
SUBMITTER: Southwestern Section IAEI
I~ROP-O-SA
' I~-~
•. 155 Change the present Section 356-12 to 356-13 and
~ w
356-12 (under part A) to read:
356-12. Aligning and Sealing. Cellular metal floor raceways
shall be so installed that all sections which are used as
raceways for conductors are aligned and joined to provide a
smooth raceway free of sharp edges or foreign materials.
Raceway joints shall be sealed to prevent the entrance of water
,and concrete mix as soon as possible after the ducts are secured
in place.
SUBSTANTIATION: The ends of adjoining sections of, cellular
metal floor raceways must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
metal floor does not assure alignment and there are no specific
Code requirements for such an alignment. Accordingly, this has
caused problems in enforcement. Also the Joints must be taped
or sealed to prevent the entrance of water or concrete which
obviously can damage the conductor insulation when branch
circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primaril~ a design consideration.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Young.
EXPLANATION OF VOTE:
YOUNG: See comments for Proposal No. 154.
362-5: Reject
CMP 8
SUBMIT~
8
PROPOSAL: 15BB Revise section to read as follows: The number
~ctors
permitted in a wireway shall be such that the sum
of the cross-sectional area of the contained conductors shall
not exceed 20 percent f i l l of the wireway. The deratihg factors
specified in Note 8 of Tables 310-16 through 310-19 shall not be
applicable to the current-carrying conductors in wireways.
Exception: As provided in Section 620-32, the 20 percent f i l l
limitation does not apply for elevators and dumbwaiters.
SUBSTANTIATION: Clarification.
PANEL MECOMMEMDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 158A.
VOlt UN PANEL RECOM~MENDATION: UnanimouslyAffirmative./
ARTICLE 358 -- CELLULAR CONCRETE FLOOR P,ACEWAYS
358-4: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
!sI~3~-AL-~." 156 See the Technical Subcommittee "Recommendations"
unOer the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" unde~ the definition of
"Approved for the Purpose" in Article 100;
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and add "approved"
before the word " f i t t i n g s ~ " .
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-10: Accept
.
CMP 8
SUBMITTER: H. F. van der Vonrt Cleveland, Ohio
I~TOIIO'S'AL-~.
• 15g Insert: "rigid nonmetallic conduit" after
~diate
n~tal conduit." Then add new sentence at end of
section to read: "Where rigid nonmetallic conduit is used,
connection of equipment grounding conductors in the rigid
nonmetalllc~condult to the wireway shall comply with Sections
250-113 and 250-118."
SUBSTANTIATION: This use of rigid nonmetallic conduit is now
acceptable under Article 347. The change in Article 362 will
bring i t into conformity with other parts of the Code.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
358-12-(New): Reject
CMP 8
SUBMII-rER: R. S. Pinkerton, Los Angeles, CA
157 Add a •new section as follows:
~'3~r~I-2"7-. Aligning and Sealing. Cellular concrete floor raceways
shall be so installed that all sections used as raceways for
conductors are aligned and joined to provide a smooth raceway
free of sharp edges or foreign materials. RacewayJoints shall
be sealed to prevent the entrance of water and concrete mix as
soon as possible after the ducts are secured in place.
SUBSTANTIATION: The ends of adjoining sections of cellular
concrete floor raceway must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
concrete floor raceway does not assure alignment and there are
no specific Code requirements for such'an alignment.
Accordingly, this has caused problems in enforcement. Also, the
joints must be taped or sealed to prevent the entrance of water
or concrete which obviously can damage the conductor insulation
when branch circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
362-11-(New): Reject
CMP 8
SUBMII'TER: R. S. Pinkerton, Los Angeles, CA
160 Add a new section as follows:
~ . .
Posltion. Wi~eways may be installed wlth the cover
face in a downward position provided suitable supports for
conductors are installed therein at points not more than 3 f e e t
apart.
SUBSTANTIATION: In the definition of a wireway In Section 362-1
appears the statement "In which conductors are laid in place
after the wireway has beeh installed." Thls In~)lies and has
been interpreted ~o n~an that wireways must be installed with
the cover on the'side or top for conductors to be laid in
place. But in many applications, this is an impracticle
position. Where conductors have sultable Insulatlng supports,
they can be positioned in a wireway with the cpver facing down
without danger of damaging the conductor insulation. This
provision has been permitted in the City of Los Angeles for many
years with no reported failures.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Such practice is not prohibited by present Code.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
358-12-(New): Reject
CMP 8
SUBMITTER: Southwestern Section IAEI
PROPOSAL: 158
~rS"l~'1-'~T-.Aligning and Sealing. Cellular concrete floor raceways
shall be so installed that all sections used as raceways for
conductors are aligned and Joined to provide a smooth raceway
free of sharp edges or foreign materials. RacewayJoints shall
be sealed to prevent the entrance of water and concrete mix as
soon as possible after the ducts are secured in place.
SUBSTANTIATION: The ends of adjoining section of cellular
concrete floor raceway must be lined up to prevent insulation
damage during the wire pulling process. The design of cellular
concrete floor raceways does not assure alignment and there are
no specific Code requirements for such an alignment.
Accordingly, this has caused problems in enforcement. Also, the
joints must be taped or sealed to prevent the entrance ~f water
or concrete which obviously can damage the conductor insulation
when branch circuits are installed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-12-(New): Reject
CMI~ 8
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
PROPOSAL: 161 Add a new section as follows:
~'~-~T~-.Working Space. At least 12 inches of working space
shall be provided between the cover of a wireway and walls,
ceilings or similar obstructions.
SUBSTANTIATION: The intent of this requirement is to provide a
safe work environment for electricians who will be performing
maintenance work or making additions to existing wireway
156
installations. Maintenance electricians should have sufficient
workspace in front of a wireway that they can look inside and
examine the. condition of conductor insulation for splice
Insulation before pulling wires out of a wireway. Experience
has shown'that conductor's insulation does become damaged and
the insulation on splices can open up Which can present a severe
shock hazard to people who reach into the wiroway while working
"blind". A 12 Inch minimum working space is a reasonable and
practical dimension and will greatly enhance safe working
conditions for maintenance electricians.
PANEL RECOI~MENDATION: Reject.
PANEL COMMENT: Already covered by Section llO-16.
volt uN PANELRECO~WIENDATION: UnanimouslyAffirmative.
364-5, Exception No. 2: Reject
CMP 8
SUBMII"rER: TSC-Approvedfor the Purpose
PROPDSAL: 166 See the Technical Subcommittee "Recammendations"
un--B-d-~-~--tITe definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the clefinitlon of
"Approved for the Purpose" in Article 100.
PANEL RECOf~IENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 165.
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
364-8: Accept
CMP 8
SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.
IPRUPO~AL: 167 Add a sentence as follows:
~ l e
cord assembly connections may be made directly to the
=load end terminals of a busway plug-ln device, providing the
connection includes a suitable tension take-up device on the
cord.
SUBSTANTIATION: Section 364-8 l i s t s eight types of equipment
permitted for connection to busway but contains no guidelines
for the make-up of such connections. In the case of cord
assembly connections to busway plug-in devices, seekers of
guidance may be drawn to 400-7(b). This paragraph is aimed
primarily at fixed location connections and requires a
receptacle outlet on the power supply plus an attachment plug on
the cord.
Minimizes the possibility of unnecessary components being
incorporated in the connection.
PANEL RECO~ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
362-12-(New): Reject
CMP 8
SUBMIl-rER: SouthwesternSection IAEI
162
Position. Wiroways may be installed with the cover
face in a downward position provided suitable supports for
conductors are installed therein at points not more than three
feet apart.
SUBSTANTIATION: in the definition of a wlreway in Section 362-i
appears the statement "inwhich conductors are laid in place
after the wireway has been installed." This implies and has
been interpreted to mean that wireways must be installed with
the cover on the side or top for conductors to be laid in
place. But in many applications, this is an impractical
position. Where conductors have suitable insulating supports,
they can be positioned in a wireway with the cover facing down
without danger of ,damaging the conductor insulation. This
provision has been permitted in the City of Los Angeles for many
years with no reported failures.
PANEL RECOf~4ENDATION: Reject.
PANEL CO,WENT: Such practice is not prohibited by present Code.
VOTE ON PANELRECO~4ENDATION: UnanimouslyAffirmative.
364-8: Accept
CMP
SUBMITTER: H. F. van der Voort, Cleveland, Ohio
~KUPU3AL: 168 Add "rigid nonmetallic conduit" after
~diate,metal
conduit." Then add now sentence at end of
section,to read: "Where rigid nonmetallic conduit is used,
connection of equipment grounding conductors in the rigid
nonmetallic conduit to the wireway shall comply with Sections
250-113 and 250-118."
SUBSTANTIATION: This use of rigid nonmetallic conduit is' now
acceptable under Article 347. The change in Article 364 will
bring i t into conformity with other parts of the Code.
PANEL RECO~V~4ENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-13-(New): Reject
CMP 8
SUBMITTER: SouthwesternSection IAEI
]~TOI~O~TAI--~
•. 163
~3~"~[~-.Working Space. At least 12 inches of working space
shall be provided between the cover of a wiroway and walls,,
ceilings or similar obstructions.
SUBSTANTIATION: The intent of this requirement is to provide a
Safe work environment for electricians wi~o will be performing
maintenance work or making additions to existing wireway
installations. Maintenance electricians should have sufficient
workspace in front of a wiroway that they can look inside and
ekamine the condition of conductor Insulation for splice
insulation before pulling wires out of a wireway. Experience
has shown that conductor's insulatlon does become damaged and
-the insulation on splices can open up which can present a severe
shock hazard to people who reach into the wireway while working
'blind'. A twelve inch minimum working space is a reasonable
and practical dimension and will greatly enhance safe working
conditions for maintenance electricians.
PANEL RECO~ENDATION: Reject.
PANEL COf~ENT: Already covered by Section llO-16.
VOtE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364L12: Reject
CMP 8
SUBMITTER: David J. Snitzer, City of Los Angeles Code Advisory
PROPOSAL: 169 Add note as follows:
~Overcurrent
devices on busways shall be installed in
accordancewith the requirements of Section 380-8.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The cross reference is redundant.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364-12, FPN-(New): Reject
SUBMII-fER: SouthwesternSection IAEI
HRUPU3AL: 170 Fine Print Note.
~rrent
devices on busways shall be installed in
accordance,with the requirements of Section 3~-8.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel Action on Proposal No. 169.
VOTE ON PANELRECOF~IENDATION: UnanimouslyAffirmative.
ARTICLE 364 -- BUSWAYS
364-4(b): Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
I}ITOI~-~.• 164 See the Technical Subcommittee "Reco~nendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "unless specifically approved for the
purpose" and add "unless identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
CMP 8
ARTICLE 365 -- CABLEBUS
365-2: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
HRUPU~AL: 171 See the Technical Subcofm~Ittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and substitute
"identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364-5, Exception No. 1: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
?ITOI~S'AL-~: 165 See the Technical Subcommittee "Reco~vnendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC."findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Revise 364-5 of the NEC as follows: "Buswaysshall be
securely supported at intervals not exceeding 5 feet unless
otherwise designed and marked." Delete Exception Nos. I and 2.
VOTE ON PANEL RECOMI~IENDATION:' Unanimously Affirmative.
365-8: Accept
CMP ,8
SUBMITTER: TSC-Approvedfor the Purpose
]~l~-OIiS-S~i~l~-~•. 172 See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
157
(c) Electric-discharge lampholders of' the screw-shell type
are mounted not less than 8 feet above the floor.
When the above conditions are met, fluorescent, mercury-vapor,
metal-halide, high-pressure sodium, low-pressure sodium and/or
incandescent fixtures may be supplied by 480/277 volt, grounded
wye circuit -- with loads connected phase-to-neutral and/or
phase-to-phase. Such circuits operate at 277 volts to ground that "is, not over 300 volts to ground -- even when 480 volt
ballasts are connected phase-to-phase.
The present Code restricts the use of Flat Cable to Feeding
Fixtures with 277 volt ballasts. With the increasing demand for
480 ballast fixtures fed from a 480/277 grounded wye system i t
is sound engineering to revise the' Code as proposed to permit
the wiring of 480 ballasts with Flat Cable.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL"RECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 363 -- FLAT CABLEASSEMBLIES
363-i: Accept
~
CMP 7
SUBMITTER: TSC-Approvedfor the Purpose
!bl~rOl~'X~-T.• 117 See the Tecl~nical Subcommittee "Reco~endations"
definition of "Approved for the Purpose" in Article
100,
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete "approved for the purpose."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
/
363:4: Accept
CMP 7
SUBMITTER: TSC-Approvedfor the Purpose
l}ITOl~'AIL-~.
• 118 See the Technical Subcommittee "Recommendations"
un--n-d~-r-[ITe definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the 'definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete "specifically approved for the purpose" in (1) and (4).
Insert "suitable f o r the application" in (I) and "identified for
use in wet locations" in (4).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-10: Accept
CMP 7
SUBMITTER: TSC-Approvedfor the Purpose
122 See the Technical Subcommittee "Recommendations"
un-G~-d~-~--t'ffe definition of "Approved for the P~rpose" in Article,
100.
SUBSTANTIATION: See the TSC "findings'; under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete "approved for the purpose" and replace with "identified
for the use.°
VOTE ONPANEL RECOMMENDATION: Unanimously Affirmative,
363-5: Accept
CMP 7
SUBMI1-TER: TSC-Approvedfor the Purpose
]~TOP-O-~Z:-." 119 See the Technical Subcommittee "Recommendations"
un--n-d~--E~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete "approved for the purpose" and insert "identified for
the use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-11: Accept
CMP 7
SUBMITTER: TSC-Approvedfor the Purpose
123 See the Technical Subcommittee "Recommendations"
un--6-d-e~--t-~e definition of "Approved for the Purpose" In Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECO~MENDATION: Accept as Revised:
Delete "approved ~or the purpose" in both paragraphs and
replace with "identified for the use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-9: Accept
CMP 7
SUBMITTER: S.J. Casasanta, West Hartford, CT
120 Revise as follows:
~ s
shall be made in approved Junction boxes using
approved wiring methods.
SUBSTANTIATION: Use of approved terminal blocks has proved
tedious and time-consuming. Manyinstallations have been made
where standard approved wiring methods, such as wire nuts, were
permitted by the local inspector.
Individual conductors of f l a t cable have been identified with
imprinted marking to assure that phases are properly connected.
The imprint marking will substitute for the color code marking
on the terminal block.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-12~ Accept
CMP 7
SUBMITTER: CMP 7
$1R-OIO-SA
' -L-~. 123A Delete "approved for the purpose~ and replace
w-Tt'h--~T~entifled for the use."
SUBSTANTCATION: To comply with TSC on Approved for the Purpose
recommendatlons.
PANEL RECOI~MENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-14: Accept
CMP 7
SUBMITTER: S.J, Casasanta, West Hartford, CT
124 Revise as follows:
All extensions from f l a t cabl@ assemblies shall be made by
approved wiring methods, within the Junction boxes, installed at
either end of the f l a t cable assembly runs.
SUBSTANTIATION: Use of terminal blocks has proved tedious and
time-consuming. Standard approved wiring methods such as wire
nuts have been used and permitted by the local inspector.
Individual conductors of f l a t cable have.been 'identified with
imprinted marking to assure that phases are properly connected.
The imprint marking wlll substitute for the color code marking
on the terminal block.
•
PANEL RECOMMENDATION: Accept.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-10: Accept
CMP 7
SUBMITTER: S.J. Casasanta, West Hartford, CT
PROPOSAL: 121 Revise as follows:
a--~hall
be made between any phase conductor and the neutral
or any other phase conductor by means of devices and f i t t i n g s
approved for the purpose. Tap devices shall be rated at not
less than 15 amperes or more than 300 volts and they shall be
color-coded in accordance with the requirements of Section
1363_2o .
~UBSTANTIATION:
.
.
Section 210-6. Permits branch circuits with voltages not
exceeding 300 volts to ground per the following:
(a) Voltage to Ground.
.
.
.
Exception No. 1: The voltage shall not exceed 300 volts to
ground on branch circuits in industrial establishments where all
of the following condi¢ions are met:
(a) The conditions of maintenance and supervision indicate
that only qualified persons will service the lighting fixtures.
(b) The branch circuits supply only lighting fixtures that
are equipped with mogul-base screw-shell lampholders or with
l ampholders of other types approved for the purpose.
(c) The fixtures are mounted not less than 8 feet above the
floor.
(d) Integral lighting switch, i f used, shall not be readily
accessible.
Exception No. 2: The voltage shall not exceed 300 volts to
ground on branch circuits in industrial establishments, stores,
health care f a c i l i t i e s , office buildings, schools, or public and
commercial areas of other buildings such as hotels or
transportation terminals where all of the following conditions
are mot.
(a) The branch circuits supply only the ballasts for
electric-discharge lamps mounted in permanently installed
fixtures.
(b) The fixtures do not have manual swi,tch control, as an
integral part of the fixture.
363-14: Accept
CMP 7
SUBMITTER: TSC-Approved for the Purpose
PITOPO-~-~.'125 See the Technical Subcommittee "Recommendations"
un-GB-de
' -~"~Te definition of "Approved for the Purpose" in Article
i00.
SUBSTANTIATION: See the TSC "findings" under the definition of
=Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I
Delete second sentence.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-15: Accept
CMP 7
SUBMITTER: CM
' P7
I PROPOSAL: 125A Insert a period after "raceways" and delete
remalnder of the f i r s t sentence.
SUBSTANTIATION: To comply.with TSC on Approved for the Purpose
reco~ndations.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
132
additions, deletions and moves. Evenwith raised floors two or
more feet above structural (true) floors I t is d i f f i c u l t to get
enough pipe' In an installation to satisfy such needs. Use of
multiple runs of unpunched metal wlreway with hinged metal
covers and side mounted* metal outlet boxes has proved the most
practical way of handling large numbers of branch circuit
conductors in the relatively confined space under raised floors
in f a c i l i t i e s ndt presently subject to the National Electrical
Code. Supporting raceway off the floor minimizes problems
related to d i r t accumulation and accidental water spills.
Inclusion of intermediate metal conduit was made to cover this
newly listed material while metal clad cable appears as useful
as other metallic cable types. ~
*Note: Side mounting of boxes allows horizontal mounting of
receptacles which eliminates d i r t collecting in up-facing
receptacles.
PANEL RECOMMENDATION: Accept as Revised:
Delete "copper-sheathed cable," "aluminum-sheathed cable," the
last sentence, and the exception.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
- \
363-18: Accept
CMP 7
SUBMITTER: TSC-Approved for the Purpose
126 See the Technical Subcommittee "Recommendations"
un--fi-dE~--t'F~e definition of "Approved for the Purpose" in Article
I00.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOYAMENDATION: Accept as Revised:
I Delete "approved for the purpose" and replace with "identified
for the use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-20: Accept
CMP 7
SUBMITTER: TSC-Approvedfor the Purpose
I~ITOI~O~A
' L-~
•. 127 See the Technical Subcommittee "Recon~mendations"
un--n'd-6~-tT~ definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete "approved for the purpose" and replace with "identified
for the'use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 366 -- ELECTRICAL FLOORASSEMBLIES
366-6: Accept
CMP 7
SUBMIITTER: TSC-Nominal Voltage
l l~TOl~S'~-~. 128 Add "nominal" after "120 volts."
~I~%"FA]~TIATION: Change recommended for clarification and to
6btain conformance with present practice and uniformity within
the Code.
PANEL RECOI~MENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
366-20(b)(1): Reject
CMP 7
SUBMITTER: TSC-Nominal Voltage
!MTOI~TSA
' L-T 129 Revise as follows:
rated voltage and current.
SUBSTANTIATION: Changerecommended for clarification and to
obtain conformance with present practice and uniformity within
the Code.
PANELRECOMMENDATION: Reject.
PANEL UOMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
o
645-2(c)(2): Accept
CMP 7
SUBMITTER: R. Bezdegian, Shrewsbury, MA
PRI]PI)~'A~-F: 132 Add "Type AC cable."
~'I]~'~'AI~rIATION: Type AC cable is suitable for this use and is
more readlly obtainable then Type MC. I t is permitted by
Section 300-22(c) above ceilings used for air-handling. Why not
under raised floors. It'could withstand physical injury, much
the same as Type MC, flexible metal conduit, l i q u i d t i g h t .
flexible metal conduit, or data processing equipment cables.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: g.
NEGATIVE: Sappington, Bowen, Hart.
EXPLANATIONOF VOTE:
~APPIRGIDN: I do not feel sufficient supporting comment has
been submitted. I feel there is a real Question relative to
terminations and mechanical execution, therefore, in order to
minimize potential fires resulting from same, said proposal
should not be accepted.
BOWEN: I am voting negative.° I do not feel that under raised
floors is as acceptable as above ceilings. Also the termination
difference.
HART: I do not believe that there is sufficient supporting
• comment to accept this Proposal. Even though there are some
similarities between Type AC cable and those listed in the
"substantiation," there is a considerable difference in the
terminations. I see no need to include Type AC cable in this
section.
645-3: Accept
CMP 7
SUBMITTER: SouthwesternSection IAEI
PKUPU~AL: 133 Change the word "electric" to "electronic data
processing" in Subparagraph (a);
SUBSTANTIATION: There are certain associated functions carried
out in data processing rooms whic~ e~)loy electric typewriters,
adding machines, calculators, etc., and this equipment Js not
part of the data'processing system. Under this present Code
wording, these appliances must be capable of being disconnected
along with the computer equipment. Furthermore; the present
phrase "electric equipment in the room" can include f i r e . warning
systems and f i r e suppression systems. I t appears from the
statements made in NFPA75 dealing with protection of electronic
computers and data processing equipment that the Intent is to
disconnect the electronic equipment rather than other appliances
or systems in the'room. The wording of the Code should reflect
this intent.
PANEL RECOMMENDATION: Accept as Revised:
Replace existing Section 645z3 with the following paragraph:
645-3. Disconnecting Means. A disconnecting means shall be
provided to disconnect the power to all electronic equipment in
the computer room. This disconnecting means shall be controlled
from locations readily accessible t o t h e operator at the
principal exit doors. There shall also be a similar
disconnecting means to disconnect the air-conditioning system
serving this area.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 645 -- DATA PROCESSINGSYSTEMS
645-I: Accept
~P 7
Secretary's Note: I t was the action of the Correlating
Committee that the Panel clarify the Panel Recommendation with
regard to original Proposal.
[
SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn.
I~TOI}~5"AL-~.
• 130 Delete the word "including" and replace with the
~ t h e r
than."
SUBSTANTIATION: There are misinterpretations of this section.
I t is unrealistic and we do not believe i t was the intent of the
Panel to include in the requirements under Section 645-i the
remote telephone terminal units and cash registers in
supermarkets and other similar small terminals.
PANEL RECOMMENDATION: Accept as Revised!
Add the words "in a data p~ocessing,room" at the end of
Section 645-1.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
645-2(c)(2):"
"" - Accept
CMP 7
SUBMITTER: D. C. Smith, Sperry Univac
IMTOI~'IE~.- 131 Revise as follows:
~ e
branch circuit supply conductors to receptacles are
in rigid metal conduit, intermediate metal conduit, electrical
metallic tubing, metal wireway, metal surface raceway with metal
cover, flexible metal conduit, liquidtight flexible metal
conduit, copper-sheathed cable, mineral-insulated metal-sheathed
cable, aluminum-sheathed cable, or metal clad cable. Wireway or
metal surface raceway, when-used, shall be mounted with a
minimum clearance of 1 1/2 inches between the structural (true)
floor and the bottom of the raceway.
Exception: Wireway or metal surface raceway, so long as
wiring method is exposed.
SUBSTANTIATION: Large electronic data processing systems often
require 200 to 600 or occasionally more branch circuit
conductors in a single room. Many such f a c i l i t i e s undergo
frequent changes in EDP hardware with associated branch circuit
645-3(a): Reject
CMP 7
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
I~TOI~S'AL-~. 134 Delete the word "electric" and replace with the
wor--6-F-d-~EFectronic.,
SUBSTANTIATION: There are certain associated functions carried
out in data processing rooms which employ electric typewriters,
adding machines, calculators, etc., and this equipment is not
part of the data processing system. Under this present Code
wording, these appliances must be capable of being disconnected
along with the computer equipment. Furthermore, the present
phrase "electric equipment in the room" can include f i r e wa~ning
systems and f i r e suppression systems. I t appears from the
statements made in NFPA75 dealing with protection of electronic
computers and data processing equipment that the intent is to
133
installations. Maintenance electricians should have sufficient
workspace in front of a wireway that they can look inside and
examine the. condition of conductor insulation for splice
Insulation before pulling wires out of a wireway. Experience
has shown'that conductor's insulation does become damaged and
the insulation on splices can open up Which can present a severe
shock hazard to people who reach into the wiroway while working
"blind". A 12 Inch minimum working space is a reasonable and
practical dimension and will greatly enhance safe working
conditions for maintenance electricians.
PANEL RECOI~MENDATION: Reject.
PANEL COMMENT: Already covered by Section llO-16.
volt uN PANELRECO~WIENDATION: UnanimouslyAffirmative.
364-5, Exception No. 2: Reject
CMP 8
SUBMII"rER: TSC-Approvedfor the Purpose
PROPDSAL: 166 See the Technical Subcommittee "Recammendations"
un--B-d-~-~--tITe definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the clefinitlon of
"Approved for the Purpose" in Article 100.
PANEL RECOf~IENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 165.
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
364-8: Accept
CMP 8
SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.
IPRUPO~AL: 167 Add a sentence as follows:
~ l e
cord assembly connections may be made directly to the
=load end terminals of a busway plug-ln device, providing the
connection includes a suitable tension take-up device on the
cord.
SUBSTANTIATION: Section 364-8 l i s t s eight types of equipment
permitted for connection to busway but contains no guidelines
for the make-up of such connections. In the case of cord
assembly connections to busway plug-in devices, seekers of
guidance may be drawn to 400-7(b). This paragraph is aimed
primarily at fixed location connections and requires a
receptacle outlet on the power supply plus an attachment plug on
the cord.
Minimizes the possibility of unnecessary components being
incorporated in the connection.
PANEL RECO~ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
362-12-(New): Reject
CMP 8
SUBMIl-rER: SouthwesternSection IAEI
162
Position. Wiroways may be installed with the cover
face in a downward position provided suitable supports for
conductors are installed therein at points not more than three
feet apart.
SUBSTANTIATION: in the definition of a wlreway in Section 362-i
appears the statement "inwhich conductors are laid in place
after the wireway has been installed." This implies and has
been interpreted to mean that wireways must be installed with
the cover on the side or top for conductors to be laid in
place. But in many applications, this is an impractical
position. Where conductors have suitable insulating supports,
they can be positioned in a wireway with the cover facing down
without danger of ,damaging the conductor insulation. This
provision has been permitted in the City of Los Angeles for many
years with no reported failures.
PANEL RECOf~4ENDATION: Reject.
PANEL CO,WENT: Such practice is not prohibited by present Code.
VOTE ON PANELRECO~4ENDATION: UnanimouslyAffirmative.
364-8: Accept
CMP
SUBMITTER: H. F. van der Voort, Cleveland, Ohio
~KUPU3AL: 168 Add "rigid nonmetallic conduit" after
~diate,metal
conduit." Then add now sentence at end of
section,to read: "Where rigid nonmetallic conduit is used,
connection of equipment grounding conductors in the rigid
nonmetallic conduit to the wireway shall comply with Sections
250-113 and 250-118."
SUBSTANTIATION: This use of rigid nonmetallic conduit is' now
acceptable under Article 347. The change in Article 364 will
bring i t into conformity with other parts of the Code.
PANEL RECO~V~4ENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-13-(New): Reject
CMP 8
SUBMITTER: SouthwesternSection IAEI
]~TOI~O~TAI--~
•. 163
~3~"~[~-.Working Space. At least 12 inches of working space
shall be provided between the cover of a wiroway and walls,,
ceilings or similar obstructions.
SUBSTANTIATION: The intent of this requirement is to provide a
Safe work environment for electricians wi~o will be performing
maintenance work or making additions to existing wireway
installations. Maintenance electricians should have sufficient
workspace in front of a wiroway that they can look inside and
ekamine the condition of conductor Insulation for splice
insulation before pulling wires out of a wireway. Experience
has shown that conductor's insulatlon does become damaged and
-the insulation on splices can open up which can present a severe
shock hazard to people who reach into the wireway while working
'blind'. A twelve inch minimum working space is a reasonable
and practical dimension and will greatly enhance safe working
conditions for maintenance electricians.
PANEL RECO~ENDATION: Reject.
PANEL COf~ENT: Already covered by Section llO-16.
VOtE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364L12: Reject
CMP 8
SUBMITTER: David J. Snitzer, City of Los Angeles Code Advisory
PROPOSAL: 169 Add note as follows:
~Overcurrent
devices on busways shall be installed in
accordancewith the requirements of Section 380-8.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The cross reference is redundant.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364-12, FPN-(New): Reject
SUBMII-fER: SouthwesternSection IAEI
HRUPU3AL: 170 Fine Print Note.
~rrent
devices on busways shall be installed in
accordance,with the requirements of Section 3~-8.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel Action on Proposal No. 169.
VOTE ON PANELRECOF~IENDATION: UnanimouslyAffirmative.
ARTICLE 364 -- BUSWAYS
364-4(b): Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
I}ITOI~-~.• 164 See the Technical Subcommittee "Reco~nendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "unless specifically approved for the
purpose" and add "unless identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
CMP 8
ARTICLE 365 -- CABLEBUS
365-2: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
HRUPU~AL: 171 See the Technical Subcofm~Ittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and substitute
"identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364-5, Exception No. 1: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
?ITOI~S'AL-~: 165 See the Technical Subcommittee "Reco~vnendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC."findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Revise 364-5 of the NEC as follows: "Buswaysshall be
securely supported at intervals not exceeding 5 feet unless
otherwise designed and marked." Delete Exception Nos. I and 2.
VOTE ON PANEL RECOMI~IENDATION:' Unanimously Affirmative.
365-8: Accept
CMP ,8
SUBMITTER: TSC-Approvedfor the Purpose
]~l~-OIiS-S~i~l~-~•. 172 See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
157
installations. Maintenance electricians should have sufficient
workspace in front of a wireway that they can look inside and
examine the. condition of conductor insulation for splice
Insulation before pulling wires out of a wireway. Experience
has shown'that conductor's insulation does become damaged and
the insulation on splices can open up Which can present a severe
shock hazard to people who reach into the wiroway while working
"blind". A 12 Inch minimum working space is a reasonable and
practical dimension and will greatly enhance safe working
conditions for maintenance electricians.
PANEL RECOI~MENDATION: Reject.
PANEL COMMENT: Already covered by Section llO-16.
volt uN PANELRECO~WIENDATION: UnanimouslyAffirmative.
364-5, Exception No. 2: Reject
CMP 8
SUBMII"rER: TSC-Approvedfor the Purpose
PROPDSAL: 166 See the Technical Subcommittee "Recammendations"
un--B-d-~-~--tITe definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the clefinitlon of
"Approved for the Purpose" in Article 100.
PANEL RECOf~IENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 165.
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
364-8: Accept
CMP 8
SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.
IPRUPO~AL: 167 Add a sentence as follows:
~ l e
cord assembly connections may be made directly to the
=load end terminals of a busway plug-ln device, providing the
connection includes a suitable tension take-up device on the
cord.
SUBSTANTIATION: Section 364-8 l i s t s eight types of equipment
permitted for connection to busway but contains no guidelines
for the make-up of such connections. In the case of cord
assembly connections to busway plug-in devices, seekers of
guidance may be drawn to 400-7(b). This paragraph is aimed
primarily at fixed location connections and requires a
receptacle outlet on the power supply plus an attachment plug on
the cord.
Minimizes the possibility of unnecessary components being
incorporated in the connection.
PANEL RECO~ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
362-12-(New): Reject
CMP 8
SUBMIl-rER: SouthwesternSection IAEI
162
Position. Wiroways may be installed with the cover
face in a downward position provided suitable supports for
conductors are installed therein at points not more than three
feet apart.
SUBSTANTIATION: in the definition of a wlreway in Section 362-i
appears the statement "inwhich conductors are laid in place
after the wireway has been installed." This implies and has
been interpreted to mean that wireways must be installed with
the cover on the side or top for conductors to be laid in
place. But in many applications, this is an impractical
position. Where conductors have suitable insulating supports,
they can be positioned in a wireway with the cover facing down
without danger of ,damaging the conductor insulation. This
provision has been permitted in the City of Los Angeles for many
years with no reported failures.
PANEL RECOf~4ENDATION: Reject.
PANEL CO,WENT: Such practice is not prohibited by present Code.
VOTE ON PANELRECO~4ENDATION: UnanimouslyAffirmative.
364-8: Accept
CMP
SUBMITTER: H. F. van der Voort, Cleveland, Ohio
~KUPU3AL: 168 Add "rigid nonmetallic conduit" after
~diate,metal
conduit." Then add now sentence at end of
section,to read: "Where rigid nonmetallic conduit is used,
connection of equipment grounding conductors in the rigid
nonmetallic conduit to the wireway shall comply with Sections
250-113 and 250-118."
SUBSTANTIATION: This use of rigid nonmetallic conduit is' now
acceptable under Article 347. The change in Article 364 will
bring i t into conformity with other parts of the Code.
PANEL RECO~V~4ENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
362-13-(New): Reject
CMP 8
SUBMITTER: SouthwesternSection IAEI
]~TOI~O~TAI--~
•. 163
~3~"~[~-.Working Space. At least 12 inches of working space
shall be provided between the cover of a wiroway and walls,,
ceilings or similar obstructions.
SUBSTANTIATION: The intent of this requirement is to provide a
Safe work environment for electricians wi~o will be performing
maintenance work or making additions to existing wireway
installations. Maintenance electricians should have sufficient
workspace in front of a wiroway that they can look inside and
ekamine the condition of conductor Insulation for splice
insulation before pulling wires out of a wireway. Experience
has shown that conductor's insulatlon does become damaged and
-the insulation on splices can open up which can present a severe
shock hazard to people who reach into the wireway while working
'blind'. A twelve inch minimum working space is a reasonable
and practical dimension and will greatly enhance safe working
conditions for maintenance electricians.
PANEL RECO~ENDATION: Reject.
PANEL COf~ENT: Already covered by Section llO-16.
VOtE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364L12: Reject
CMP 8
SUBMITTER: David J. Snitzer, City of Los Angeles Code Advisory
PROPOSAL: 169 Add note as follows:
~Overcurrent
devices on busways shall be installed in
accordancewith the requirements of Section 380-8.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The cross reference is redundant.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364-12, FPN-(New): Reject
SUBMII-fER: SouthwesternSection IAEI
HRUPU3AL: 170 Fine Print Note.
~rrent
devices on busways shall be installed in
accordance,with the requirements of Section 3~-8.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel Action on Proposal No. 169.
VOTE ON PANELRECOF~IENDATION: UnanimouslyAffirmative.
ARTICLE 364 -- BUSWAYS
364-4(b): Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
I}ITOI~-~.• 164 See the Technical Subcommittee "Reco~nendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "unless specifically approved for the
purpose" and add "unless identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
CMP 8
ARTICLE 365 -- CABLEBUS
365-2: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
HRUPU~AL: 171 See the Technical Subcofm~Ittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and substitute
"identified for such use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
364-5, Exception No. 1: Accept
CMP 8
SUBMITTER: TSC-Approvedfor the Purpose
?ITOI~S'AL-~: 165 See the Technical Subcommittee "Reco~vnendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC."findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Revise 364-5 of the NEC as follows: "Buswaysshall be
securely supported at intervals not exceeding 5 feet unless
otherwise designed and marked." Delete Exception Nos. I and 2.
VOTE ON PANEL RECOMI~IENDATION:' Unanimously Affirmative.
365-8: Accept
CMP ,8
SUBMITTER: TSC-Approvedfor the Purpose
]~l~-OIiS-S~i~l~-~•. 172 See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
157
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "approved for the purpose" and add the word
"Approved" at the the beginning of the sentence.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Chapter 9 Table l, Note 5: Accept
CMP 8
SUBMITTER! CMP 8
!aITOPOS7
' ~-~•. 175A Add to Note 5 the word "maximum" before
~ e . "
Add FPN after Note 5 to read:
Table l is based on common conditions of proper cabling and
alignment of conductors where the length of the pull and the
number of bends are within reasonable limits. I t should be
recognized that for unusual conditions a larger size conduit or
a lesser conduit f i l l should be considered.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 374 -- AUXILIARY GUTTERS
374-9(f)-(New): Reject
CMP 8
SUBMITTER: S. D. Mauney, Carolina Power & Light Company
PHUPU~AL: 173 Add new (f) as follows:
-~here
an auxiliary gutter is to contain bends or taps to
an electric supplier's service conductors larger than No. i AWG,
its width at the cover shall be at least 200 percent of that
given in Table 373-6(a) and its minimum depth from cover to back
shall be 100 percent of the width given in Table 373-6(a).
Where the size of the supplier's service conductors is not
readily available, the conductor size may be calculated as the
equivalent size of the largest aluminum conductors with a 75°C
ampacity rating equal to the sum of the service overcurrent
devices tapped to the supplier's service conductors. In the
table, "Wires per terminal" is to be used to indicate the number
of the supply service conductors in parallel per phase.
SUBSTANTIATION The required width of the auxiliary gutters used
on surv~ces for taps to several or more meter or service
equip(nent cabinets is inadequate dn many instances. No stated
minmum depth is required. Due to the stiffness and size of the
service conductors and to the large size of taped connectors,
the connections are under pressure from adjacent conductors,
connectors, and the gutter cover.
Even the best tapes are subject to abrasion due to expansion
and contraction of the conductors with the load cycle. They
also soften due to heat. Shorts occur when the tape is abraded
away or softened abnormally. More space will help connections
to be positioned away from each other and from the cover. The
proposed size is minimum. Experience may indicate that larger
sizes may be needed.
More space is also needed as/additional taps are made to the
service conductors. This is ~specially true of commercial
buildings with movable walls where the number, size, and loads
of the occupancies is ever changing. Space is also needed when
loads are checked with cllp-on ammeters, etc.
Increasing the size of service gutters is already often done
by some electricians Who realize that the savings in
installation labor and maintenance easily offset the additional
material cost involved.
Safety is involved anytime a f i l l e d gutter is opened for
inspection or to make changes as removing the cover allows the
spring action of the cramped
conductors to come into play. Closing the cover puts additional
pressure on the connections.
PANEL RECOI~4ENDATION: Reject.
PANEL COMMENT: Already covered by Section 374-9(d). Training
space is being studied by Panel 9.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Table l , Chapter g: Reject
CMP 8
SUBMITTER: CMP 8
175B In the 3 conductor column, delete 40 (percent
~ d
insert 33 (percent f i l l ) for both lead covered and
non-lead covered conductors.
SUBSTANTIATION: There exists a l ~ t t l e understood problem of
"jam ratio" where only three conductors are installed in a
conduit. This is ratio of the diameters of the conduit and the
single conductor (D/d). This ratio is c r i t i c a l between 2.5 and
3.0 where the conductors are not triplexed. At a ratio of 3.0
and greater, the conduit is wider than the sum of the 3'
conductors which prevents Jamming.
At this ratio the area of the conductors is 3d2~
The area of the conduit is (3d)2 = 9d2~
L
~
---I-F i l l = 3/9 = 33 1/3 percent.
At 40 percent f i l l the maximum allowable conductors are always
in the c r i t i c a l Jam ratio.
PANEL REC~NDATION: Reject.
PANtL ~UMM~NI: UMP ~ would prefer to withdraw the Proposal and
I t is rejected on that basis.
VOTE ON PANEL RECOMMENDATION: Unanimously A f f i r m a t i v e . .
CMP 8
Chapter 9, Table l , Note 6: Reject
SUBMITTER: CMP 8
PROPOSAL: I75C Add a new Note 6 as follows:
~ i l l
shall be permitted for triplexed conductors."
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel Comment on Proposal No. 175B.
VOTE ON PANELRECOI¢MENDATION: Unanimously Affirmative.
Table 1, Chapter 9: Reject
CMP 8
SUBMITTER: Joseph M. Ostrlhonsky, Sioux City, IA
PROPOSAL:,176 I suggest that the number of wires that is
a-lT6~--d-in 1/2 inch and 3/4 inch pipe be reduced to half. The
wire I'm talking about is TW, THHN, THWN, sizes #12, #14, and
#10. As an alternate, they would change the 40 percent f i l l to
60 percent f i l l based on individual diameters.
SUBSTANTIATION: I f you have had any experience at a l l , you will
know that is I t very d i f f l c u l t to pull, say 9-12 inch TW wires
into a piece of 1/2 inch conduit. I t is almost impossible i f
you havetwo go° bends in the conduit. This Js why I think they
should reduce the number of wires or else change the percent
f i l l of the conduit.
PANEL RECOMMENDATION: Reject.
PANEL CL)f~ENI: ine "conduit f i l l tables are based on the concept
that a safe practical.conduit f i l l percentage is one in which
the diameter of a circle circumscribed around the assembled
conductors would approximate 75 percent of the conduit
diameter. The net area of the conductors within this
theoretical circle approximates 40 percent f i l l .
The Code establishes a 40 percent maximum conduit f i l l .
The
Code also establishes a maximum of four quarter bends (360
degrees t o t a l ) . The Code does not establish a maximum length of
pull. The allowable length of a pull is contingent on a number
of factors including but not limited to: I) maximum allowable
conductor tension, 2) the plane of the bends (whether they are
horizontal or vertical and whether any are reverse bends), 3)
proper cabling of the conductors, 4) the weight of the cable, 5)
the coefflcent of f r i c t i o n between the conductors and the
conduit, and 6) sidewall pressure.
Since the Code is not a design manual Judgement must be used
in studying all of these "factors on whether.to use the maximum
f i l l and the maximum number of bends to accommodate the maximum
length of pull. Proper cabling of a large number of conductors
is of extreme importance in such a Judge~nt.
VOTE ON PANELRECOI~ENDATION: UnanimouslyAffirmative.
CHAPTER 9 -- TABLES AND EXAMPLES
Chapter 9, A. Tables, Note 2: Reject
CMP 8
SUBMITTER: Peter Pollak, The Aluminum Association
I~OFOSAL-~. 174 In the second sentence of Note 2, replace
~-~ted
or bare)" with "(insulated, bare or compact)."
SUBSTANTIATION: Question arises in the f i e l d regarding the
selection of the proper conduit size for the application.
Makes clearer the fact that the actual dimensions of compact
equipment grounding conductor shall be used in the calculation
of conduit f i l l .
PANEL RECOI~4ENDATION: Reject.
PANEL COMMENT: Proposal is pcimarily a design consideration.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Durham.
EXPLANATION OF VOTE:
DURflAM: Panel action is not consistent with Proposal No. 175.
Chapter 9., A. Tables, Note 4: Accept
CMP 8
SUBMITTER: Peter Po'llak, The Aluminum Association
Ii PRUPU~AL 175 In Note 4 insert "such as compact
or
=
~ductor
cables," after "Chapter 9 . '
' SUBSTANTIATION: Question arises in the f i e l d regarding the
selection of the proper conduit size for the application.
Makes clear the fact that actual dimensions of compact or
multlconductor cables shall be used in the calculation of
condu'i t f i l l .
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
158
additions, deletions and moves. Evenwith raised floors two or
more feet above structural (true) floors I t is d i f f i c u l t to get
enough pipe' In an installation to satisfy such needs. Use of
multiple runs of unpunched metal wlreway with hinged metal
covers and side mounted* metal outlet boxes has proved the most
practical way of handling large numbers of branch circuit
conductors in the relatively confined space under raised floors
in f a c i l i t i e s ndt presently subject to the National Electrical
Code. Supporting raceway off the floor minimizes problems
related to d i r t accumulation and accidental water spills.
Inclusion of intermediate metal conduit was made to cover this
newly listed material while metal clad cable appears as useful
as other metallic cable types. ~
*Note: Side mounting of boxes allows horizontal mounting of
receptacles which eliminates d i r t collecting in up-facing
receptacles.
PANEL RECOMMENDATION: Accept as Revised:
Delete "copper-sheathed cable," "aluminum-sheathed cable," the
last sentence, and the exception.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
- \
363-18: Accept
CMP 7
SUBMITTER: TSC-Approved for the Purpose
126 See the Technical Subcommittee "Recommendations"
un--fi-dE~--t'F~e definition of "Approved for the Purpose" in Article
I00.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOYAMENDATION: Accept as Revised:
I Delete "approved for the purpose" and replace with "identified
for the use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
363-20: Accept
CMP 7
SUBMITTER: TSC-Approvedfor the Purpose
I~ITOI~O~A
' L-~
•. 127 See the Technical Subcommittee "Recon~mendations"
un--n'd-6~-tT~ definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete "approved for the purpose" and replace with "identified
for the'use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 366 -- ELECTRICAL FLOORASSEMBLIES
366-6: Accept
CMP 7
SUBMIITTER: TSC-Nominal Voltage
l l~TOl~S'~-~. 128 Add "nominal" after "120 volts."
~I~%"FA]~TIATION: Change recommended for clarification and to
6btain conformance with present practice and uniformity within
the Code.
PANEL RECOI~MENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
366-20(b)(1): Reject
CMP 7
SUBMITTER: TSC-Nominal Voltage
!MTOI~TSA
' L-T 129 Revise as follows:
rated voltage and current.
SUBSTANTIATION: Changerecommended for clarification and to
obtain conformance with present practice and uniformity within
the Code.
PANELRECOMMENDATION: Reject.
PANEL UOMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
o
645-2(c)(2): Accept
CMP 7
SUBMITTER: R. Bezdegian, Shrewsbury, MA
PRI]PI)~'A~-F: 132 Add "Type AC cable."
~'I]~'~'AI~rIATION: Type AC cable is suitable for this use and is
more readlly obtainable then Type MC. I t is permitted by
Section 300-22(c) above ceilings used for air-handling. Why not
under raised floors. It'could withstand physical injury, much
the same as Type MC, flexible metal conduit, l i q u i d t i g h t .
flexible metal conduit, or data processing equipment cables.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: g.
NEGATIVE: Sappington, Bowen, Hart.
EXPLANATIONOF VOTE:
~APPIRGIDN: I do not feel sufficient supporting comment has
been submitted. I feel there is a real Question relative to
terminations and mechanical execution, therefore, in order to
minimize potential fires resulting from same, said proposal
should not be accepted.
BOWEN: I am voting negative.° I do not feel that under raised
floors is as acceptable as above ceilings. Also the termination
difference.
HART: I do not believe that there is sufficient supporting
• comment to accept this Proposal. Even though there are some
similarities between Type AC cable and those listed in the
"substantiation," there is a considerable difference in the
terminations. I see no need to include Type AC cable in this
section.
645-3: Accept
CMP 7
SUBMITTER: SouthwesternSection IAEI
PKUPU~AL: 133 Change the word "electric" to "electronic data
processing" in Subparagraph (a);
SUBSTANTIATION: There are certain associated functions carried
out in data processing rooms whic~ e~)loy electric typewriters,
adding machines, calculators, etc., and this equipment Js not
part of the data'processing system. Under this present Code
wording, these appliances must be capable of being disconnected
along with the computer equipment. Furthermore; the present
phrase "electric equipment in the room" can include f i r e . warning
systems and f i r e suppression systems. I t appears from the
statements made in NFPA75 dealing with protection of electronic
computers and data processing equipment that the Intent is to
disconnect the electronic equipment rather than other appliances
or systems in the'room. The wording of the Code should reflect
this intent.
PANEL RECOMMENDATION: Accept as Revised:
Replace existing Section 645z3 with the following paragraph:
645-3. Disconnecting Means. A disconnecting means shall be
provided to disconnect the power to all electronic equipment in
the computer room. This disconnecting means shall be controlled
from locations readily accessible t o t h e operator at the
principal exit doors. There shall also be a similar
disconnecting means to disconnect the air-conditioning system
serving this area.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 645 -- DATA PROCESSINGSYSTEMS
645-I: Accept
~P 7
Secretary's Note: I t was the action of the Correlating
Committee that the Panel clarify the Panel Recommendation with
regard to original Proposal.
[
SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn.
I~TOI}~5"AL-~.
• 130 Delete the word "including" and replace with the
~ t h e r
than."
SUBSTANTIATION: There are misinterpretations of this section.
I t is unrealistic and we do not believe i t was the intent of the
Panel to include in the requirements under Section 645-i the
remote telephone terminal units and cash registers in
supermarkets and other similar small terminals.
PANEL RECOMMENDATION: Accept as Revised!
Add the words "in a data p~ocessing,room" at the end of
Section 645-1.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
645-2(c)(2):"
"" - Accept
CMP 7
SUBMITTER: D. C. Smith, Sperry Univac
IMTOI~'IE~.- 131 Revise as follows:
~ e
branch circuit supply conductors to receptacles are
in rigid metal conduit, intermediate metal conduit, electrical
metallic tubing, metal wireway, metal surface raceway with metal
cover, flexible metal conduit, liquidtight flexible metal
conduit, copper-sheathed cable, mineral-insulated metal-sheathed
cable, aluminum-sheathed cable, or metal clad cable. Wireway or
metal surface raceway, when-used, shall be mounted with a
minimum clearance of 1 1/2 inches between the structural (true)
floor and the bottom of the raceway.
Exception: Wireway or metal surface raceway, so long as
wiring method is exposed.
SUBSTANTIATION: Large electronic data processing systems often
require 200 to 600 or occasionally more branch circuit
conductors in a single room. Many such f a c i l i t i e s undergo
frequent changes in EDP hardware with associated branch circuit
645-3(a): Reject
CMP 7
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
I~TOI~S'AL-~. 134 Delete the word "electric" and replace with the
wor--6-F-d-~EFectronic.,
SUBSTANTIATION: There are certain associated functions carried
out in data processing rooms which employ electric typewriters,
adding machines, calculators, etc., and this equipment is not
part of the data processing system. Under this present Code
wording, these appliances must be capable of being disconnected
along with the computer equipment. Furthermore, the present
phrase "electric equipment in the room" can include f i r e wa~ning
systems and f i r e suppression systems. I t appears from the
statements made in NFPA75 dealing with protection of electronic
computers and data processing equipment that the intent is to
133
REPORT OF CODE-MAKINGPANEL NO. 9
paragraph as presently written covers only nonmetallic boxes
less than 100 cubic inches. The second paragraph as presently
written covers nonmetallic boxes over 100 cubic inches
manufactured with bonding means,
i
The proposed wording should add c l a r i t y to this section. The
word UException" is needed in the second paragraph because
"only" is contained in the f i r s t , paragraph.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CI~° agrees with the intent of the Proposal see
action on Proposal No. 3.
VOTE ON PANELRECOI~IENDATION: UnanimouslyAffirmative;
ARTICLE 370 -- OUTLET, SWITCH AND JUNCTION
BOXES, AND FITTINGS
370-3: Reject
~
CMP 9
SUBMITTER: R. W. Eckardt, Underwriters Laboratories Inc.
I
Reviseas follows:
~Nonmetallic
Boxes. Nonmetallic boxes shall be permitted
only with open wiring on insulators, concealedknob and tube
wiring, nonmetallic-sheathed cable and with rigid nonmetallic
conduit.
Exception: Nonmetallic boxes over lO0 cubic inches
manufactured with bonding means between all raceway and cable
entries shall be permitted to be used with metal raceways and
metal-sheathed cable.
SUBSTANTIATION: The wording adopted for the Ig78 Code
inadvertently emitted covering nonmetallic boxes over I00 cu.
in. with rigid nonmetallic conduit. This error can be corrected
by omitting the phrase "not over lO0 cu. in." in the f i r s t
sentence and making the second sentence an "Exception."
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 3.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
f
370-4: Reject
CMP 9
SUBMITTER: Allen KnicKrehm, Los Angeles Chapter, NECA
]~)'I)O-S~L-~.'5
A means shall be provided in each metallic box,
~ i t
is a pressed steel or a cast material type, for the
connection of an equipment grounding Conductor.
SUBSTANTIATION: Nonmetallic raceway and nonmetallic cable
systems using equipment grounding conductors require the
connection of such conductors to metallic boxes.
The connections of grounding conductors where a means is not
provided for the connections usually results in a hole and a
nut-and-bolt situation which may void the listing of the box,
destroy its concrete or llquidtight integrity. Therefore i t is
f e l t that a grounding lug connection should be provided for the
equipment grounding conductors.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 5A.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-3: Reject
CMP 9
SUBMITTER: R. C. Medley, Square D Co.
PROPOSAL: 2
In the f i r s t paragraph, delete the words "not
over I-O-Ocubic inches."
In the second paragraph, delete the words "over 100 cubic
inches."
SUBSTANTIATION: The volumetric limitations impose unnecessary
restrictions to the usage and applications of nonmetallic
boxes. The f i r s t paragraph describes normal usage. I t is
irrelevant to state volumetric limits. The second paragraph
permits usage with metallic connections provided suitable
bonding is included. Again, volumetric restriction is not
significant to usage.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Nonmetallic boxes less than 100 cu. inches are
not suitable for use with all wiring methods.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
CRAMER: In our Panel discussions, pushbutton devices in
nonmetallic boxes (pushbutton stations) smaller than 100 cubic
inches wece discussed. Pushbutton ~tations are not covered
under Article 370 and consequently this Section does not
preclude the use of such a nonmetallic station with metal
raceways.
370-20(d): Accept
CMP 9
SUBMITTER: CI~° g
]}]TOIsO-~-A-C-~". 5A
Add a new section 370-20(d) as follows:
~ s
shall be provided in each metallic box, designed for
use with nonmetallic raceways and nonmetallic cable systems, for
the connection of an equipment grounding conductor.
SUBSTANTIATION: We agree with the intent of Propdsal No. 5, but
think this wording is better.
PANEL RECOMMENDATION: Accept as Revised:
Add t i t l e to section "(d) Grounding Provisions. N
Change "metallic" to "metal" box to remain consistent with
remaining portions of Section 370-20.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-5: Accept
.
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
I~TOI~)-S'AL-~. 6
See the Technical Subcommittee "Recommendations"
~the
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATIONI See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOIIMENDATION: Accept as Revised:
Delete the words "shall be approved for the purpose" and add
the words "shall be listed for use in wet locations."
VOTE ON PANELRECOI~MENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Cramer.
EXPLANATION OF VOTE:
CRAMER: "Listed" boxes in the size desired are not always
available. Field fabrication or modification is sometimes
required. Consequently the box cannot be listed. Remove
"approved for the purpose" and replace with "suitable for the
environment."
370-3: Accept
CMP 9
SUBMII-TER: J.J. Kark, National Electrical Manufacturers
PROPOSAL: 3
D e l e t ethe words "not over 100 cubic inches" from
~ t
paragraph of 370-3. Add the word "also" after "shall"
in the second sentence.
The recommended text would read:
370-3. Nonmetallic Boxes. Nonmetallic boxes shall be permitted
only with open wiring on insulators, concealed knob-and-tube
wiring, nonmetallic-sheathed cable, and with rigid nonmetallic
conduit.
Nonmetallic boxes over 100 cubic inches manufactured with
bonding means between all raceways and cable entries shall also
be permitted to be used with metal raceways and metal-sheathed
cable.
SUBSTANTIATION: Neededfor clarification. The wording "not
over 100 cubic inch volume" is unnecessarily restrictive.
The word "also" would c l a r i f y this as an additional permitted
370-6(a) & Table 370-6(a): Reject
CMP 9
SUBMITTER: Paul DeMuth, Sheldon, IA
I~IOFO3XZT 7
~'~o--be added to Table 370-6(a) between line 18 and line 19:
4 I / 8 x 2 3/8 x 2 1/8
Device 18.0
g 8 7 60
use.
PANEL RECOMMENDATION: Accept as Revised:
Add the words "In addition thereto" before the word
"Nonmetallic" in the second sentence.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Barker.
EXPLANATION OF VOTE:
BARKER: All nonmetallic boxes over 100 cubic inches should
have bonding means to prevent misapplication in the field with
metal conduit. The alternate would be to prohibit the use of
metal conduit. Grounding is an essential safety requirement.
t.
B. To be added after Section 370-6(a) with the current Section
370-6(a)(2) to follow as 370-6(a) 3:
(2) Where used, with oversized devices (dimmers,
photo-cells, etcL) freespace in addition to
that required in Section 370-6(a)(1) shall be
adequately provided for.
SUBSTANTIATION:
A. The 4 1/8 x 2 3/8 x 2 1/8 de~ice box is often needed for
surface work requiring 3/4 inch and larger conduit for Junction
and outlet boxes. As such i t should be added to the listing of
metallic boxes in B. When applying standard box f i l l methods to
the use of some larger devices, i t has been found that planned
boxes are often too small to properly provide required free
space. By the addition of a new section to point out potential
problems in this c r i t i c a l area, errors in freespace planning
may be avoided.
PANEL RECOMMENDATION: Reject.
370~3: Reject
CMP 9
SUBMITTER: Donald W. Cremer, St. Louis, MO
4
In the f i r s t paragraph, eliminate "not over 100
~ches."
In the second paragraph, add "Exception" prior to the f i r s t
word of the paragraph.
SUBSTANTIATION: Wording is intended to c l a r i f y only. Present
wording does not cover nonmetallic boxes over I00 cubic inches
that are not manufactured with bonding means. The f i r s t
k
160
,
PANEL COMMENT: (a) The table does not preclude the use of this
box. While we recognize this is a commonly used box, i t is not
necessary to include i t in Table 370-6(a) as a standard box. (b)
I t is unenforceable.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-6(c), Exception-(New): Reject
CMP 9
SUBMITTER: Roger C. Troupe, Fremont, NB
FRO
' IB~)-S-A-L-~. 12 Amendby adding exception to read:
---E'R'E'epCion: Conduit bodies having two entries shall be
permitted to have wire to wire splices, for the connection of
utilization equipment leads (Including switching devices) where
thls equipment does not have connection space provided in i t or
for the connections required to change from a conduit wiring
method to a single cord method as allowed by Article 400, where
the f i l l will not exceed 75 percent at any cross-sectlon.
SUBSTANTIATION: NFPANo. 70-PR78'contained nine proposed
revisions in regard to Section 370-6(c), the one being accepted
that of CI~° g. Although some clarification was made, one of the
main objectives sought In the other eight proposals (the
allowability of splicing cords and leads of utilization
equipment where connection boxes are not provided in conduit
bodies with two entries) was s t i l l not achieved. I f i t can be
interpreted that splicing conductors in conduit bodies with only
two entries is allowable under the provisions of section (b),
(even though section (b) opens with its reference being to boxes
100 cu. in. or less, conduit bodies having provision for more
than two conduit entries, and nonmetallic boxes) when section
(b) is refer~ed to by section (c), then the necessary
~llowability for splices and taps in all conduit bodies has been
provided for. However, i t is ' s t i l l virtually impossible to use
standard conduit bodies sized the same as the conduit, where the
conduit is sized properly in accordance with the conductor size
and s t i l l f i t within the scope of Section 370-6(b).
Where cords or the attachment leads of utilization equipment
(including switching devices) are spliced in a conduit body, the
danger of damage to the conductors due to lesser space than
required in Section 370-6(b) is minimized 6ecause of the greater
degree of f l e x i b i l i t y of the cord or equipment leads due t 9
either their being stranded, or being smaller in size, or both.
(Note: Table 370-6(b) does not specify conductors smaller than
No. 14.)
Because these connections can be facilitated safely i f
cross-section f i l l is limited to 75 percent, and because space
about equipment is not always adequate to install a box or
conduit body of adequate size as required by Section 370-6(b),
there is a very definite need for the provisions of this
exception.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered. The
present wording, adequately reflects the Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
CRAMER: I disagree with the need for an exception for a two
entry conduit body but feel that the requirements for two or
mere entry conduit bodies need clarity.
Splicing is now allowable in two entry conduit bodies but
sizing requirements imposed by Section 370-6(b) are d i f f i c u l t to
follow. I don't feel the subject is clearly covered. We should'
relocate t o Section 370-6(c) all requirements pertaining to
conduit bodies and therein locate requirements pertaining to
splices, taps and wires passing through the conduit body.
Table 370-6(a): Reject
CMP g
SUBMITTER: NormanB. Cooney, Parma, Ohio
8
Delete3 x 2 x 1 I/2 device box.
~IATION:
All of these boxes contain cable clamps and
flush devices. Deducting two conductors or even one conductor
makes i t impossible to use this slze box for wiring wlth 12/2 or
14/2 N.M. cable w/grnd.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is notpersuasive as to
necessity. The Panel does not agree with the supporting comment.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-6(a)(1): Accept
CMP 9
SUBMITTER: William E. Slater, RACOInc.
PROPOSAL: 9
Revise last sentence and add new sentence as
The volume of a wiring enclosure (box) shall be the total
volume of the assembled sections, and where used, the space
provided by plaster rings, domed covers, etc., that are marked
with th'eir volume in cubic inches, and extension rings. The
volume of extension rings shall be considered equal to the
volumes shown in Table 370-6(a), for its cemparable box
dimensions, unless marked with a greater volume.
SUBSTANTIATION: Extension rings are basic boxes with the major
portion of the bottom removed and some means provided for
attachment to a box. The basic boxes, that are .listed in Table
370-6(a) are-generally used in manufacturing extension rings,
but volume is not significantly increased by merely renw)ving the
bottom of a box, therefore, additional conductor space is not
provided.
PANEL RECOMMENDATION: Accept as Revised:
I Revise paragraph 370-6(a)(I) of the 1978 NEC as follows: add
the words to the last sentence "inches, or are made from boxes
the dimensions of which are listed in Table 370-6(a)."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-6(a)(1): Accept
CMP 9
SUBMITTER: Kirk Jervik, Sheldon, IA
10 Revise the second sentence as follows:
Where one or more of each of the following fixture studs,
cable clamps, or hickeys are contained In the box, the number of
conductors shall be one less than shown on the tables.
SUBSTANTIATION: The problem lies in that there seems to be some
confusion, to myself and others I've been associated with, as to
whether the intent and purpose of the article is to make one
deduction and only one, whether the box contains Just cable
clamps; Just fixture studs; Just hickeys, or all three. I
firmly believe that with my proposal i t will c l a r i f y the fact
that a deduction will be made when the box contains one of the
above mentioned, a box containing two of the above mentioned
will have two dedbctions, and a box with all three deductions.
For example, a box containing two cable clamps and a f i x t u r e
"stud will have two deductions. One will be made for the cable
clan~)s and one for the fixture stud.
PANEL RECOMMENDATION: Accept as Revised:
Revise second sentence as follows: Where one or mere of these
types of devices, such as fixture studs, cable clamps, or
hickeys are contained in the box, the number of conductors shown
in the table shall be reduced by one for each type of device; an
additional deduction of one conductor shall be made for each
strap containing one or mere devices; and a further deduction of
one conductor shall be made for one or mere grounding conductors
entering the box.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
370-7(c): Reject
Cl~D 9
SUBMITTER: Dale R. Deming, RACO, Inc.
13 Revise as follows:
~onmetallic
Boxes. Where nonmetallic boxes are used with
open wiring or concealed knob-and-tube wiring, the conductors
shall enter the box through individual holes. Where flexible
tubing is used to encase these conductors, the tubing shall
extend from the last insulating support to no less than 1/4-inch
inside the box.
(2) Where nonmetallic sheathed cable is used with boxes which
accept only one strap, containing one or more devices, and with
boxes mounted in ceilings that do not contain devices and where
the cable is fastened within eight inches of these boxes~
measured along the sheath, and the sheath extends into the box
no less than 1/4-inch, securing the cable assc~nbly to the box
shall not be required. In all other instances, the cable
assembly shall be secured to nonmetallic boxes.
SUBSTANTIATION: Considerable confusion has resulted from the
terminology used in the present Code. Reference to single gang
boxes does not indicate which specific types of boxes shall
require some means of securing the cable to the box. Also, in
combining the requirements for nonmetallic sheathed cable with
open wiring and concealed knob-and-tube wiring methods, present
wording indicates that individual conductors and cables shall be
secured when using nonmetallic sheathed cBble. This was not the
intent of C~ No. 9 in accepting the proposal. The reference to
individual conductors is to apply only to open wiring and
concealed knob-and-tube wiring.
This proposal, while not changing intent, clearly defines
those applications in which securing the cable to t~e box is
required and i t more properly states the cable assembly, thus
eliminating the confusion of individual conductors within a
cable assembly.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 13A. Present
requirement is necessary.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
370-6(a)(1): Reject
CMP 9
SUBMITTER: NormanB. Cooney, Parma, Ohio
11 In second sentence after "for", delete "one or
more grounding conductors" and substitute "any."
SUBSTANTIATION: I t is a physical impossibility to install 2
switches on a 2-gang N.M. box that is 45 cu. in. and contains
3-12/3 and 4-12/2 N.M. cables. Those 6 grounding conductors
that are not counted s t i l l reduce the cubic inch capacity of the
box and when the combinations are 1-12/3 and 7-12/2, the
conductors stick out of the box 1/2 inch. Now instead of 6
grounding conductors we have 7.
These cables must come into the box from the top and bottem
and all the knock-outs are used so the grounding conductors must
traverse diagonally as well as horizontally and vertically.
The end result is not only unsafe, but i t is impossible to
terminate flush devices in the box.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent. I f a larger box is needed the Code permits its
use.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
161
370-7(c): Accept
CMP 9
SUBMITTER:. C/iP 9
PROPOSAL: 13A
Delete the last sentence and add the
t'oTFow-i~ng: "In all other instances, (1) cables and (2)
individual conductors of open wiring and concealed knob and tube
wiring, including the flexible tubing i f used, shall be secured
to nonmetallic boxes. Metal raceways, nonmetallic conduit, or
metal-sheathed cable shall be secured to nonmetallic boxes.
SUBSTANTIATION: Clarification for f i r s t sentence. Second
sentence was inadvertently l e f t out of the 1978 NEC.
PANEL RECOMMENDATION: Accept as Revised:
Revise last sentence of 370-7(c) to read: "In all other
instances all permitted wiring methods shall be secured to the
boxes."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Leiman.
EXPLANATION OF VOTE:
LEIMAN: . I agree with the supporting comment. In my personal
experience and discussions with other inspectors, I have found
that the cable sheath has been pulled out of single gang boxes.
370-7(c): Reject
CMP 9
SUBMITTER: Rudolph V. Jones, Virginia Chapter,. IAEI
PI~O]~O-{JJ~-~•. 18 Delete the words "with single gang boxes" in the
~6u-r-t-h--sentence.
SUBSTANTIATION: The requirement for the securing of
nonmetallic-sheathed cables to other than single gang boxes is
not warranted and results in an unnecessary additional expense.
I f i t can be considered safe that nonmetallic-sheathed cable
need not be secured to single gang boxes when fastened within 8
inches of the box measured along the sheath, the application of
such to multi-gang boxes should also be just as safe. The last
sentence specifically requires that cables be secured to the
multi-gang box where the cables are not fastened within 8 inches
of the box measured along the sheath. Unnecessary cl~mps result
in a decrease in volume and work space in the box and increase
the possibility of damage to the cables.
PANEL RECOI~MENDATION: Reject.
PANEL COMMENT: Present require~lent is necessary. See Proposal
No. 13A.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
370-7(c): Reject
CMP 9
SUBMITTER: R. C. Medley, Square D Co.
14
In the fourth sentence, delete the words "is used
~ g l e
gang boxes and where the cable."
SUBSTANTIATION: The paragraph limits usage.to single gang boxes
for which there is no.definition. Entry of multiplecables may
be accomplished by securing cables within eight inches
independent of box style description.
PANEL RECO/~iENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 13A. Present
requirement is necessary.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-7(c)~ Reject
CMP 9
SUBMITTER: J.a. Kark, National Electrical Manufacturers
~ o n
PROPOSAL: 15 Revise fourth sentence to read:
~-er-e nonmetallic-sheathed cable is used with boxes which
accept only one strap containing one or more devices and wlth
boxes mounted in ceilings which ,are for the support of a
f i x t u r e , and where the cable is fastened within 8 inches of the
box measured along the sheath and the sheath extends into the
box no less than i/4 inch, securing the cable to the box shall
not be required.
SUBSTANTIATION: This sentence as written in the 1978 NEC has
created considerable confusion. The sentence Is being rewritten
to c l a r i f y its original intent.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 13A. Present.
requlroment is necessary.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-7(c): Reject
CMP 9
SUBMITTER: H.F. van der Voort, Cleveland, OH
]~-OP
' -O~FA-CT. 16 Changesentences 4 and 5 to read: Clamping o f '
"i~'-dTv-J'dual conductors or cables to the box shall not be required
where supported within 8 inches of the box. Where rigid
nonmetallic conduit is installed with nonmetallic boxes or
f i t t i n g s , the conduit shall be secured to such boxes and "
f i t t i n g s in an approved manner.
SUBSTANTIATION: The present Code wording lacks c l a r i t y . In
addition, i t has not been demonstrated by f i e l d failures that
nonmetallic boxes when installed as described above constitute a
hazard, and until the 1978 Code revision, this was the accepted
procedure. In fact, even when clamps are provided for they are
often not used. When recemmended changes increase costs, their
need should be clearly demonstrated.
PANEL RECOMMENDATION: Reject.
PANEL COM~iENT: Present requirement is necessary as i t applies
to the fourth sentence. See Committee action on Proposal No.
13A for the intent of the f~fth sentence.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-7(c): Reject
CMP 9
SUBMITTER: Idaho Chapter IAEI
I~'OP-O-S~--~.
• 17 Delete last two sentences.
end of the third sentence of 370-7(c), change the
"period" to a "comma" and add "individual conductors and cables
shall be secured to such boxes" to read:
Where nonmetallic-sheathed cable is used¢ the cable assembly,
including the sheath, shall extend into theXbox no less than 1/4
inch through a nonmetalllc-sheathed cable knockout opening,
individual conductors and cables shall be secured to such boxes.
SUBSTANTIATION: There is no assurance that the sheath of
nonmetallic sheathed cable wlll remain in the nonmetallic box
when the device Is inserted into the box even though the cable
is strapped within 8 inches as required. I t is Just as
important that the cable sheath remains in a single gang box as
any other type of box.
PANEL RECOM&iENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent. There Is no evidence the present Code is
inadequate.
370-10 and 380-9: Reject
CMP 9
SUBMITTER: NormanB. Cooney, Parma, Ohio
19 After last word in paragraph "therefrom" insert
"but no more than 1/8 inch."
SUBSTANTIATION:' Since no dimensions are given for the
projection of the box, i t could conceivably be out one (1) inch
or more. By limiting the projection to I / 8 inch you would be
able to comply wlth 380-9 (faceplates to seat against the wall
surface).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered. No •
significant contribution to safety would result.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
370-I0, E~ception-(New): Reject
CMP 9
SUBMITTER: Ted Steppe, STEPP-ELEX Corp.
]~-OIR~{~]~-~.'\20 Add a new exception as follows:
. l~-x-Eeption: The front edge of box need not be flush with wall
surface I f an approved cover plate having a recessed center
section which effectively seals the box front and the adjoining
wall surface Is used.
SUBSTANTIATION: The problem: The extra thickness of paneling
when added to a wall means the electrical outlets and switches
must be moved out to make them flush with the new wall surface.
This is a project in i t s e l f and can be very costly and time
consuming. The alternative is to shlm out the electrical device
which could create a potential f i r e hazard for lack of proper
sealing of the electric box. Most home owners use the alternate
method.
The answer: The STEPP-PLATE has a recessed center area of
sufficient slze to effectively seal the electrical box as well
as any approved cover. The advantage we have over other covers
Is that STEppoPLATE also has the thickness of a new wall
covering b u i l t into I t . This insures a tight f i t to both the
electric box and the wall surface.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirenent is necessary. I f the
faceplate is changed later to a standard type, the installation
will be In violation of the Code.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Eckardt, Cramer.
COMMENTON VOTE:
DEMING: I would vote to accept this proposal i f i t were
reworded to limit the exception to apply only where paneling or
some similar finished surface, not over 1/4 Inch thick is
applied over an existing wall.
EXPLANATION OF VOTE:
ECKARDT: I can agree with the submltter and also wlth his
substantiation under Proposal No. 22 i f the use of the device is
limited to rework. I suggest the proposal be prefixed "For
remodeling work the front edge etc."
CRAMER: The proposal has merit. The reason for rejection is
i f the faceplate is changed later to a standard t~qoe, a
violation would occur. I f this change were made, outlets and
switches would then have to be moved out to make them flush.
There's no difference in the work. I t ' s Just that In the latter
case, I f the proposed faceplate were never changed, that work
would never be required.
162
370-11: Accept
CMP g
SUBMITTER: NormanB. Cooney, Parma, Ohio
21 After "Repairing Piaster" add "and drywall or
~oard."
After'"Plaster" ( f i r s t word in sentence) add
"drywall or plasterboard."
SUBSTANTIATION: Plasterboard or Drywall is used in 95 percent
of today's construction end the oversight in not having included
I t in previous Code changes eludes me.
This paragraph, llke so many others ,in the Code, mentions a
specific covering "plaster" and does not address i t s e l f to other
forms of wall and/or ceiling coverings.
The end result is an untenable position for the enforcing
authority explaining why this also applies to other forms of
plaster-content wall coverings when the Code mentions no other
forms. When appeals by contractors are refused by City Building
Board of Appeals, they then f i l e in Con~on Pleas Court and t h e
Judge is usually not concerned wlth the intent of the CMP, but
the explicit wording of the article or paragraph in dispute.
Since drywall construction has been used extensively since the
end of World War I I by builders, I believe i t is time to use
contemporary wording in the Code to alleviate the problems
caused by outmoded building standards.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECO~ENDATION: "
AFFIRMATIVE: g.
NEGATIVE: Barker, Biermann, Cock.
EXPLANATION OF VOTE:
BARKER: This is a necessary requirement to protect wood
constructed walls from arcs, sparks and molten metal coming in
contact with combustible walls and framing. I t is just as
enforceable as any other safety requirement. Any loss from this
would surely be called an electrical f i r e .
BIERMANN: Thls is a building code rule. Electricians cannot
be responsible for the installation practices of other tradesmen.
COCK: I believe that Section 370-11 should be deleted from
the Code or changed because the present wording is entirely too
restrictive and compliance is impossible in most cases. I t
should be changed to require that gaps o~ open spaces be held to
the minimum for practical working conditions. I agree that
Section 370-11 should be changed to apply to all materials i f
this Section remains in the Code. However, I would like to see
the Section reworded to reflect reality.
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Revise the second paragraph of 370-13 to read as follows:
"Boxes installed in walls of previously occupied buildings or In
walls In which there are no structural menfoers shall be
supported by the use of devices, clan~s or anchors which will
provide the secure and rigid installation required by this
ISection of the Code."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-13: Reject
CMP 9
SUBMITTER: DeanWoelber, Hull, IA
PROPO-S-A-C~." 25 Proposedwording of new paragraph to be added at
t--F;-e-en-d'-of 370-13 is as follows: "Threaded boxes or f i t t i n g s
not over 100 cubic inches in size shall be considered to be
adequately supported i f at least one conduit is threaded into
the box wrenchtight, and is securely fastened to the surface on
which i t is carried as required by Articles 345-12, 136-12, and
by this article. The box shall have no other means of support
readily available. The conduit shall be supported at least
twice, one of these supports being no further than 18 inches
from the box."
SUBSTANTIATION: Manytimes i t can be in,possible to securely
fasten a box exactly where i t is needed or wanted, because the
surface to which i t should be mounted is either an irregular
shape, a material such as glass, or some type of b r i t t l e
plastic. In these situations, i t could be Just as good i f not
better to support the box by the conduit threaded into the box.
The conduit must be.supported at least twice, one with 18 inches
of the box which will give the box a rigid support, and the
second support would keep i t from twisting.
PANEL RECOMMENDATION: Reject.
P/~I~EL COMMENT: Present requirement is necessary. The Panel
does not agree with the supporting comment.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
370-14: Reject
CMP g
SUBMITTER: NormanB. Cooney, Parma, Ohio
26 After "not less than" in second sentence, delete
"15/16 inches" and add "that specified in Table 370-6(a) and
370-6(b)".
SUBSTANTIATION: All devices measure7/8 inch to 1 1/8 inches.
Obviously any device measuring 15/16 inches and more cannot be
used in this box so I will address myself to those measuring 7/8
inch. Not wishing to fractionalize, I will use whole numbers.
The box is. 6 cu. in. and using 14-2 w/grnd., the conductors
equal 6 cu. in. which simply means you could not use a flush
device in this box. With a device and cable clan~o in the box
you could not comply with Table 370-6(a) and (b). I have not
mentioned EMT because the l~cknut measures 1 I/8 inches and is
physically impossible to install in this box. Mathematically
speaking, thls box cannot be used for flush devices.
PANEL RECOMMENDATION: Reject.
P~NEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-11, Exception-(New): Reject
CMP 9
SUBMITTER: Ted Steppe, STEPP-ELEXCorp.
PROPOSAL: 22 Add a new exception as follows:
-~-~ception: Wall Surface need not contact the edge of th e
electrical box i f an approvedcover plate having a recessed
center section which effectively seals the box front and the
adjoining wall surface is used for the purpose of recessing a
device into the wall.
SUBSTANTIATION: The box could be set flush with the stud in new
construction. Then the receptacle or switch would be recessed
the thickness of the finished wall. This would prevent the
switch or cord cap and receptacle from being damaged when heavy
objects are pushed against the wail. This would also protect
the cord caps and switches in high t r a f f i c areas frombeing hit
and damaged.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 20.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
COMMENT ON VOTE:
ECKARDT: This change is not needed regardless of the outcome
of Proposal No. 20.
DEMING: Allowing receptacles to be recessed the thickness of
the finished wall will lead to the practice of Jerking or
pulling directly on the cord to remove the plug from the
receptacle.
370-17(b): Accept
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
PITOPO-S~Z-~. 27 See the Technical Subcommittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Revise paragraph 370-17(b) to read: "Boxes listed
specifically for this application shall be used for receptacles
located in the floor.
Exception: Boxes located in elevated floors, of show windows
and similar locations where the (authority having Jurisdiction
judges them to be free from physical damage, moisture, and d i r t . "
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-13: Accept
CMP g
SUBMITTER: J.J. Kark, National Electrical Manufacturers
~ o n
PROPOSAL: 23 In f i r s t paragraph, revise second sentence to
Where nails are used as a mounting means and pass through the
interior of the box, they shall be located so that they do not
interfere with the installation of the device and are within 1/4
inch of the back or ends of the box.
SUBSTANTIATION: For boxes such as 3-1/2 inch deep switch boxes
or boxes with in turned device mounting ears, through nails
located within 1/4 inch of the ends of the box can give less
interference and better structural support than nails within I/4
inch of the back of the box.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
370-13: Accept
CMP 9
SUBMITTER: TSC.Approvedfor the Purpose
PITOI~CI--T.
• 24 See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
370-18(c): Accept
CMP 9
SUBMITTER: TSC-Approved.for the Purpose
PROPOSAL: 28 See the Technical Subcommittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete "approved for the purpose" and insert "compatible with
the box or f i t t i n g construction and suitable for the conditions
\
of use."
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
163
370-19: Reject
CMP 9
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
29 Add a paragraph, revise Exception No. 1, and add
new Exception Nos. I and 2.
A work space at least 24 inches horizontally and 24 inches in
height shall be provided in front of each junction, pull and
outlet box. Access thereto shall be provided by a space not
less than 24 inches in height and 20 inches in width. Crawl
holes, scuttles or similar openings to such space shallbe not
less than 18 inches by 18 inches in size.
Exception No. I : Boxes approved For the purpose shall be
permitted where covered by a thin coating of plaster or covered
by gravel-like aggregate or noncohesive granulated soil i f their
location is effectively identified and accessible for
excavation; or
Exception No. 2: Boxes that are listed for use as pull or
Junction boxes and are an integral part of a recessed fixture or
approved appliances; or
Exception No. 3: Outlets supplying b u i l t - i n appliances such
as gas ovens and the like where there are ho conductors in the
outlet box except the supply conductors terminating therein and
the appliance is connected to the outlet in an approved manner.
SUBSTANTIATION: The present vague and general requirements for
accessibility to Junction and outlet boxes are unenforceable in
new construction conditions as i t is not possible to know the
conditions of, access, especially in attic or undeP floor spaces,
until the construction is complete. To be enforceable a
specific clear area as proposed in this requirement must be
stated. .The proposed requirement has been in effect for many
years in the City of Los Angeles and has proven to be effective,
reasonable and enforceable.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered. No
evidence to support the suggested change.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
370-20(b): Reject
CMP 9
SUBMITTER: Harry Silver, Silvine, Inc.
PROPOSAL: 32 Revise as follows:
~-~ Thickness of Metal. Sheet steel boxes or die cast
aluminum boxes and f i t t i n g s not over 100 cubic inches in size
shall be made from metal not less than .0625 inches thick. The
wall of a malleable iron box, permanent-mold cast aluminum box
permanent-mold brass or bronze box shall not be less than
2/32-inch thick. Other cast metal boxes shall have a wail
thickness of not less than 1/8-inch.
SUBSTANTIATION: The reason for the request for change is
because the integrity of the die cast aluminum box will easily
endure any of the impact, compression, and other mechanical
strength tests that plastic boxes are now being subjected to for
similar uses and exceed requirements at the upper and lower
temperature levels. Aluminum has the advantage of not needing a
protective finish to provide the l i f e tests presently required
from steel boxes. The die cast box has the added advantage that
we can design for added wall thickness at various points of
possible stress to assure the integrity of the boxes under the
necessary tests. At the areas of load such as the threaded
holes, the thickness can be increased to provide any mechanical
strength that may be required.
The connectors may be designed into the box at time of
manufacture, eliminating possible build up of tolerance errors
in assembly, and mistakes and misuse of parts. The thinner die
cast boxes will be of great advantage to the industry and public
in general by reducing the energy costs needed to produce the
product. I t will be possible to save a good quantity of
material by lowering the wall thickness. Benefits are four fold
- saving of energy, material, ease of use, and reduction of
freight costs to Job site.
Present variety of'die cast boxes with .093 inch wall
thickness have more than required mechanical strength. This
lighter product is more handy at the time of installation and at
the same time has all benefits of boxes with thicker walls.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: We believe the present thickness is necessary.
Thickness is necessary to contain arcing faults.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-19: Reject
.
CMP 9
SUBMITTER: Southwestern Section IAEI
P-R-OP
' -O-S~A-L-~ 30 Ad~ a second paragraph to present Section 370-19
A work space at least 18 inches horizontally and 18 inches in
height shall be provided in. front of each Junction, pull and
o~tlet box. Access thereto shall be provided by a space not
less than 18 inches in height and 20 inches in width. Crawl
holes, scuttles or similar openings to .such space shall be not
less than 18 inches by 18 inches in size.
Exception No. 1: Boxes approved for the purpose shall be
permitted where covered by gravel-like aggregate or non-cohesive
granulated soll i f their location is effectively identified and
accessible for excavation; or
Exception No. 2: B6xes that are listed for use as pull or
junction boxes and are an integral part of a recessed fixture or
approved appliances; or
Exception No. 3: Outlets supplying b u i l t - i n appliances such
as gas ovens and the like where there are no conductors in the
outlet box except the supply conductors terminating therein and
the appliance is connected to the outlet in an approved manner.
'SUBSTANTIATION: The present vague and general requirements for
accessibility to junction and outlet boxes are unenforceable in
new construction conditions as i t is not possible to know the
conditions of access, especially in attic or under floor spaces,
until the construction is complete. To be enforceable, a
specific, clear area as proposed in this requirement must be
stated. The proposed requirement has been in effect for many
years in the City of Los Angeles and has proven to beeffective,
reasonable~and enforceable.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered. No
evidence to support the suggested change.
VOTE ON PANELREC~ENDATION: Unanimously Affirmative.
370-20(b): Reject
CMP g
SUBMITTER: R. C. Medley, Squire D Co.
33 Revise as fol]ows:
~-T Thickness of Metal. Sheet steel boxes and f i t t i n g s not
over 100 cubic inches in size shall be made of a sheet thickness
not less than 0.0625 inches. The wails of a malleable iron box
and a die-cast or permanent-mold, case aluminum, zinc, brass or
bronze box shall not be less than 3/32-inch thick unless
suitably reinforced by ribs. Other cast metal boxes shall have
a wall thickness not less than 1/8-inch unless/suitably
/
reinforced by ribs.
SUBSTANTIATION: Clarification of sheet steel thickness is
necessary to identify the starting thickness of ~ drawn or bent
steel box where the thickness is reduced slightly by the metal
forming operation with no significant loss of strength or
longevity.
The omission of die-cast zinc of comparable thickness has
restricted the use of an available material as corrosion
resistant as aluminum.
The reduction of minimum wall thickness for castings is now
feasible by modern technology. I t is no longer necessary or
economical t o r e q u i r e thickness where strehgth and r i g i d i t y is
achievable by suitable design.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirement is necessary. The Panel
does not agree with the supporting comment. Thickness is needed
to contain arcing faults.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-21: Reject
CMP 9
SUBMITTER: R. C, Medley, Square D Co.
~ 3 4
Revise as follows:
~Covers.
Sheet steel covers shall be made of a sheet
thicknessnot less than .0625 inches or be suitably reinforced
by ribs. Die-cast or permanent-mold cast metal covers shall be
not less than 3/32-inch unless suitably reinforced by ribs.
Other cast metal covers shall be not less than 1/B-inch unless
suitably reinforced by ribs. Covers of porcelain or Other
insulating material shall be permitted i f of such-form and
thickness as to afford the required protection and strength.
SUBSTANTIATION: Editorial changes requested to c l a r i f y
construction details. Present wording intended~to correlate .
with Sections 370-20 and 373-10 but is ambiguous and confusing.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirement is necessary. The Panel
does not agree with the supporting comment. Thickness is needed
to contain arcing faults.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
370-19; Exception: Accept
(~
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
31 See the Technical Subcommittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose''' and add the word
"Listed" at the beginning of the exception.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Cramer, Deming.
EXPLANATION OF VOTE:
CRAMER: Listed boxes in the size desired are not always
available. Field fabrication or modification is sometimes
required. Consequently, the box cannot be listed. Remove
"approved for the purpose" and replace with "suitable for the
envirooment."
DEMING: I am opposed to the word " l i s t e d . " Listed as defined
in Article 100 (definitions) woul~ prohibit the use of custom
made boxes. In instances where a one-of-a-kind box is r~quired,
" l i s t i n g " is not practical. Designed is a more appropriate word.
164
Table 372-4B
Comparison of Specific Applications of
Enclosures for Outdoor Nonhazardous Locations
ARTICLE 372 -- ENCLOSURETYPES
Article 372-(New): Reject
CMP g
SUBMITTER: Francis A. Marta, Circle A WProducts Co.
35 Add a new article as follows:
Article 372 -- ENCLOSURE TYPES
372-1. Scope. This article covers the general requirements for
various types of enclosures for electrical equipment rated 600
volts nominal or less, installed in nonhazardous locations.
Exception to Scope: The enclosures described herein are not
intended to: .protect the enclosed equipment against conditions
such as condensation, icing, corrosion or contamination which
occur within the'enclosure or enters via the conduit or unsealed
openings; cover enclosures for rotating apparatus; or cover
means to prevent attempted entry or operation by unauthorized
personnel. This article does not cover requirements for wire
and cable.
Enclosures for use in hazardous locations shall conform to
Articles 500 through 517.
372-2. Purpose of Enclosures. Enclosures are constructed to
provide a degree of protection, when completely and properly
installed, against incidental contact with the enclosed
equipment and to provide a degree of protection to the enclosed
equipn~nt agalnstspecified environmental conditions.
372-3. Enclosure Type Descriptions. Enclosures shall be
identified with one or more types for the following
environmental conditions:
(a) Type 1-1ntended for indoor use primarily to provide a
degree of protection against contact with the enclosed equipment.
(b) Type 2-1ntended for indoor use primarily to provide a
degree of protection against limited amounts of falling water
and d i r t .
(c) Type.3-1ntended for outdoor use primarily~to provide a
degree of protection against windblown dust, rain, sleet and
external ice formation.
(d) Type 3R-Intended for outdoor use primarily to provide
degree of protection against falling rain, sleet and external
ice formation.
(e) Type 3S-Intended for outdoor use primarily to provide a
degree of protection against windblown dust, rain and sleet, and
to provide for operation of external mechanism when ice laden.
(f) Type 4-1ntended for indoor or outdoor use primarily to
provide a degree of protection against windblown dust and rain,
splashing water and hose-directed water.
(g) Type 4X-Intended for indoor or outdoor use primarily to
provide a degree of protection against corrosion, windblown dust
and rain, splashing water and hose-directed water.
(h) Type 5-Intended for indoor use primarily to provide a
degree of protection against dust and falling dirt.
(i) Type 6-Intended for indoor or outdoor use primarily to
provide a degree of protection against the entry of water during
occasional temporary submersion at a limited depth.
(J) Type 6P-Intended for indoor or outdoor use primarily to
provide a degree of protection against the entry of water during
prolonged submersion at a limited depth.
(k) Type 11-1ntended for indoor use primarily to provide, by
oil immersion, a degree of protection to enclosed.equipment
against the corrosive effects of liquids and gases.
(1) Type 12-Intended for indoor use primarily to provide a
degree of protection against dust, falling d i r t and dripping
water.
(m) Type 12K-Enclosures with knockouts intended for indoor
use primarily to provide a degree of protection against dust,
falling d i r t and dripping water other than at knockouts.
(n) Type 13-1ntended for indoor use primarily to provide a
degree'of protection against dust, spraying of water,'oil and
noncorrosive coolant.
372-4. Applications. Tables 372-4A and 372-4B are comparisons
of specific applications of indoor and outdoor enclosures.
Provides a Degree of
Protection Against the
Following Enyironmental
Conditions
Incidental contact with
the enclosed equipment
Rain, snow and sleet*
Sleet**
Windblown dust
Hosedown
Corrosive agents
Occasional temporary
submersion
Occasional prolonged
submersion
X X X X
X X
X X
X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CMP
372-i. This article covers the general requirements for surface
mounted enclosures for the following equipment rated nominally
600 volts or less installed in nonhazardous locations: Circuit
Breakers, Industrial Controls, Motor Controllers, Motor Control
Centers, Panelboards, Switchboards, Switches, Transformers.
372-2. Application to other articles. Equipment for use in
hazardous locations shall conform to Articles 500 through 517.
372-3. Purpose of Enclosures. Enclosures shall be constructed
to provide a degree of protection against accidental contact
with enclosed equipment and to provide ~ degree of protection
for the enclosed equipment against specified enviFonmental
conditions.
(f.p.n.) I t is recognized that enclosures do not protect the
enclosed equipment against conditions such as condensation,
icing, corrosion or contamination which occur within the
enclosure or enter via the conduit or unsealed openings.
372-5. Enclosure Types. Apparatus within the scope of this
article shall be marked with one or more of the following
enclosure type designations:
(a) Type I , where the enclosure is intended for only indoor
use, to provide protection against contact with enclosed
equipment.
(b) Type 2, where the enclosure is intended for only indoor
use, primarily to provide a degree of protection against limited
• nounts of falling water and d i r t .
(c) Type 3, where the enclosure is intended for outdoor use,
primarily to provide a degree of protection against windblown
dust, rain and sleet and from external ice formation.
(d) Type 3R, where the enclosure is intended for outdoor use,
primarily to provide a degree of protection against falling rain
and sleet and against external ice formation.
(e) T)qoe3S, where the enclosure is intended for outdoor use,
primarily to provide a degree of protection against windblown
X X
X.
X
X
ARTICLE 372°ENCLOSED APPARATUS
X X
X X
X XXX X X X
X X
X X
X
X , X
X
[
Article 372-(New): Reject
SUBMITTER: JamesM. Rice, Allen-Bradley Co.
PROPOSAL: 36 Add new article as follows:
1 2 4 4X'5 6 6P 11 12 12K 13
XX X
X
X
X
6 6P
372-6. Operating Mechanisms. Externally operated mechanisms
such as circuit breakers or disconnect operating levers ahd
other mechanisms including pushbuttons and p i l o t lights when
installed through the enclosure wall shall provide the same
• degree of environmental protection as the enclosure.
SUBSTANTIATION: Type numbers have been associated with various
enclosures for many years but with a somewhat lack of
standardization except for a few types, and these have not been
too well publicized.
Electrical contractors, electrical inspectors and users have
f e l t a need for having a basis for selecting and accepting the
proper enclosures for the various applications with proper
markings to meet the requirements of Sections 110-3 and 110-11
of the National Electrical Code.
PANEL RECOMMENDATION: Reject.
PANEL COGENT: The C~ believes that extending the requirements
as intended by this Proposal i s n o t appropriate at this time.
VOTE ON PANELRECOt~iENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Barker.
EXPLANATION OF VOTE:
BARKER: The NEMAtype numbers and classifications are used
throughout the industry wherever enclosures are used, specified
on plans, liste~d by manufacturers or suppliers. The time is
long past due for the Code to be consistent with the industry
and give guidance on this subject. The reasoning that industry
may revise this type of numbers is unacceptable because the
entire Code is always being updated and any changes in these
types, etc., could be accepted as any other Code change. The
time to act is new.
Type of Enclosure
XX X XXX X X X
XXX XXX X X X
X
X
4 4X
*External operating mechanisms are not required to be
operable when the enclosure is ice covered.
**External operating mechanisms are operable when the
enclosure is ice covered.
Table 372-4A
Comparison of Specific Applications of
Enclosures for Indoor Nonhazardous Locations
.,Prqvides a Degree of
Protection Against the
Following Environmental
Conditions
Incidental contact with
the enclosed equipment
Falling Dirt
Falling l!quids and
light splashing
Dust, l i n t , fibers and
flyings
Hosedown and splashing
water
Oil and coolant seepage
Oil or coolant spraying
and splashing
Corrosive agents
Occasional temporary
submersion
Occasional prolonged
submersion
T~pe of Enclosure
3 3R 3S
X
X X
X
165
dust, rain and sleet and provides for operation of external'
mechanisms when ice laden.
(f) Type 4, where the enclosure is intended for indoor 'or
outdoor use, primarily to provide a degree of protection against
windblown dust and rain, splashing water and hose directed water
under specified conditions.
(g) Type 4X, where the enclosure is intended for indoor or
outdoor use, primarily to provide a degree of protection against
corrosion, windblown dust and rain, splashing water and hose
directed water under specified conditions.
(h) Type 5, where the enclosure is intended for only indoor
use, primarily.to provide a degree of protection against dust
and falling dirt.
(i) Type 6, ~here the enclosure is intended for indoor or
outdoor use, primarily to provide a degree Of protection against
the entry of water during occasional, temporary submersion at a
limited depth.
(J) Type 6P, where the enclosure is intended for indoor or
outdoor use, primarily to provide a degree of protection against
the entry of water during prolonged submersion at a limited
depth.
(k) Type 11, where the enclosure is intended for only indoor
use, primarily to provide a degree of protection for the
enclosed equipment against corrosive liquids and gases, by
immersion in o i l .
(I) Type 12, where the enclosure is intended for only indoor
use, primarily to provide a degree of protection against dust,
falling d i r t and dripping water.
(m) Type 12K, where the enclosure includes knockouts that are
utilized by the installer to result in an installation
equivalent to Type 12.
(n) Type 13, wfiere the enclosure is intended for only indoor
use, primarily to provide a degree of protection against dust,
spraying of water, oil and noncorrosive liquids.
372-7. Indoor Aoplcations. Enclosure types appropriate for the
anticipated indoor environmental conditions shall be used.
Enclosures shall be selected in accordance with Table 372-7.
372-11. Materials. All enclosures shall be contructed of base
materfals that will not support combustion in air.
372-13. Conductor Entry. When installed, conductor entry
f i t t i n g s shall provide the some degree of environmental
protection as the enclosure.
372-15. Operating Mechanisms. Externally operating mechanisms
such as those for circuit breakers or disconnect switches, and
other mechanisms including push-buttons and pilot lights when
installed through the enclosure wall shall provide the some
degree of environmental protection as the enclosure. •
SUBSTANTIATION: This addition to the National Electrical Code
will promote safety by assisting users and inspectors in
determining the proper enclosure for electrical equipment for
the environment. The enclosure type numbers in this article
have been used in the trade and in industry for many years.
Despite this fact, there is confusion as to the characteristics
of the various type designations. Improper enclosures are the
source of many accidents involving injury to workers and the
large property losses. Examplesof improper enclosures can be
cited from numerous product l i a b i l i t y litigations.
Electrical inspectors will find this new section particularly
useful because of the clear and concise descriptions Of the
types of enclosures.
PANEL RECOMMENDATION: Reject.
PANEL C~MMENT: 'The CMP believes that extending the requirements
as intended by thls Proposal is not appropriate at this time.
VOTE ON PANELRECO~ENDATION:'
AFFIRMATIVE: 11.
NEGATIVE: Barker.
EXPLANATION OF VOTE:
BARKER: Samecomment as Proposal No. 35.
ARTICLE 373 -- CABINETSAND CUTOUTBOXES
373: Reject
.
CMP 9
SUBMITTER: Eldon Hemsey, Wilmington, DE
PROPOSAL: 37 All exterior or interior switch cabinets, having
expos-oseB-uninsulated electrical (current carrying) components
which are accessible when the cabinet door is open, shall be
provided with a lock or other device to prevent children from
opening them.
SUBSTANTIATION: Manyexisting disconnect switches, particularly
on exterior air conditioning condensing units, mounted on pads
on the ground, are within easy reach of curious small children.
I f these boxes can be easily opened, a child could touch the
current carrying elements inside the cabinet and be electrocuted.
There are millions (or at least thousands).of these switch
cabinets, mounted on air conditioning condensing units outside
houses and garden apartment buildings all over the country,
which are not locked, so as to protect children from injury or
death.
Perhaps local inspecting o f f i c i a l s should be alerted to the
danger, and switch cabinet manufacturers required to provide a
child-proof door catch, In addition to the padlock hasp they
ready provide.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: This equipment is already provided with means
for locking.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
TABLE 372-7-Enc.losures for Indoor Nonhazardous Locations
ENVIRONMENTAL CONDITIONS
Type of Enclosure
Provides a Degree of
Protection Against
1 2 4 4X566P11
12 13
Incidental contact
with enclosed equipmt.X X X X X
Falling d i r t . . . . . . . . . . . X X X X X
Falling liquids and
/
light splashing. . . . . . .
X X X
Dust, l i n t , fibers
and flyings . . . . . . . . . . .
X XXX
Hosedown and splashing
water. . . . . . . . . . . . . . . . .
X X
Oil andcoolant
seepage. . . . . . . . . . . . . . .
Oil or coolant
spraying and
splashing . . . . . . . . . . . . . .
Occasional temporary
submersion. . . . . . . . . . . .
Occasional prolonged
submersion. . . . . . . . . . . .
X X X X X
X X X X X
X
XXXX
X
X
X
XX
X X
X X
X
372-9. Outdoor Applications. Enclosure types appropriate for
the anticipated outdoor environmental conditions shall be used.
Enclosures shall be selected in accordance with Table 372-9.
373-6, 380-18 and 384-25: Accept
CMP 9
SUBMITTER: a.J. Kark, National Electrical Manufacturers Assn.
38 Revise as follows:
~Tr3~--CNo change).
(a) (No change).
Revise t i t l e of table as follows:
Table 373-6(a) - Minimum Width of Wiring Gutters and Minimum
Wire Bending Space for 373-6(b)(I).
Revise present (b) as follows:
(b) Wlre Bending Space at Terminals. Wire bending space at a
terminal shall be provided in accordance with (1) or (2) below:.
(1) Table 373-6(a) shall apply where the conductor is
substantially deflected, but not more than 90 degrees and not
more than once as i t leaves the terminal and .enters the gutter.
Table 373-6(a) shall also apply where an individual connector of
the removable or lay-in type for each conductor is furnished
wlth the equipment or designated as suitable by marking on the
equipment.
TABLE 372-g-Enclosures for Outdoor Nonhazardous
Locations
ENVIRONMENTAL CONDITIONS
Type of Enclosure
Provides a Degree of
Protection
Against
Ty3 Ty3R Ty3S Ty4 Ty4X Ty5 Ty6P
Incidental
contact with
enclosed equipment. . . . . . . . . . . . . X
Rain, snow
and sleet* . . . . . . . X
Sleet** . . . . . . . . . . .
Windblown dust. . . . X
Hosedown
Occasional
te~iporary
submersion. . . . . . .
bccasional
prolonged
submersion. . . . . . . .
i
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
,X
I
* External operating mechanisms are not required to be operable
when the enclosure is ice covered.
** External operating mechanlsms are operable when the enclosure
Is Ice covered. ".
166
dust, rain and sleet and provides for operation of external'
mechanisms when ice laden.
(f) Type 4, where the enclosure is intended for indoor 'or
outdoor use, primarily to provide a degree of protection against
windblown dust and rain, splashing water and hose directed water
under specified conditions.
(g) Type 4X, where the enclosure is intended for indoor or
outdoor use, primarily to provide a degree of protection against
corrosion, windblown dust and rain, splashing water and hose
directed water under specified conditions.
(h) Type 5, where the enclosure is intended for only indoor
use, primarily.to provide a degree of protection against dust
and falling dirt.
(i) Type 6, ~here the enclosure is intended for indoor or
outdoor use, primarily to provide a degree Of protection against
the entry of water during occasional, temporary submersion at a
limited depth.
(J) Type 6P, where the enclosure is intended for indoor or
outdoor use, primarily to provide a degree of protection against
the entry of water during prolonged submersion at a limited
depth.
(k) Type 11, where the enclosure is intended for only indoor
use, primarily to provide a degree of protection for the
enclosed equipment against corrosive liquids and gases, by
immersion in o i l .
(I) Type 12, where the enclosure is intended for only indoor
use, primarily to provide a degree of protection against dust,
falling d i r t and dripping water.
(m) Type 12K, where the enclosure includes knockouts that are
utilized by the installer to result in an installation
equivalent to Type 12.
(n) Type 13, wfiere the enclosure is intended for only indoor
use, primarily to provide a degree of protection against dust,
spraying of water, oil and noncorrosive liquids.
372-7. Indoor Aoplcations. Enclosure types appropriate for the
anticipated indoor environmental conditions shall be used.
Enclosures shall be selected in accordance with Table 372-7.
372-11. Materials. All enclosures shall be contructed of base
materfals that will not support combustion in air.
372-13. Conductor Entry. When installed, conductor entry
f i t t i n g s shall provide the some degree of environmental
protection as the enclosure.
372-15. Operating Mechanisms. Externally operating mechanisms
such as those for circuit breakers or disconnect switches, and
other mechanisms including push-buttons and pilot lights when
installed through the enclosure wall shall provide the some
degree of environmental protection as the enclosure. •
SUBSTANTIATION: This addition to the National Electrical Code
will promote safety by assisting users and inspectors in
determining the proper enclosure for electrical equipment for
the environment. The enclosure type numbers in this article
have been used in the trade and in industry for many years.
Despite this fact, there is confusion as to the characteristics
of the various type designations. Improper enclosures are the
source of many accidents involving injury to workers and the
large property losses. Examplesof improper enclosures can be
cited from numerous product l i a b i l i t y litigations.
Electrical inspectors will find this new section particularly
useful because of the clear and concise descriptions Of the
types of enclosures.
PANEL RECOMMENDATION: Reject.
PANEL C~MMENT: 'The CMP believes that extending the requirements
as intended by thls Proposal is not appropriate at this time.
VOTE ON PANELRECO~ENDATION:'
AFFIRMATIVE: 11.
NEGATIVE: Barker.
EXPLANATION OF VOTE:
BARKER: Samecomment as Proposal No. 35.
ARTICLE 373 -- CABINETSAND CUTOUTBOXES
373: Reject
.
CMP 9
SUBMITTER: Eldon Hemsey, Wilmington, DE
PROPOSAL: 37 All exterior or interior switch cabinets, having
expos-oseB-uninsulated electrical (current carrying) components
which are accessible when the cabinet door is open, shall be
provided with a lock or other device to prevent children from
opening them.
SUBSTANTIATION: Manyexisting disconnect switches, particularly
on exterior air conditioning condensing units, mounted on pads
on the ground, are within easy reach of curious small children.
I f these boxes can be easily opened, a child could touch the
current carrying elements inside the cabinet and be electrocuted.
There are millions (or at least thousands).of these switch
cabinets, mounted on air conditioning condensing units outside
houses and garden apartment buildings all over the country,
which are not locked, so as to protect children from injury or
death.
Perhaps local inspecting o f f i c i a l s should be alerted to the
danger, and switch cabinet manufacturers required to provide a
child-proof door catch, In addition to the padlock hasp they
ready provide.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: This equipment is already provided with means
for locking.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
TABLE 372-7-Enc.losures for Indoor Nonhazardous Locations
ENVIRONMENTAL CONDITIONS
Type of Enclosure
Provides a Degree of
Protection Against
1 2 4 4X566P11
12 13
Incidental contact
with enclosed equipmt.X X X X X
Falling d i r t . . . . . . . . . . . X X X X X
Falling liquids and
/
light splashing. . . . . . .
X X X
Dust, l i n t , fibers
and flyings . . . . . . . . . . .
X XXX
Hosedown and splashing
water. . . . . . . . . . . . . . . . .
X X
Oil andcoolant
seepage. . . . . . . . . . . . . . .
Oil or coolant
spraying and
splashing . . . . . . . . . . . . . .
Occasional temporary
submersion. . . . . . . . . . . .
Occasional prolonged
submersion. . . . . . . . . . . .
X X X X X
X X X X X
X
XXXX
X
X
X
XX
X X
X X
X
372-9. Outdoor Applications. Enclosure types appropriate for
the anticipated outdoor environmental conditions shall be used.
Enclosures shall be selected in accordance with Table 372-9.
373-6, 380-18 and 384-25: Accept
CMP 9
SUBMITTER: a.J. Kark, National Electrical Manufacturers Assn.
38 Revise as follows:
~Tr3~--CNo change).
(a) (No change).
Revise t i t l e of table as follows:
Table 373-6(a) - Minimum Width of Wiring Gutters and Minimum
Wire Bending Space for 373-6(b)(I).
Revise present (b) as follows:
(b) Wlre Bending Space at Terminals. Wire bending space at a
terminal shall be provided in accordance with (1) or (2) below:.
(1) Table 373-6(a) shall apply where the conductor is
substantially deflected, but not more than 90 degrees and not
more than once as i t leaves the terminal and .enters the gutter.
Table 373-6(a) shall also apply where an individual connector of
the removable or lay-in type for each conductor is furnished
wlth the equipment or designated as suitable by marking on the
equipment.
TABLE 372-g-Enclosures for Outdoor Nonhazardous
Locations
ENVIRONMENTAL CONDITIONS
Type of Enclosure
Provides a Degree of
Protection
Against
Ty3 Ty3R Ty3S Ty4 Ty4X Ty5 Ty6P
Incidental
contact with
enclosed equipment. . . . . . . . . . . . . X
Rain, snow
and sleet* . . . . . . . X
Sleet** . . . . . . . . . . .
Windblown dust. . . . X
Hosedown
Occasional
te~iporary
submersion. . . . . . .
bccasional
prolonged
submersion. . . . . . . .
i
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
,X
I
* External operating mechanisms are not required to be operable
when the enclosure is ice covered.
** External operating mechanlsms are operable when the enclosure
Is Ice covered. ".
166
Wires Per Terminal
(2) In all other cases, Table 373-6(b) shall apply.
Add new table as follows:
Table 373-6(b) - Minimum Wire Bending Space
at Terminals forX373-6(b)(2) in Inches
AWG or
Circular-Mil
Size of Wire
Wire Size
2
1
3
4 or More
Wires per Terminal
14-10
I
14-10
Not Spec.
8-6
1 1/2
4-3
.2 1/2
2
3 I/2
1
4 I/2
0
5
O0
6
000-0000
6 1/2
250 MCM
8
300 MCM
10
350 MCM
12
400-500 MCM
12
600-700 MCM
14
750 MCM
16
800-900 MCM 18
1000-1250 MCM 21
1500-2000 MCM 24
2
5
6
6 I/2
8
10
12
12
16
19
3
7
7 1/2
8
9
11
13
14
17
21
8
6
Not
Specified
I 1/2
2
4
3
2
3
3
3 1/2
0
2/0
4 I/2
5 1/2
6
3/0'
6 1/2
4/0
250
7
8 1/2
300
350
400
4
10
12
14
16
18
23
18
20
25
Bending space at terminals shall be'measured in a straight line
from the end of the lug or wire connector (in the direction that
the wire leaves the terminal) to the wall or barrier.
(c) (No change).
SUBSTANTIATION: Several proposals were made for the 1978 Code
t o increase wire bending space to make offset or double bends at
terminal points. These proposals were based on the application
of a multiplier to the existing Table 373-6(a). NEMAhas
sponsored a Fact-Findlng study which Underwriters' Laboratories
has conducted under guidance of a steering committee composed of
electrical inspectors, industrial users and manufacturers. The
purpose of the study was to establish factual data for the space
necessary to make wire bends and to install wire into connectors.
TheFact-Finding Report will be provided tO CI~~ g members.
Based on the result of this study, NEMAproposes the above text
for 373-6 and the additional Table 373-6(b).
The attached tabulation* cross references values in proposed
Table 373-6(b) with the Fact-Finding Study Project number for
which test results show successful installation.
* Attachments have been supplied to CHP members.
Table 373-6(b) establishes increased bending space
requirements f o r :
(1) all factory-installed connectors which are not of the
lay-in or removable type;
(2) field-installed connectors which are not designated by
the manufacturer as part of the equipment marking.
No changes are proposed in Table 373-6(a) except to clarify
its t i t l e . This existing table has been adequate for single
bends up to 90 degrees.
The values in Table 373-6(a) also apply for lay-in or
removable-type connectors where each connector accommodates only
a single conductor. This will f a c i l i t a t e the use of
field-installed connectors which may be dimensionally different
from the connectors Furnished with the equipment. This also
would require manufacturers to provide adequate bending space,
electrical clearances and markings for specific types of
field-installed connectors.
Tests 2C, 4G, 7H, lOB, I3F, 13J and 22B demonstrate that
single conductors can be installed using removable or lay-ln
lugs when gutter space is equal to the minimu~n amount required
by existing Table 373-6(a). These tests cover wire sizes from
#2 AWI; to 750 MCM. Additional supporting tests are in process
for conductor sizes No. 3, 1,and 2/0 AWG.
PANEL RECOMMENDATION: Accept as Revised:
373-6 No change. 373-6(a) No change.
Table 373-6(a) No change. Reword the end of footnote to
read: "to the wall, barrier or obstruction."
Revise 373-6(b) of the 1978 NEC to read as follows:
(b) Wire Bending Space at Terminals. Wire bending space at
each terminal shall be provided in accordance with (I) or (2)
below:
(I) Table 373-6(a) shall apply where the conductor does not
enter nor leave the enclosure through the wall opposite the
terminal.
Exception: Conductors which enter a second wire bending space
conforming to Table 373-6(b) for that conductor.
(2) Table 373-6(b) shall apply where the conductor enters
or leaves the enclosure through the wall opposite the terminal.
For removable (single barrel) compression (crimp) type
terminals, bending space may be reduced'2 inches for 3/0 AWG to
250 MCM and 3 inches for 300 to 750 MCM."
7
7 1/2
6 1/2
7 1/2
8 I/2
8
8 1/2
9
I0
12
13
10
ll
12
13
13
14
14
15
500
600
700
14
15
16
14
16
18
15
18
20
16
19
22
750
800
900
17
18
19
19
20
22
22
24
22
24
24
24
I000
1250
1500
20
22
24
1750
2000
24
24
lO
~
12
Bending space at terminals shall be measured in a straight line
from the end of the lug or wire connector (in the direction that
the wire leaves the terminal) to the wall~ barrier or
obstruction.
373-6(c) No change.
Add a new 380-18 as follows:
"380-18 Wire Bending Space..The wire bending space required by
Section 380-3 shall meet Table 373-6(b) spacings to the
enclosure wall opposite the llne and load terminals."
Add a new 384-25 as follows:
"384-25 Wire Bending Space in Panelboards. The enclosure for a
)anelboard shall have the top and bottom wire bending space
sized in accordance with Table 373-6(b) for the largest
conductor entering or leaving the enclosure. Side wire bending
space shall be in accordance with Table 373-6(a) for the largest
conductor to be terminated in that space.
Exception: Either the top or bottom wire bending space shall
be permitted to be sized in accordance with Table 373-6(a) where
at least one side wire bending space is sized in accordance with
Table 373-6(b) for the largest conductor to be terminated in
that space."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Burniston.
COMMENTON VOTE:
HOGAN: I have not voted negatively on this proposal, however,
I would like to call the attention of the general public some of
the provisions of this new proposal that may cause serious
problems in the field.
This proposal will permit some substantial reductions in
required bending provided a particular type of lug is utilized.
I t would seem to me that i t will be necessary for manufacturers
who intend that these special lugs be used with their equipment
and therefore provide the smaller space permitted by this
proposal will have to install the special lugs permanently in
such equipment so that the contractors, mechanics and inspectors
will know that only those lugs may be used in those enclosures.
There should be some public comment from all facets of the
industry so that this part of the proposal can be given further
consideration at the Novembermeeting of C~P 9.
BARKER: Voting affirmative is for "something better than
nothing." The fact finding study proved that more bending space
is a n~ust at terminations. There is no way that the
manufacturer can control how a panel or switch is used in the
field as to the point of entry or exit of any conductor or
raceway. Therefore, the bending space should be opposite of all
terminals. Time will prove that another change and retooling
will be mandated by contractors, users and safety enforcement
o f f i c i a l s . The needs for safety is there and proven and what is
available for use cannot continue to be mandated by the
manufacturers of this equipment in light of the proven facts.
LIEMAN: I haven't voted negatively on this proposal but would
like to be on record to discuss this at our next meeting in
December. I t is nly view that we will get a broader reaction at
our Eastern Section meeting in September as to whether this
Table 373-6(b). MinimumWire Bending Space at Terminals for
373-6{b){2) in Inches.
"
5 I/2
6
167
proposal will cause any problems.
EXPLANATION OF VOTE:
BURNISTON: While NEMAaccepts the proposed change in Section
373-6(a) and the associated Section 373-6(b) there is no
substantiation for the addition of new Sections 380-18 and
384-25. Section 373-6 as revised adequately covers the
requirements for enclosed switches, circuit breakers and
panelboards, and Sections 380-3 and 384-3(g) presently refer
back to Section 373-6.
Proposed Section 384-25 requires two (2) gutters large enough
for the main conductors where in practically all cases this is
not required to adequately wire the panelboard.
Table 373-6(b) - Minimum Wire Bending Space
in Inches in Enclosures Containin9 Terminals
AWGor
Circular Mil
Wire Size
14-10
8-6
4-3
2
1
0-00
OOO-OOOO
250 MCM
300-350 MCM
400-500 MCM
600-700 MCM'
750-900 MCM
1000-1250 MCM
1500-2000 MCM
Table 373-6(a)and 373-6(b): Reject
CMP 9
SUBMI1-FER: A. C. Clark, Manufacturing Chemists Association
PROPOSAL: 39 Add new Table 373-6(a). Note that the
~ s e s
and nunW)ers contained in the parentheses are the
only changes.
After the one sentence note to Table 373-6(a), add the
following. "Numbers in parentheses apply to conductors bent or
deflbcted more than once. Nund)ers not in parentheses appIy to
conductors bent or deflected once."
In Section 373-6(b) add the following at the end of the f i r s t
sentence. " I f a compression type pressure connector is used,
numbers in parentheses may be reduced to the.extent that i f the
compression type pressure connector were replaced with an
approved set- screw pressure connector, the requirements in the
parentheses would be met."
SUBSTANTIATION: The need.for increased wiring space for
conductors bent or deflected more than once wasestablished
three years ago by proposals for the 1978 National Electrical
Code. Disagreementon the amount of increased space led to the
appointment of a steering committee to agree upon and oversee a
series of tests. Such tests to determine an adequate amount of
bending space are nearing completion.
Based on the results of these tests, the proposed additions to
Table 373-6(a) cover conductors which'are bent or deflected more
than once. Included for background is summary (pages I to 5) of
such tests along with comments. Tests were not run on alI
bending spaces proposed. However, in view of results obtained,
these numbers are though~ to be reasonable.
The intent of the proposed addition to Section 373-6(b) is to
not penalize those wishing to use compression type pressure
connectors. These connectors are often longer than set-screw
pressure connectors. In many instances, purchased equipment
comes equipped with set-screw pressure connectors and
replacement of these with compression type is sometimes
impossible because of inadequate space per Table 373-6(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 38.
VOTE ON PANELRECO~MENDATION: UnanimouslyAffirmative.
14-10
8-6
43
Wires per Terminal
2
3
4
Not Specified
1½ (2)
2
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
3 (4~)
3~i (6)
5-(6,)
4 (7,)
6 (8)
. . .
7 (8)
8 l~I
. . .
. . . .
250 MCM
4~ (9)
(9)
8~
10 (10)
--
!iil
10
12
~;
6
8
8
10
12
l ol
(16)
(20)
(22)
(24)
.
.
1
0-00
ooo-oooo
600-700 MCM
750-900 MCM
1000-1250 MCM
1500-2000 MCM
.
.
.
2~
400-s00 '.CM
.
.
.
2
6
.
5
.
.
.
-"
10
12 (19) 14
12 (22) 14 (24) 16
. . . . . .
. . . . . .
3
Not Spec.
2
3
4
5
8
2
3
4
5
8
10
I0
12
16
15
18
21
24
27
9
9
12
14
16
20
22
24
4
5
-
15
18
20
22
26
24
28
32
373-6(b) and (c): Reject
Cl@ 9
SUBMITTER: Ralph H. Lee, Lee ElectrAcal Engineering, Inc.
~ 4 1
Revise as follows:
~pace
for single bend at terminals. Conductors required
to be bent in one bend not exceeding 90° shall require bending
space in accordance with Table 373-6(a). Change(c) to (d)and
add new (c) as follows:
(c) Spacefor additional bends at terminals. Conductors
required to be bent in more than one bend, such as an S-bend
condition, shall be accorded bending space of two times 'that
shown In Table 373-6(a).
SUBSTANTIATION: Table 373-6(a) is properly based on conductors
leaving a terminal, making one 90a bend along the side gutter of
a panelboard cabinet, and exiting from top or bottom of the
cabinet. As such, I t properly specifies the allowance of space
for this bend in accordance with the permitted bending radii of
the varlous-sized wires and conductors as set forth by IPCEA,
that body most knowledgeable about the susceptibility of wires
and cables to the various installation problems.
In the absence of any other table in NEC regarding
termlnal-to-side-wall spacing, this table has been applied
without modification to all terminal sldewall/spacings,
~egardless of the need for additional bends. The great majority
of uses in switches, circuit breakers and similar gear, requires
that two of the three wires be formed into S-bends to accomodate
the separation of terminals and the exit of the conductors,
through a single conduit or bushing. In these many cases, the
double bend must be cramped into the space which is properly
specified for only a single bend. Over-sharp bending of cables
at terminals, and In pressure against wlre insulation are major
results. Both of these are serious sources of failures which
can be responsible for fires.
C
Sln~)le short-time tests of over-sharp bending Just to show " i t
can be done" can never be condoned as reason for retaining this
monstrosity in the Code, any more than short-term testing could
Justify the use of EC aluminum wiring in'residences. Any
Journeyman electrician knows that the biggest problem in
electrical installation Is the crowded termination space,
requiring excessively sharp conductor bending;
this is shown from a questionnaire published a few years ago.
So why, i f Table 373-6(a) spacings are required for their real
intent, single bends, does the Code not require double these
values for double bends?
PANEL RECOI~ENDATION: Reject.
PANEL COGENT: See Panel action on Proposal No. 38.
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
C
1
1 and 2
Delete fine print note from Table 373-6(a) and relocate as FPN
to Table 373-6(b).
SUBSTANTIATION: Supporting comments for Proposal No. 40 and 43
Page 195 of the Preprint for the 1978 National Electrical Code
determines that we are not mainly concerned wlth insulation
damage when bending conductors, but with misaligument of the lay
of the conductor strands which in turn cause excessive heating.
Consequently causing further insulation damage, even f i r e .
Field experience has, for years, been c r i t i c a l of the crowded
bending spaces provided in enclosures containing terminals.
This continual arbitration with industry f i n a l l y came to the
point of a Fact Finding Committee compiling the data that
actually substantiates the long sought extra bending spaces
required to correct these field problems which have caused more
trouble than was actually anticipated by the industry. These
statistics were used for basis of the proposed new,Table
373-6(b).
The installation problems were found not only to exist In the
conductor requiring bends or offsets, but, more consideration
was required for the ones that are directed straight into the
terminals, thus, more bending space for a l ) the conductors in
the enclosures is needed.
PANEL RECOI~ENDATION: Reject.
PANEL COI~ENT: See Panel action on Proposal No. 38.
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
Table 373-6(a) -- Minimum Wire Bending Space at Terminals
and Minimum Width of Wiring Gutters in Inches
AWG
Circular-Mil
Size of Wire
Wires per Terminal
I :l
(20) 16
(26) 18 (26)
. .
. .
Table 373-6(a), 373-6(b),
CMP g
New Table 373-6(b): Reject
SUBMITTER: IdahoChapter IAEI
40 Revise t i t l e of Table 373-6(a) as follows:
~ m
Width of Wiring Gutters in Inches.
Revise (b) and add new Table 373-6(b) as follows:
(b) Wire Bending Space at Terminals. Conductors shall not be
deflected at a terminal unless bending space within a cabinet or
cutout box is provided In accordance with Table 373-6(b).
Conductors in parallel in accordance with Section 310-4 shall be
Judged on the basis of the number of conductors in parallel.
168
373-6(c)-(New)(HOD 1978 NEC): Reject
CMP 9
SUBMITTER: CMP 9
PROPOSAL: 42 AmendSection 373-6 by adding thereto a new
su--Gb-T~ETon (c) as follows:
(c) The provisions of subsections (a) and (b) of this section
apply to conductors bent or deflected no more than once. For
conductor bending space at terminals and width of gutter space
f o r conductors that are bent or deflected more than once, the
gutter or bending space required shall be one and one half times
the value l i s t e d In Table 373-6(a). Present subsection " ( c ) "
w111 become "(d)."
SUBSTANTIATION: We were convinced by the supportlng comment
supplied wlth Proposal No. 39 in the 1978 Preprlnt.
PANEL RECOMMENDATION: Reject.
PANEL COGENT: See Panel action on Proposal No. 38.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
373-10(a): Accept
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
PR'O-~(5~_-T." 43 See the Technical Subcommittee "Recommendations"
un--6-de-~'-t~f~e definition of "Approved for the Purpose" in Artlcle
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" In Article 100.
PANEL RECOMMENDATION: Accept as Revised:
i Delete the words "and shall be approved for the purpose."
VOTEON PANELRECOMMENDATION: Unanimously Affirmative.
I
373-10(c): Reject
CMP 9
SUBMITTER: Patrick J. Fox, St. Louis, MO
PIIIS]IO'S'~-~.
• 44 Changeparagraph to read:
~-~ Nonmetallic Cabinets and Cutout Boxes. Nonmetallic
cabinets and cutout boxes shall be approved for the purpose.
SUBSTANTIATION: This is intended to make the statement
consistent with the statement for metal cabinets and cutout
• boxes and with Section 370-3. To require submittal for approval
of every nonmetallic cabinet and box appears unnecessary i f they
are approved for the purpose.
• This was previously submitted for the 1975 National Electrical
Code and a Task Group was to have studied this proposal change.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present Code wording is necessary until
standards are written.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Cramer.
EXPLANATION OF VOTE:
CRAMER: The existing Section required approval prior to
installation. Approval after installation should suffice.
Sentence should read: "Norm~tallic cabinets shall be suitable
for the environment."
373-11(a)(3); Accept
CMP g
SUBMITTER: TSC-Neminal Voltage
P]TOlIO-~lZ~.'45 Change"600" in last line to "635."
~IATION:
To conform to the method to express maximum
voltage as per, guldellnes developed by the TSC on nominal
voltage.
PANEL RECOMMENDATION: Accept as Revised:
Leave 600 as is, but insert the word "nominal" after "600."
VOTE ON PANELRECOMMENDATION: UnanlmouslyAffirmative.
373-1?-(New): Reject
CMP g
SUBMITTER: SouthwesternSection IAEI
PROPOSAL: 47 Add new section as follows:
~TrJTI'2T-. Equipment On Cabinet Door. No device or other
equipment utilizing electric wiring shall be mounted on or be
supported by any cabinet or panelboard trim, cover or door except where hinged doors designed for the purpose are employed.
SUBSTANTIATION: Switches, pushbuttons, p i l o t lights and similar
• control circuit equipment which might be mounted on a reFnovable
cabinet cover can offer a severe shock hazard to maintenance
personnel. Usually the screws holding the cover in place
provide the equipn~nt grounding, which means that a man removing
the cover has an ungrounded piece of equipment in hls hand.
Furthermore, switches for disconnecting the control circuits are
often within the cabinet, making i t d i f f i c u l t to de-energize the
circuit. I f the cover slips during the process of removal, a
live exposed terminal can be grounded to the side of the
enclosure.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION:Unanlmously Affirmative.
)
373-X:. Reject
CMP 9
SUBMITTER: Ralston W. Calvert, Dept. Bldg. & Safety, City of
P-al~--O'es-ert
PROPOSAL: 48 Add a new paragraph to Article 373 (Installation)
~h-TcTi--s~all say "Cabinets or cut boxes located in wall or other
places, shall not be installed less than two feet nor more than
6 I/2 feet vertically from the ground floor, concrete slab or
roof).
Exception: Cabinets and cut out boxes located in vaults or
other approved locations."
SUBSTANTIATION:
I . An overcurrent protective device being used to protect an
air conditioning unit. The OPD enclosure was located one inch
above the ground, the cover of the enclosure hinged on top.
When the cover was opened, the manufacturer's specifications and
the directory could not be read. I had to lie on my stomach to
inspect the equipment and on my back to read the manufacturer's
specifications and directory...(and that's when the sprinkling
system came on).
2. A sub-panel located three inches above a patio concrete
slab. To inspect the installation, I had to lie on the slab as
the cover was hinged on top. I t was also d i f f i c u l t for the
owner to see the circuit breakers, as the cover partially
blocked his view. Whenever the patio was hosed off, which was
often, the enclosure was drenched with water.
3. An overcurrent protective device and its enclosure was
located on a f l a t roof. The enclosure was two inches above the
roof. To inspect the job or to work on the equipment, a most
d i f f i c u l t and tiring position must be maintained. A man wearing
glasses would be in a dangerous position, due to the required
t i l t of his head, leading to poor vision, thereby contributing
to a possible accident.
PANEL RECOMMENDATION: Reject.
PJ~NE[ COMMENT: Supporting comment is not consistent with the
Proposal.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COGENT ON VOTE:
CRAMER: I agree with the reject but feel.~hat the reason is
that this is getting into design considerations and away from
safety. To attempt to set limits that universally apply to
every installation is very d i f f i c u l t . The inspecting authority
can judge the equipment in accordance with Section 110-3 and has
the power to reject.
373-12-{New): Reject
CMP 9
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
]~ffO-P'O~-~ 46 Add a new section as follows:
~7"c[zT'ZT- . Equipment on Cabinet Door. No device or other
equipment utilizing electric wiring shall be mounted on or be
supported by any cabinet or panelboard trim, cover or door except where hinged doors designed for the purpose are employed.
SUBSTANTIATION: Switches, pushbuttons, pilot lights and similar
control circuit equipment which might be mounted on a removable
cabinet cover can offer a severe shock hazard to maintenance
personnel. Usually the screWs holding the cover in place
provide the equipment grounding, which means that a man removing
the cover has an ungrounded piece of equipment in his hand.
Furthermore, switches for disconnecting the control circuits are
often within the cabinet, making i t d i f f i c u l t to de-energize She
circuit. I f the cover slips during the process of ren~)val, a
live exposed terminal can be grounded to the side of the
enclosure.
PANEL RECOf~ENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 380 -- SWITCHES
380-2(b): Reject
~
CMP 9
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
PITOIR)S
'A
' -L-~." 49 Revise as follows:
~ r
switches nor circuit breakers shall disconnect the
grounded conductor of a circuit.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.' In many instances, this usage is
not only gra~matically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Reject.
PANEL CO~g4ENT: Panel feels subject is adequately covered.
VOTEON PANELRECOV~ENDATION: UnanimouslyAffirmative.
380-2(b), Exception No. 1: Reject
CMP g
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
PROPOSAL: 50 Revise as follows:
~either
the switch or the circuit breaker etc.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.' In many instances, this usage is
not only grammatically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
169
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "approved for the purpose" and add the word
"Approved" at the the beginning of the sentence.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Chapter 9 Table l, Note 5: Accept
CMP 8
SUBMITTER! CMP 8
!aITOPOS7
' ~-~•. 175A Add to Note 5 the word "maximum" before
~ e . "
Add FPN after Note 5 to read:
Table l is based on common conditions of proper cabling and
alignment of conductors where the length of the pull and the
number of bends are within reasonable limits. I t should be
recognized that for unusual conditions a larger size conduit or
a lesser conduit f i l l should be considered.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 374 -- AUXILIARY GUTTERS
374-9(f)-(New): Reject
CMP 8
SUBMITTER: S. D. Mauney, Carolina Power & Light Company
PHUPU~AL: 173 Add new (f) as follows:
-~here
an auxiliary gutter is to contain bends or taps to
an electric supplier's service conductors larger than No. i AWG,
its width at the cover shall be at least 200 percent of that
given in Table 373-6(a) and its minimum depth from cover to back
shall be 100 percent of the width given in Table 373-6(a).
Where the size of the supplier's service conductors is not
readily available, the conductor size may be calculated as the
equivalent size of the largest aluminum conductors with a 75°C
ampacity rating equal to the sum of the service overcurrent
devices tapped to the supplier's service conductors. In the
table, "Wires per terminal" is to be used to indicate the number
of the supply service conductors in parallel per phase.
SUBSTANTIATION The required width of the auxiliary gutters used
on surv~ces for taps to several or more meter or service
equip(nent cabinets is inadequate dn many instances. No stated
minmum depth is required. Due to the stiffness and size of the
service conductors and to the large size of taped connectors,
the connections are under pressure from adjacent conductors,
connectors, and the gutter cover.
Even the best tapes are subject to abrasion due to expansion
and contraction of the conductors with the load cycle. They
also soften due to heat. Shorts occur when the tape is abraded
away or softened abnormally. More space will help connections
to be positioned away from each other and from the cover. The
proposed size is minimum. Experience may indicate that larger
sizes may be needed.
More space is also needed as/additional taps are made to the
service conductors. This is ~specially true of commercial
buildings with movable walls where the number, size, and loads
of the occupancies is ever changing. Space is also needed when
loads are checked with cllp-on ammeters, etc.
Increasing the size of service gutters is already often done
by some electricians Who realize that the savings in
installation labor and maintenance easily offset the additional
material cost involved.
Safety is involved anytime a f i l l e d gutter is opened for
inspection or to make changes as removing the cover allows the
spring action of the cramped
conductors to come into play. Closing the cover puts additional
pressure on the connections.
PANEL RECOI~4ENDATION: Reject.
PANEL COMMENT: Already covered by Section 374-9(d). Training
space is being studied by Panel 9.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Table l , Chapter g: Reject
CMP 8
SUBMITTER: CMP 8
175B In the 3 conductor column, delete 40 (percent
~ d
insert 33 (percent f i l l ) for both lead covered and
non-lead covered conductors.
SUBSTANTIATION: There exists a l ~ t t l e understood problem of
"jam ratio" where only three conductors are installed in a
conduit. This is ratio of the diameters of the conduit and the
single conductor (D/d). This ratio is c r i t i c a l between 2.5 and
3.0 where the conductors are not triplexed. At a ratio of 3.0
and greater, the conduit is wider than the sum of the 3'
conductors which prevents Jamming.
At this ratio the area of the conductors is 3d2~
The area of the conduit is (3d)2 = 9d2~
L
~
---I-F i l l = 3/9 = 33 1/3 percent.
At 40 percent f i l l the maximum allowable conductors are always
in the c r i t i c a l Jam ratio.
PANEL REC~NDATION: Reject.
PANtL ~UMM~NI: UMP ~ would prefer to withdraw the Proposal and
I t is rejected on that basis.
VOTE ON PANEL RECOMMENDATION: Unanimously A f f i r m a t i v e . .
CMP 8
Chapter 9, Table l , Note 6: Reject
SUBMITTER: CMP 8
PROPOSAL: I75C Add a new Note 6 as follows:
~ i l l
shall be permitted for triplexed conductors."
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel Comment on Proposal No. 175B.
VOTE ON PANELRECOI¢MENDATION: Unanimously Affirmative.
Table 1, Chapter 9: Reject
CMP 8
SUBMITTER: Joseph M. Ostrlhonsky, Sioux City, IA
PROPOSAL:,176 I suggest that the number of wires that is
a-lT6~--d-in 1/2 inch and 3/4 inch pipe be reduced to half. The
wire I'm talking about is TW, THHN, THWN, sizes #12, #14, and
#10. As an alternate, they would change the 40 percent f i l l to
60 percent f i l l based on individual diameters.
SUBSTANTIATION: I f you have had any experience at a l l , you will
know that is I t very d i f f l c u l t to pull, say 9-12 inch TW wires
into a piece of 1/2 inch conduit. I t is almost impossible i f
you havetwo go° bends in the conduit. This Js why I think they
should reduce the number of wires or else change the percent
f i l l of the conduit.
PANEL RECOMMENDATION: Reject.
PANEL CL)f~ENI: ine "conduit f i l l tables are based on the concept
that a safe practical.conduit f i l l percentage is one in which
the diameter of a circle circumscribed around the assembled
conductors would approximate 75 percent of the conduit
diameter. The net area of the conductors within this
theoretical circle approximates 40 percent f i l l .
The Code establishes a 40 percent maximum conduit f i l l .
The
Code also establishes a maximum of four quarter bends (360
degrees t o t a l ) . The Code does not establish a maximum length of
pull. The allowable length of a pull is contingent on a number
of factors including but not limited to: I) maximum allowable
conductor tension, 2) the plane of the bends (whether they are
horizontal or vertical and whether any are reverse bends), 3)
proper cabling of the conductors, 4) the weight of the cable, 5)
the coefflcent of f r i c t i o n between the conductors and the
conduit, and 6) sidewall pressure.
Since the Code is not a design manual Judgement must be used
in studying all of these "factors on whether.to use the maximum
f i l l and the maximum number of bends to accommodate the maximum
length of pull. Proper cabling of a large number of conductors
is of extreme importance in such a Judge~nt.
VOTE ON PANELRECOI~ENDATION: UnanimouslyAffirmative.
CHAPTER 9 -- TABLES AND EXAMPLES
Chapter 9, A. Tables, Note 2: Reject
CMP 8
SUBMITTER: Peter Pollak, The Aluminum Association
I~OFOSAL-~. 174 In the second sentence of Note 2, replace
~-~ted
or bare)" with "(insulated, bare or compact)."
SUBSTANTIATION: Question arises in the f i e l d regarding the
selection of the proper conduit size for the application.
Makes clearer the fact that the actual dimensions of compact
equipment grounding conductor shall be used in the calculation
of conduit f i l l .
PANEL RECOI~4ENDATION: Reject.
PANEL COMMENT: Proposal is pcimarily a design consideration.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 14.
NEGATIVE: Durham.
EXPLANATION OF VOTE:
DURflAM: Panel action is not consistent with Proposal No. 175.
Chapter 9., A. Tables, Note 4: Accept
CMP 8
SUBMITTER: Peter Po'llak, The Aluminum Association
Ii PRUPU~AL 175 In Note 4 insert "such as compact
or
=
~ductor
cables," after "Chapter 9 . '
' SUBSTANTIATION: Question arises in the f i e l d regarding the
selection of the proper conduit size for the application.
Makes clear the fact that actual dimensions of compact or
multlconductor cables shall be used in the calculation of
condu'i t f i l l .
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
158
373-6(c)-(New)(HOD 1978 NEC): Reject
CMP 9
SUBMITTER: CMP 9
PROPOSAL: 42 AmendSection 373-6 by adding thereto a new
su--Gb-T~ETon (c) as follows:
(c) The provisions of subsections (a) and (b) of this section
apply to conductors bent or deflected no more than once. For
conductor bending space at terminals and width of gutter space
f o r conductors that are bent or deflected more than once, the
gutter or bending space required shall be one and one half times
the value l i s t e d In Table 373-6(a). Present subsection " ( c ) "
w111 become "(d)."
SUBSTANTIATION: We were convinced by the supportlng comment
supplied wlth Proposal No. 39 in the 1978 Preprlnt.
PANEL RECOMMENDATION: Reject.
PANEL COGENT: See Panel action on Proposal No. 38.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
373-10(a): Accept
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
PR'O-~(5~_-T." 43 See the Technical Subcommittee "Recommendations"
un--6-de-~'-t~f~e definition of "Approved for the Purpose" in Artlcle
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" In Article 100.
PANEL RECOMMENDATION: Accept as Revised:
i Delete the words "and shall be approved for the purpose."
VOTEON PANELRECOMMENDATION: Unanimously Affirmative.
I
373-10(c): Reject
CMP 9
SUBMITTER: Patrick J. Fox, St. Louis, MO
PIIIS]IO'S'~-~.
• 44 Changeparagraph to read:
~-~ Nonmetallic Cabinets and Cutout Boxes. Nonmetallic
cabinets and cutout boxes shall be approved for the purpose.
SUBSTANTIATION: This is intended to make the statement
consistent with the statement for metal cabinets and cutout
• boxes and with Section 370-3. To require submittal for approval
of every nonmetallic cabinet and box appears unnecessary i f they
are approved for the purpose.
• This was previously submitted for the 1975 National Electrical
Code and a Task Group was to have studied this proposal change.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present Code wording is necessary until
standards are written.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Cramer.
EXPLANATION OF VOTE:
CRAMER: The existing Section required approval prior to
installation. Approval after installation should suffice.
Sentence should read: "Norm~tallic cabinets shall be suitable
for the environment."
373-11(a)(3); Accept
CMP g
SUBMITTER: TSC-Neminal Voltage
P]TOlIO-~lZ~.'45 Change"600" in last line to "635."
~IATION:
To conform to the method to express maximum
voltage as per, guldellnes developed by the TSC on nominal
voltage.
PANEL RECOMMENDATION: Accept as Revised:
Leave 600 as is, but insert the word "nominal" after "600."
VOTE ON PANELRECOMMENDATION: UnanlmouslyAffirmative.
373-1?-(New): Reject
CMP g
SUBMITTER: SouthwesternSection IAEI
PROPOSAL: 47 Add new section as follows:
~TrJTI'2T-. Equipment On Cabinet Door. No device or other
equipment utilizing electric wiring shall be mounted on or be
supported by any cabinet or panelboard trim, cover or door except where hinged doors designed for the purpose are employed.
SUBSTANTIATION: Switches, pushbuttons, p i l o t lights and similar
• control circuit equipment which might be mounted on a reFnovable
cabinet cover can offer a severe shock hazard to maintenance
personnel. Usually the screws holding the cover in place
provide the equipn~nt grounding, which means that a man removing
the cover has an ungrounded piece of equipment in hls hand.
Furthermore, switches for disconnecting the control circuits are
often within the cabinet, making i t d i f f i c u l t to de-energize the
circuit. I f the cover slips during the process of removal, a
live exposed terminal can be grounded to the side of the
enclosure.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION:Unanlmously Affirmative.
)
373-X:. Reject
CMP 9
SUBMITTER: Ralston W. Calvert, Dept. Bldg. & Safety, City of
P-al~--O'es-ert
PROPOSAL: 48 Add a new paragraph to Article 373 (Installation)
~h-TcTi--s~all say "Cabinets or cut boxes located in wall or other
places, shall not be installed less than two feet nor more than
6 I/2 feet vertically from the ground floor, concrete slab or
roof).
Exception: Cabinets and cut out boxes located in vaults or
other approved locations."
SUBSTANTIATION:
I . An overcurrent protective device being used to protect an
air conditioning unit. The OPD enclosure was located one inch
above the ground, the cover of the enclosure hinged on top.
When the cover was opened, the manufacturer's specifications and
the directory could not be read. I had to lie on my stomach to
inspect the equipment and on my back to read the manufacturer's
specifications and directory...(and that's when the sprinkling
system came on).
2. A sub-panel located three inches above a patio concrete
slab. To inspect the installation, I had to lie on the slab as
the cover was hinged on top. I t was also d i f f i c u l t for the
owner to see the circuit breakers, as the cover partially
blocked his view. Whenever the patio was hosed off, which was
often, the enclosure was drenched with water.
3. An overcurrent protective device and its enclosure was
located on a f l a t roof. The enclosure was two inches above the
roof. To inspect the job or to work on the equipment, a most
d i f f i c u l t and tiring position must be maintained. A man wearing
glasses would be in a dangerous position, due to the required
t i l t of his head, leading to poor vision, thereby contributing
to a possible accident.
PANEL RECOMMENDATION: Reject.
PJ~NE[ COMMENT: Supporting comment is not consistent with the
Proposal.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COGENT ON VOTE:
CRAMER: I agree with the reject but feel.~hat the reason is
that this is getting into design considerations and away from
safety. To attempt to set limits that universally apply to
every installation is very d i f f i c u l t . The inspecting authority
can judge the equipment in accordance with Section 110-3 and has
the power to reject.
373-12-{New): Reject
CMP 9
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
]~ffO-P'O~-~ 46 Add a new section as follows:
~7"c[zT'ZT- . Equipment on Cabinet Door. No device or other
equipment utilizing electric wiring shall be mounted on or be
supported by any cabinet or panelboard trim, cover or door except where hinged doors designed for the purpose are employed.
SUBSTANTIATION: Switches, pushbuttons, pilot lights and similar
control circuit equipment which might be mounted on a removable
cabinet cover can offer a severe shock hazard to maintenance
personnel. Usually the screWs holding the cover in place
provide the equipment grounding, which means that a man removing
the cover has an ungrounded piece of equipment in his hand.
Furthermore, switches for disconnecting the control circuits are
often within the cabinet, making i t d i f f i c u l t to de-energize She
circuit. I f the cover slips during the process of ren~)val, a
live exposed terminal can be grounded to the side of the
enclosure.
PANEL RECOf~ENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 380 -- SWITCHES
380-2(b): Reject
~
CMP 9
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
PITOIR)S
'A
' -L-~." 49 Revise as follows:
~ r
switches nor circuit breakers shall disconnect the
grounded conductor of a circuit.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.' In many instances, this usage is
not only gra~matically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Reject.
PANEL CO~g4ENT: Panel feels subject is adequately covered.
VOTEON PANELRECOV~ENDATION: UnanimouslyAffirmative.
380-2(b), Exception No. 1: Reject
CMP g
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
PROPOSAL: 50 Revise as follows:
~either
the switch or the circuit breaker etc.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.' In many instances, this usage is
not only grammatically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
169
380-2(b), Exception No. 2: Reject
CMP 9
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
]~TO-FO-S~A[~•-. 51 Revise as follows:
~here either the switch or the circuit breaker etc.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.
In many instances, this usage is
not only grammatically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
380-3: Accept
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
52 See the Technical Subcommittee "Recommendations"
un-~-d-e~"the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Revise the f i r s t sentence of 380-3 to read: "Switches and
circuit breakers shall be of the externally operable type
mounted in an enclosure listed for the intended use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COf~ENT ON VOTE:
BARKER: For listing, who determines the intended use?
380-4: Reject
CMP 9
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
53 Revise as follows:
~rO'Zir~-~et Locations. Where elther a switch orj a circuit
breaker (or both) is installe~ in a wet location shall be
enclosed in a weather proof enclosure which complies with
Section 373-2.
Note: Wet Iocation-definitioo includes outside buildings and
exposed to the weather. Section 373-2 includes both cabinets
and enclosures.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.' In many instances, this usage is
not only grammatically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.' In many instances, this usage is
not only grammatically incorrect, but the meaning is not clear.
PANEL RECOI~4ENDATION: Accept.
'
PANEL COMMENT: Sane as Proposal No. 56.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
CRAMER: Samecomment as Proposal No. 56.
380-11: Reject
CMP 9
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
PITOPOS
'~
' [L-T." 58 Add a sentence as follows:
The supply conductors of single circuit breakers in non-bussed
enclosures shall be connected to the terminals nearest the on
position of the operating handle.
SUBSTANTIATION: The proposed connection configuration for
circuit breakers in enclosures has been an industry standard for
EXO switches for many years. Accordingly, electricians assume
that the load conductors are connected nearest the off
position. The purpose of this requirement has nothing to do
with the operation of a circuit breaker as i t will function
properly connected either way. Workmenhave been injured when
they attempted to remove what they thought was a de-energlzed
load conductor because i t was connected to the load side, (near
the off side), and i t turned gut to be a line conductor. This
requirmentprovldes a necessary safety precaution for
maintenance personnel and equipment installers.
PANEL RECOMMENDATION: Reject.
PANEL CO~4ENT: No significant contribution to safety would
result. This Proposal would lend i t s e l f to a false sense of
security.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
3BO-13(a) and (b): Accept
CMP g
SUBMITTER: TSC-Nominal Voltage
~ 5 9
In the second lines of (a) and (b) change "600"
to ~ "
SUBSTANTIATION: To conform to the method to express maximum
voltage as per guidelines developed by the TSC on nominal
voltage.
PANEL RECOMMENDATION: Accept as Revised:
380-13(a) No change. Insert the word "nominal" after 250 volts
and after 600 volts in Section (b).
PANEL COMMENT: The voltages expressed are rated voltages.
°
~RECOMMENDATION:
UnanimouslyAffirmative.
COMMENTON VOTE:
CRAMER: I agree with the action. The reason for the action
is that the voltage expressed in (a) are rated voltages whereas
in (b) voltages are nominal.
380-6(b): Accept
CMP 9
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
54 Revise the last sentence as follows:
~ t h e
throw is vertical, a locking device shall be
provided to hold the blades i n the open p o s i t i o n when sO set.
'SUBSTANTIATION: NFPA70-1978 uses the word 'or"loosely without
the correlation of 'either.' In many instances, this usage is
not only grammatically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: We agree with the proposal, although his
substantiation is not clear.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
380-13(b): Accept
CMP g
SUBMITTER: TSC-Approvedfor the Purpose
Pl~-OIR~-~.'60 See the Technical Subcemmittee "Recon~nendations"
un-n-d~-~-t-~e definition of "Approved for the Purpose" in A r t i c l e
I00.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Substitute the word "listed" for "approved."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
380-6(b): Accept
CMP 9
SUBMITTER: SouthwesternSection IAEI
55 Revise the last sentence to read:
~ t h e
throw is vertical, a locking device shall be
provided to hold the blades in the open position when so set.
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
correlation of 'either.' In many instances, this usage is not
only gramatically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: Sameas Proposal No. 54.. We agree with the
proposal, although his substantiation is not clear.
VOTE ON PANELRECOMMENDATION: UnanlmouslyAffirmative.
380-14ia)(2): Reject
CMP g
SUBMITTER: J.J. Kark, National Electrical Manufacturers
~ o n
PROPOSAL: 61 Revise to read:
--'-T~Tungsten-filament lamp loads not exceeding the ampere
rating of the switch at 120 volts "for single-pole, double-pole,
3-way, and 4-way switches."
SUBSTANTIATION: The present wording does not recognize that AC
type switches are designed for other than lighting loads.
Examples of switch actions not requiring tungsten test include:
3 position switches, momentary contact switches and maintained
contact switches. These are used in Start-Stop circuits,
Ralse-Lower circuits, etc. where the tungsten requirements are
not applicable. The des!gn parameters of these type switches
differ greatly from those used for tungsten loads.
Underwriters Laboratories interprets the present code wording
to require tungsten tests on all AC switches regardless of end
use. The requested change would allow manufacturers to design
switch mechanisms to optimum performance as required by the end
380-8(a): Accept
CMP g
SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI
. ~
56 Revise the f i r s t sentence by adding "so" between
T~--aITl)e" and "located."
SUBSTANTIATION: NFPA70-1978 uses the word 'or' loosely without
the correlation of 'either.' In many instances, this usage is
not only grammatically incorrect, but the meaning is not clear.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
CRAMER: I agree because he's grammatically correct although
his substantiation is no good.
use.
PANEL RECOI~dENDATION: Reject.
:
e anel does not agree with the supporting
comment. The switches mentioned in the substantiation could be
used for tungsten loads.
VOTEON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Burniston, Demlng.
EXPLANATION OF VOTE:
BURNISTON: As the proposal indicates, the concern Is with
3BO-B(a): Accept
CMP 9
SUBMITTER: SouthwesternSection IAEI
. ~
57 Revise the f i r s t sentence by adding "so" between
•~
and located.
J
I
170
/
384-1. Scope. This A r t i c l e covers (1) a l l switchboards,
panelboards, d i s t r i b u t i o n boards, and LV swttchgear
(metal-enclosed low-voltage power c i r c u i t breaker switchgear)
i n s t a l l e d f o r the control of - - - power c i r c u i t s .
Exception: (No change).
Add (now) 384-X:
384-X. LV Switchgear (Metal-Encased Low-Voltage Power C i r c u i t
Breaker Switchgear). An assembly of one or more. individual
enclosures containing the follOwing equipment as required:
Low-voltage po~cer c i r c u i t breakers (fused or unfused); .bare bus
and connections; instrument and control power transformers,
instruments, meters, and relays, control wiring and accessory
devices.
The low-voltnge power c i r c u i t breakers a r e contained in
individual grounded metal con~artments and controlled either
ramotely or from the f r o n t of the enclosure. The c i r c u i t
breakers may be stationary or removable type; when of removable
type, mechanical Interlocks are provided to ensure a proper and
safe operating sequence.
LV swttchgear assemblies are t o t a l l y enclosed with no exposed
l i v e parts.
Revise 384-2:
384-2. Other A r t i c l e s . Switches, c i r c u i t breakers, and
overcurrent de, ices used on switchboards, panelboards,
d i s t r i b u t i o n boards, or LV swltchgear, and t h e i r enclosures,
shall comply . . . . . . . that apply. Switchboards . . . . . . through
517.
Revise 384-3(a):
(a) Conductors and busbars on a power switchboard, panelboard,
control board, or LV swttchgear shall be so located . . . . . .
place. Other than the required . . . . . . in a v e r t i c a l section of
a power switchboard or LV switchgear shall be located In that
section. Barriers shall be placed in a11 service power
switchboards and LV swttchgear that w i l l isolate . . . . remainder
of the equtp~nt.
Revise 384-3(c):
( c ) Each power switchboard, LV swttchgear, power switchboard
or LV swttchgear section, or panelboard, t f used . . . . . . to the
equipment frame; All sections of a power switchboard or LV
switchgear shall be bonded . . . . . . Table 250-95.
Revise 384-3(d):
(d) Load terminals in power switchboards, panelboards, and LV
switchgear shall be . . . . . . connections.
Revise 384-3(e):
(el On a power switchboard, panelboard, or LV switchgear
supplied from a . . . . . . marked.
Revise 383-3(f):
(f) The phase arrangement - - z - - - the front of the power
switchboard, panelboard, or LV switchgear.' The B phase
. . . . . . . . . . . ground. Other busbar . . . . . . marked.
Revise Part A Title:
A. Switchboards and LV switchgear
Revlse384-7:
384-7. Clearance from Ceiling. A space -~ . . . . of any
switchboard or LV switchgear . . . . . . c e i l i n g .
Exception No. 1: Where a . . . . . the switchboard or
LV swltchgear and the c e i l i n g .
Excepttoh No. 2: T o t a l l y enclosed switchboards and
LV swltchgear.
Revise 384-8:
384-8. Clearances Around Switchboards and LV Switchgear.
Clearances around switchboards and LV switchgear shall . . . . .
Section 110-16.
Revise 384-10:
384-10. Clearances for Conductors Entering Bus Enclosures.
Where conduits or other raceways enter a power switchboard, or
LV switchgear, floor standing panelboard, . . . . . . enclosure. The
wiring . . . . . . obstructions. The conduit . . . . . . enclosure.
other than standard single pole, double pole, 3-way and 4-way
switches used in lighting control c i r c u i t s . The specific
switches covered by this proposal are a variety of either
maintained or momentary contact switches of one, two or three
position single or double pole. The loads being controlled are
either resistance or inductive loads, but not tungsten loads.
(The Panel was supplied the more typical diagrams.)
The Code has been interpreted as requiring all genera]
switches to be tungsten rated, which i n h i b i t s design.
C l a r t f l c a t t o n is required to exempt these special use AC
switches to a l l o w the use of designs which maximize the
performance on the intended loads.
DEMING: The switches mentioned in the substantiation could be
marked'"Not suitable f o r tungsten loads."
There are many instances within the Code where a product
misused or used f o r the wrong purpose could create a hazardous
condition.
380-14(a)(4): Accept
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
62 See the technical Subcommittee "Recommehdations"
un--n-d'e'r't~Te definition of ~Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Change 380-14(a)(4) to 380-14(c) and revise to read as
follows: "(c) CO/ALR Snap Switches. Snap switches rated 20
amperes or less directly connected to aluminum conductors shall
be listed and marked CO/ALR."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Burnlston.
EXPLANATION OF VOTE:
BURNISTO~I: ~MA has no objection to the Panel Recemmendatlon
to revise the text of Section 380-14(a)(4), but feels that
relocating this Section to now Section 380-14(c) goes beyond the
Panel's intent.
The Pane] did not intend to imply that CO/ALR snap switches
are suitable for use on other than AC circuits wfien connected to
aluminum conductors, nor that their suitability should go beyond
those uses covered under Section 380-14(a). The location of the
'recommended text should remain as Section 380-14(a)(4).
380-16: Accept
CMP 9
SUBMITTER: TSC-Nominal Voltage
~ 6 3
' Revise the end of the second llne and beginning
o--'f'-TF~rF-d line to read "knife switch rated600 volts, etc."
SUBSTANTIATION: To conform to the method to express rated
voltage of equipment as per the guideline developed by the TSC
on nominal voltage.
PANEL RECOMMENDATION: Accept as Revised:
I Changethe word "switch" to "switches."
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
380-17, Exceptlon-(New): Reject
CMP 9
SUBMITTER: W. Crelghton Schwan, Hayward, CA
64 Add a new exception as follows:
--~lon:
Fuses factory assembled in parallel, as permitted
in the Exception to Section.240-8.
SUBSTANTIATION: The proposed revision will remove a conflict
from.the Code. High voltage fuses have long been recognized in
parallel when assembled in a commonmounting means designed for
the purpose (see Section 710-21(b)(1)).
Section 240-8 was revised in the 1978 NEC to recognize fuses
factory assembled in parallel. I f fuses in parallel are
recognized by the Code, the sameCode must a11ow a switch to
accemodate them.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 65.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
(Table)
.................................
.................................
Revise 384-11:
384-11. Grounding Power Switchboards and LV Switchgear Frames.
Power switchboard or LV switchgear frames and . . . . . . grounded. •
Exception: Frames of direct-current single-polarity power
switchboards and LV switchgear shall not . . . . . . insulated.
Revise 384,12:
384-12. Grounding of Instruments, Relays, Meters, and
Instrument transformers onSwltchboards and LV Switchgear.
Instruments, . . . . . . located on switchboards or LV swltchgear
shall be . . . . . . through 250-125.
SUBSTANTIATION: Article 384 does not presently include
reference to LV switchgear which is also a product designed for
the control of light and power circuits. This omission causes
confusion and misunderstandlngabout the requirements for the
installatlon of LV switchgear for this purpose. The proposed
addition of 384-X and reference to LV switchgear in the other
sectlons of Article 384 will clarify these requirements.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The panel feels the scope covers switchgear.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Burniston.
COMMENTON VOTE:
ECKARDT: TO ellmninate the confusion a sentence could be
added, to Section 384-I namely "Where switchboards are mentioned
380-17-FPN (NEW): Accept
CMP 9
SUBMITTER: Idaho Chapter IAEI
~ 6 5
Add a FPN to 380-17 to read: See 240-8,
~'~n.
SUBSTANTIATION: For the purpose of better correlation in the
field.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative;
Article 384: Reject
CMP 9
SUBMITTER: J.J. Kark, National Electrical Manufacturers Assn.
~ 6 6
ReviseArticle 384 to also specify LV switchgear
~nclosed
low-voltage power circuit breaker switchgear).
Revise Article Title: SWITCHBOARDS,PANELBOARDS,AND LV
SWITCHGEAR.
Revise 384-1:
171
/
384-1. Scope. This A r t i c l e covers (1) a l l switchboards,
panelboards, d i s t r i b u t i o n boards, and LV swttchgear
(metal-enclosed low-voltage power c i r c u i t breaker switchgear)
i n s t a l l e d f o r the control of - - - power c i r c u i t s .
Exception: (No change).
Add (now) 384-X:
384-X. LV Switchgear (Metal-Encased Low-Voltage Power C i r c u i t
Breaker Switchgear). An assembly of one or more. individual
enclosures containing the follOwing equipment as required:
Low-voltage po~cer c i r c u i t breakers (fused or unfused); .bare bus
and connections; instrument and control power transformers,
instruments, meters, and relays, control wiring and accessory
devices.
The low-voltnge power c i r c u i t breakers a r e contained in
individual grounded metal con~artments and controlled either
ramotely or from the f r o n t of the enclosure. The c i r c u i t
breakers may be stationary or removable type; when of removable
type, mechanical Interlocks are provided to ensure a proper and
safe operating sequence.
LV swttchgear assemblies are t o t a l l y enclosed with no exposed
l i v e parts.
Revise 384-2:
384-2. Other A r t i c l e s . Switches, c i r c u i t breakers, and
overcurrent de, ices used on switchboards, panelboards,
d i s t r i b u t i o n boards, or LV swltchgear, and t h e i r enclosures,
shall comply . . . . . . . that apply. Switchboards . . . . . . through
517.
Revise 384-3(a):
(a) Conductors and busbars on a power switchboard, panelboard,
control board, or LV swttchgear shall be so located . . . . . .
place. Other than the required . . . . . . in a v e r t i c a l section of
a power switchboard or LV switchgear shall be located In that
section. Barriers shall be placed in a11 service power
switchboards and LV swttchgear that w i l l isolate . . . . remainder
of the equtp~nt.
Revise 384-3(c):
( c ) Each power switchboard, LV swttchgear, power switchboard
or LV swttchgear section, or panelboard, t f used . . . . . . to the
equipment frame; All sections of a power switchboard or LV
switchgear shall be bonded . . . . . . Table 250-95.
Revise 384-3(d):
(d) Load terminals in power switchboards, panelboards, and LV
switchgear shall be . . . . . . connections.
Revise 384-3(e):
(el On a power switchboard, panelboard, or LV switchgear
supplied from a . . . . . . marked.
Revise 383-3(f):
(f) The phase arrangement - - z - - - the front of the power
switchboard, panelboard, or LV switchgear.' The B phase
. . . . . . . . . . . ground. Other busbar . . . . . . marked.
Revise Part A Title:
A. Switchboards and LV switchgear
Revlse384-7:
384-7. Clearance from Ceiling. A space -~ . . . . of any
switchboard or LV switchgear . . . . . . c e i l i n g .
Exception No. 1: Where a . . . . . the switchboard or
LV swltchgear and the c e i l i n g .
Excepttoh No. 2: T o t a l l y enclosed switchboards and
LV swltchgear.
Revise 384-8:
384-8. Clearances Around Switchboards and LV Switchgear.
Clearances around switchboards and LV switchgear shall . . . . .
Section 110-16.
Revise 384-10:
384-10. Clearances for Conductors Entering Bus Enclosures.
Where conduits or other raceways enter a power switchboard, or
LV switchgear, floor standing panelboard, . . . . . . enclosure. The
wiring . . . . . . obstructions. The conduit . . . . . . enclosure.
other than standard single pole, double pole, 3-way and 4-way
switches used in lighting control c i r c u i t s . The specific
switches covered by this proposal are a variety of either
maintained or momentary contact switches of one, two or three
position single or double pole. The loads being controlled are
either resistance or inductive loads, but not tungsten loads.
(The Panel was supplied the more typical diagrams.)
The Code has been interpreted as requiring all genera]
switches to be tungsten rated, which i n h i b i t s design.
C l a r t f l c a t t o n is required to exempt these special use AC
switches to a l l o w the use of designs which maximize the
performance on the intended loads.
DEMING: The switches mentioned in the substantiation could be
marked'"Not suitable f o r tungsten loads."
There are many instances within the Code where a product
misused or used f o r the wrong purpose could create a hazardous
condition.
380-14(a)(4): Accept
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
62 See the technical Subcommittee "Recommehdations"
un--n-d'e'r't~Te definition of ~Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Change 380-14(a)(4) to 380-14(c) and revise to read as
follows: "(c) CO/ALR Snap Switches. Snap switches rated 20
amperes or less directly connected to aluminum conductors shall
be listed and marked CO/ALR."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Burnlston.
EXPLANATION OF VOTE:
BURNISTO~I: ~MA has no objection to the Panel Recemmendatlon
to revise the text of Section 380-14(a)(4), but feels that
relocating this Section to now Section 380-14(c) goes beyond the
Panel's intent.
The Pane] did not intend to imply that CO/ALR snap switches
are suitable for use on other than AC circuits wfien connected to
aluminum conductors, nor that their suitability should go beyond
those uses covered under Section 380-14(a). The location of the
'recommended text should remain as Section 380-14(a)(4).
380-16: Accept
CMP 9
SUBMITTER: TSC-Nominal Voltage
~ 6 3
' Revise the end of the second llne and beginning
o--'f'-TF~rF-d line to read "knife switch rated600 volts, etc."
SUBSTANTIATION: To conform to the method to express rated
voltage of equipment as per the guideline developed by the TSC
on nominal voltage.
PANEL RECOMMENDATION: Accept as Revised:
I Changethe word "switch" to "switches."
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
380-17, Exceptlon-(New): Reject
CMP 9
SUBMITTER: W. Crelghton Schwan, Hayward, CA
64 Add a new exception as follows:
--~lon:
Fuses factory assembled in parallel, as permitted
in the Exception to Section.240-8.
SUBSTANTIATION: The proposed revision will remove a conflict
from.the Code. High voltage fuses have long been recognized in
parallel when assembled in a commonmounting means designed for
the purpose (see Section 710-21(b)(1)).
Section 240-8 was revised in the 1978 NEC to recognize fuses
factory assembled in parallel. I f fuses in parallel are
recognized by the Code, the sameCode must a11ow a switch to
accemodate them.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 65.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
(Table)
.................................
.................................
Revise 384-11:
384-11. Grounding Power Switchboards and LV Switchgear Frames.
Power switchboard or LV switchgear frames and . . . . . . grounded. •
Exception: Frames of direct-current single-polarity power
switchboards and LV switchgear shall not . . . . . . insulated.
Revise 384,12:
384-12. Grounding of Instruments, Relays, Meters, and
Instrument transformers onSwltchboards and LV Switchgear.
Instruments, . . . . . . located on switchboards or LV swltchgear
shall be . . . . . . through 250-125.
SUBSTANTIATION: Article 384 does not presently include
reference to LV switchgear which is also a product designed for
the control of light and power circuits. This omission causes
confusion and misunderstandlngabout the requirements for the
installatlon of LV switchgear for this purpose. The proposed
addition of 384-X and reference to LV switchgear in the other
sectlons of Article 384 will clarify these requirements.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The panel feels the scope covers switchgear.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Burniston.
COMMENTON VOTE:
ECKARDT: TO ellmninate the confusion a sentence could be
added, to Section 384-I namely "Where switchboards are mentioned
380-17-FPN (NEW): Accept
CMP 9
SUBMITTER: Idaho Chapter IAEI
~ 6 5
Add a FPN to 380-17 to read: See 240-8,
~'~n.
SUBSTANTIATION: For the purpose of better correlation in the
field.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative;
Article 384: Reject
CMP 9
SUBMITTER: J.J. Kark, National Electrical Manufacturers Assn.
~ 6 6
ReviseArticle 384 to also specify LV switchgear
~nclosed
low-voltage power circuit breaker switchgear).
Revise Article Title: SWITCHBOARDS,PANELBOARDS,AND LV
SWITCHGEAR.
Revise 384-1:
171
low voltage switchgear is also included."
• EXPLANATIONOF VOTE:
BURNISTON: NEMAbelieves that the Panel's conclusion is
incorrect since LV switchgear is a specific product not already
covered by theproducts defined as switchboards or panelboards.
isolated from busbars by a metal barrier."
VOTE ON PANELRECO~ENDATION:
AFFIRMATIVE: g .
NEGATIVE: Hogan, Lelman, Wadhwa.
EXPLANATION OF VOTE:
HOr~N: Sameas Proposal No. 68.
LEIMAN: Sameas Proposal No. 68.
WADHWA: Sameas Proposal No. 68.
384-3(a): Reject
CMP 9
SUBMITTER: G. G. Biskupek, Federal Pacific Electric Co.
~ 6 7
To the last sentence, add the words, "in order to
prevent accidental contact with any conductor which remains
energized after the main devices in a service switchboard are
turned o f f . "
SUBSTANTIATION: Needfor clarification is demonstrated by Field
questions: isolate to prevent fault commutation, isolate to
prevent access, etc.?
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Code does not and cannot provide an
explanation or a reason for each requirement. I t would be
foolhardy to start now.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
384-3(c): Reject
CMP g
SUBMITTER: Robert W. Gilmore, Northwest Iowa Technical College
70 Add a second paragraph as follows:
provisions shall be provided for the installation of an
equipment grounding terminal bar approved for the purpose, and
i f used as service equipment, an equipment grounding terminal
bar approved for the purpose shall be provided and secured
inside of cabinet or panelboard for the attachment of all the
feeder and branch-circuit equipment grounding conductors, where
the panelboar~ is used with nonmetallic raceway or cable, or
where separate equipment grounding conductors are provided. The
terminal bar shall be bonded to the cabinet or panelboard frame
and shall not be connected to the neutral bar In other than
service equipment.
SUBSTANTIATION: Most electricians and inspectors do not realize
that when a panelboard approved for the purpose is used for
service equipment, is s t i l l a panelboard. Most inspectors and
electricians recognize the need for terminating the equipment
grounds on a separate bar when used in a panelboard on the load
slde of the service equipment, but don't see the need when a
panelboard is being used a service equipment.
NOTE: The intent of this Is not to require the manufacturer
to provide an equipment terminal bar with each panelboard but to
provide the provlsidns for one; some disconnect switches
approved for use as service equipment do not have these
provisions and cause a real problem for the electrician or
inspector. Whenthls equipment is used with an equipment
grounding conductor, there is no place to terminate properly,
forcing one ~o violate the NEC.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECO~MENDATION: UnanimouslyAffirmative.
384-3(a): Accept
CMP g
SUBMITTER: Charles J. Hart, National Electrical Contractors
PROPOSAL: 68 Deletethe second sentence of Section 384-3(a)
~IATION:
Compliancewith this requirement is next to
impossible. In multi-section switchboard installations, i t is
often unknown to the installer in what section a particular
overcurrent device is located.
Moreover, decisions to relocate circuit entrances Into the
switchboard section are often made in the field, particularly
when there are obstructions or conflicts with other equipment.
This requirementnecessitates.extenslve switchboard modification
in these instances.
Most switchboards have large open spaces without barriers
between adjacent sections. Fires can communicate between
sections even i f there are no conductors common to adjacent
sections. The interconnectlons between switchboards are often
made with insulated conductors capable of transmitting f i r e to
the adjacent section. This requirement does not add a
responsible degree of safety for these conditions.
PANEL RECOMMENDATION: Accept as Revised:
Revise .as in Proposal No. 69.
VOTE ON PANELRECOI~4ENDATION:
AFFIRMATIVE: g.
NEGATIVE: Hogan, Leiman, Wadhwa.
EXPLANATION OF VOTE:
HOGAN: Once again we have indicated on t'his proposal that we
are accepting what the proponent has desired. I t is my op~nlon
that we have f l a t l y rejected the proposal and then formed one of
o~r own. In any event I am voting negatively. Quite possibly,
i f we had utilized the word raceway or something similar to that
in lieu of the word barrier, I would have a different opinion
about the proposal we have formulated. I am completely, opposed
to the original proposal.
LEIMAN: The New York City code has had this requirement for
the last 12 years without causing any problems to any
installer. The Panel Recommendation wlll cause switchboards to
be loaded wlth metal barriers. This will lead to hazardous
conditions. Since the 1978 Code became effective, I have never
received any negative comments from the field or at any of the
IAEI meetings.
WADHWA: I agree'with the concept of the proposal, but the
substantiation offered is not correct. The shop drawings
generally are submitted by the manufacturers for approval of the
switchboard and approved by the Engineer' before the SWBDis
fabricated. The installer should be familiar with the location
and arrangement of protective devices.
•
384-3(a}(HOD 1978 NEC): Accept
CMP 9
SUBMITTER: NEMA
PROPOSAL: 69 Delete the second sentence of this Section.
~:I]I~"FAlg'rIATION: Cempliancewith this requirement is next to
impossible. In multi-section switchboard installations, i t is
often unknown to the installer in what section a particular
oyercurrent device is located.
Moreover, decisions to relocate circuit entrances into the
switchboard section are ~ften made in the field, particularly
when there are obstructions or conflicts with other equipment.
This requirement necessitates extensive switchboard modification
in these instances.
Most switchboards have large open spaces without barriers
between adjacent sections. Fires can c.emmunicate between
sections even i f there are no conductors commonto adjacent
sections. The interconnectlons between switchboards are often
made with insulated conductors capable of transmitting f i r e to
the adjacent section. This requirement does not add a
responsible degree of safety for these conditions.
PANEL RECOMMENDATION: Accept as Revised:
Add an exception as follows: 384-3(a). Exception:
"Conductors shall be permitted to travel horizontally through
Ivertlcal sections of swltchboards where such conductors are
384-3(f): Reject
CMP 9
SUBHITTER: A.G. Aschenbeck, Wayzata, MN
~ 7 1
Revise,as follows:
~ e
arrangement on three phase buses shall be A,B,C frem
f r o n t to back, top to bottom, or l e f t to right, as viewed from
the front of the switchboard or panelboard. The C phase shall
be that phase having the higher voltage to ground. Other busbar
arrangements shall be permitted for additions to existing
installations and shall be marked.
.
SUBSTANTIATION: There is too much confusion between the Hi-leg
being assigned to the "B" phase (center) as Is presently done
and the meter industry requirement of the Hi-leg on the right
side of their f a c i l i t i e s . The "Bu phase location serves no
purpose other than locating the Hi-leg in the center.
PANEL RECOMMENDATION: Reject.
PANEL COI4a4ENT: The Panel does not agree with the supporting
comment. No evidence to support the suggested change.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Cock.
EXPLANATION OF VOTE:
COCK: Section 384-3(f) should be clarified for 3-wlre delta
systems by adding the words: "on 3-phase, 4-wlre delta systems"
after the word "ground,~ in the second sentence. The second
sentence will then read: "The B phase shall be that phase
having the higher voltage to ground on 3-phase, 4-wire delta
systems. ~
This action will c l a r i f y the system"addressed in this
requirement. A 3-phase, 3-wire corner (B-phase) grounded system
cannot meet a requirement that B-phase be the highest voltage to
ground.
384-3(h)-(New): Accept
CMP 9
Secretary's Note: I t was the action of the Correlating
Committeethat t h i s Proposal be reported as a " r e j e c t , " because
less than two-thirds of the members e l i g i b l e to vote have not voted
in the affirmative.
SUBMITTER: Robert J. Freund, Chicago, IL
P]TOPO-ST
' TL-~. 72 Add new (h) as follows:
~ l l
busbars in equipment that operates at voltages over
250 volts between phases or between any phase and ground and
designed to carry currents of 1000 amperes or greater shall be
insulated. The insulation shall be solid, mechanically secure,
and suitable for the operating voltage.
SUBSTANTIATION: Busbars that are not insulated are a hazard to
personnel who install and maintain electrical equipment.
Busbars that are not insulated increase the likelihood of
power interruptions of vital electrical systems that affect the
public safety.
172
Ground fault protection only covers certain limited faults and
increases the possibility of interruptions.
Insulated busbars provide personnel safety and continuity of
service at a low cost.
PANEL RECOMMENDATION: Accept as Revised:
"All busbars in solidly grounded ws,e switchboards that operate
at voltages over 250 volts to ground but not exceeding 600 volts
phase to phase and rated 1000 an~oeres or greater shall be
insulated except at bolted Joints and connections. M
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 7.
NEGATIVE: Hogan, Burniston, Cock, Cramer, LaMorte.
COMMENTON VOTE:
BARKER: I have voted affirmative as the Panel Recemmendation
is better than nothing. In time i t will again require another
change to comply with the original proposal. Insulated busbars
would greatly reduce the magnitude and resulting hazards of
burndowns from arcing faults when failures occur.
LEIMAN: I haven't voted negatively on this proposal but would
like to be on record to discuss this at our next meeting in
Dece~foer. I t will give us more of an input when I attend our
IAEI Sectional meetings.
EXPLANATION OF VOTE:
HOGAN: I have voted negatively on this proposal for two
reasons: (I) to call as much attentlon,to the proposal as is
possible and (2) to give the Panel another opportunity to
discuss the Proposal. I am not satisfied that we have actually
accomplished what we intended~
BURNISTON: This proposal imposes a design requirement on
equipment presently covered by A~erican National Standards and
Underwriters Laboratories Inc. standards which deliberately do
not include this requirement.
This type of equipment is not intended to be installed or
maintained while energized.
Incomplete insulation as specified in this proposal will lead
to a false sense of security on the part of personnel and will
encourage the unsafe practice of working on energized equipment.
Addition of insulation to busbars in this equipment will lead
to voltage stress concentrations on the insulation and result in
failure of the insulation which maY cause equipment failure
instead of preventing i t .
These products as presently built, have not experienced
history of power interruptions and personnel safety hazard
sufficient to j u s t i f y this requirement.
COCK: I f busbars are to be insulated within this voltage
range there should be an exception in Section 230-95 which would
not require ground fault protection of equipment for insulated
busbars.
The Panel has recognized that bolted joints and connections
cannot be insulated. I submit that the condition of "insulated
busbars" and "uninsulated Joints and connections" tends to give
the workman a false sense of security since he tends to assume
he is working on an "insulated system."
CRAMER: I disagree with the supporting comment that busbars
that are not insulated are a hazard to personnel who install and
maintain electrical equipment. Goodsafety practices can
accomplish much more than any form of insulation.
Bare busbars are allowable even when located outside of
enclosures provided they are suitably guarded. (See Section
110-17(a).) Here in a switchboard which already meets
requirements of Section 110-17(a), we're requiring additional
guarding in the form of insulation. This is not necessary.
Furthermore, there's no real substantiating data to indicate
that this will significantly add to safety. The only certain
thing i t will do is increase costs.
LA MORTE: Submltter alleges that unlnsulated busbars are a
hazard to personnel who instal] and maintaln.electrical
equipment. I f personnel safety is the issue, this requirement
would accomplish nothing, in that busbar Joints and cable
connections would s t i l l be exposed; and these are the areas
where problems and failures requiring attention occur. Also
good safety practice dictates that you do not rely on electrical
insulation; consequently, when working on electrical equipment,
treat i t as i f bare. Such reliance can lead to carelessness and
a false sense of security.
I t is a widely known fact that covering a bus with a thin
coating does not make i t safe to touch. See NFPANo. 70-B, page
48 - "Electrical Equipment Maintenance," quoted following:
"Although the bus and connections are insulated in metal clad
switchgear, THE INSULATION IS NOT DESIGNEDTO PROTECTAGAINST
ELECIRICAL SHOCK. CONTACTWITH THIS BUS OR ITS CONNECTIONS
SHOULD BE AVOIDEDWHENTHE SWITCHGEAR IS ENERGIZED." (The
capit'als are as in the NFPA No. 70-B text.)
Submitter alleges that busbars that are not insulated increase
the likelihood of power interruptions of vital electrical
systems that affect the public safety. No evidence has been
submitted to substantiate this claim - merely hearsay. In fact,
i f low-voltage buses were required to be insulated,
manufacturers would begin to reduce or eliminate phase:to-phase
and phase-to-ground air clearances and depend solely on
insulation barriers. I t is expected that bus failures due to
insulation breakdown would increase, resulting in more power
interruptions.
Submitter a11eges that implementation of this proposal can be
accomplished at low cost. This statement is not backed up with
any cost analysis; consequently, i t is unfounded. I t is
expected that the cost of switchgear and power distribution
equipment would increase dramatically.
Existing switchgear
designs, in general, would not be modifiable to incorporate bus
insulation; consequently, major redesign programs would need to
be initiated by the various equipment manufacturers. All NEMA,
ANSI and UL standards would need to be revised. I t is estimated
that a five to ten year timetable would be involved. Atte~)tlng
to incorporate insulated bus systems on existing designs will
involve design modifications and de-rat(ng factors and result in
equipment designs which would not be in compliance with NEMA,
ANSI and UL standards.
In conclusion, experience in the f i e l d does not warrant or
Justify the need for insulated busbars in metal-enclosed,
low-voltage electrical equipment. In fact, this requirement
would not only increase costs substantially but would reduce
r e l i a b i l i t y and complicate maintenance. I t is expected that
f i r e and smoke damage would increase as a result of, Insulatlon
burning associated with bus faults. Ionized gases resulting
from insulation burning would tend to propagate the fault arc,
causing major equipment damage and power interrup~lons.
Plant safety records and maintenance experience do n o t
indicate that unlnsulated buses in enclosed equipment are a
hazard to maintenance personnel. One of the problems with
insulated buses, for example, in high-voltnge equipment is that
i t becomesd i f f i c u l t to tie grounds to these buses for safety
during maintenance. This would also apply to low-voltage
equipment that was completely insulated.
384-3(h)-(New): Reject
CMP g
SUBMITTER: Donald C. Smith, Texas Chapter IAEI
~ 7 3
Add (h) as follows:
.---T~T)--A-ny multi-section service switchboard incorporating
multiple main overcurrent devices feeding subsections within the
same switchboard shall indicate by use of permanent mimic bus on
the face of the switchboard the bussing schematic of that
switchboard.
SUBSTANTIATION: For many years design engineers have recognized
the need for mimic bus on the front of switchboards for the
safety of personnel and ease of identification. In modern
design of switchboards installed on large industrial type
installations, mimic bus is being utilized more and more. Some
of the reasons for using the mimic bus are: When viewing the
bus assembly from the rear o f the switchboard, line and load
busses often are not easily distinguishable.
Also, often time
the rear of the switchboard is not accessible thereby making i t
hard to determine which main device feeds which group of
sub-devicos. Someswitchboards with insulated buses make i t
hard to identify line and load connections. Lack of
identification presents an obvious hazard to workmen.
PANEL RECOMMENDATION: Reject;
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Leiman.
EXPLANATION OF VOTE:
LEIMAN: I agree with the supporting comment.
384-6-(New): Accept
CMP 9
Secretary's Note: I t was the action of the Correlating
Committee that the Panel shall delete reference to new and
existing installations. The application of installation rules
is the function of the authority enforcing the Code.
SUBMITTER: Samuel S. Levinrad, VA, Wash., DC
PITOITO-SA
' I_-•~. 74 Renumberexisting Sections and add new 384-6 as
384-6. Water Pipes and Accessories. Any pipe or duct system,
foreign to the electrical installation, shall not be located in
the vicinity of switchboards and service equipment, nor enter or
pass through rooms specifically designed to house this type of
equipment. No piping or air conditioning duct system, other
than those systems which serve the electrica~ equipment space,
shall be located in the vicinity of any switchgear or service
equipment nor shall they pass through rooms or architectural
space specifically provided for the housing of such equipment.
SUBSTANTIATION: Sections 450-47 and 710-9 are the only areas
within NEC prohibiting foreign piping (water pipes) in areas
containing electrical equipment. With the advent of the large
office and apartment house complexes, i t has becomemore
economical to purchase primary voltage power, feed through the
switchgear, stepdown to utilization voltage and distribute
throughout the complex. We have seen hospitals and building
complexes wherein chilled water pipes, steam pipes, cold water
pipes, sanitary cleanouts and other piping pass directly over
the building's secondary or primary switchgear. In addition,
some a~chitects s t i l l utilize the electrical closets as a chase
for other than electrical conduit. The addition of a paragraph
such as recommended will aid the inspection authority having
Jurisdiction in performing its function and assure a safer
installation.
PANEL RECOMMENDATION: Accept as Revised:
Change 384-1 to "General." Change the "Scope" to paragraph
(a) and "384-2. Other Articles" to paragraph (b). Number the
following 384-2:
384-2 Installation.
(a) New Buildings. In every new building hereinafter
173
delete the word "fireproof" and replace with the words
"flre-resistant."
SUBSTANTIATION: In its present form, because of the word
"fireproof" for which there appears to be no standard or
definition, the section has l i t t l e value either to the building
designer or to the constructor.
I f in fact, the intent is to establish a specific level of
f i r e resistant integrity, then the proposal could be expanded to
include 1 hour, 2 hour, 3 hour,
etc., based on, as example, ASTM-E119, etc.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: We do not intend to establish fire-reslstant
ratings for ceiHngs above switchboards.
VOTE ON PANELRECO~MENDATION: UnanimouslyAffirmative.
designed, constructed or erected, an electrical service,
distribution, transformation or control equipment shall be
located in rooms or spaces dedicated exclusively to such
equipment. No foreign piping, ducts or other mechanical or
architectural equipment or appurtenances shall be permitted to
be installed in, enter or pass through such spaces or rooms.
(b) Existing Buildings. Previously approved electrical
installations shall be permitted to remain.
(c) Existing Buildings Being Remodeled. An existing building
which is being remodeled more than 50 percent or in which a new
electrl~al service and distribution system is being installed
shall conform to the provisions of paragraph (a) of this section.
Exception No. 1: Control equipment which by its very nature
or because of other rules of this Code must be adjacent to or
within sight off its operating machinery.
Exception No. 2: Ventilating, heating or cooling equipment
that serves the electrical rooms or spaces.
Exception No. 3: Transformers,,controllers, switches and
distribution equipment located throughout industrial plants
which are isolated from foreign equipment by height or physical
enclosures which will afford adequate mechanical protection from
vehicular t r a f f i c , accidental contact by unauthorized personnel
or accidental spillage or leakage from piping systems.
Exception No. 4: Outdoor electrical equipment located in
weatherproof enclosures protected from accidental contact by
unauthorized personnel or vehicular t r a f f i c or accidental
spillage or leakage from piping systems.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE:. 9.
NEGATIVE: Biermann, Cremer, LaMorte.
COMMENTON VOTE:
ECKARDT: While the concept can be supported terms such as
"Every new building" and "Existing buildings" would seem to
include residences. I do not believe t h i s is the Panel's intent.
COCK: An "Exception No. 5" should be added for one and two
family dwellings.
DEMING: I am in agreement with'the proposal) but believe we
have exceeded our authority in Section 384-2(b) making the rule
that previously approved electrical installations shall be
permitted to remain. The Judgement of whether or not previously
approved electrical installations are currently safe should be
l e f t to the inspection authority having Jurisdiction.
In Section 384-2(c) we should insert the word "structurally"
before the word remodeled, which appears In the t i t l e and f i r s t
sentence. The word "structurally" clarifies our intent with
regard to the type of remodeling.
EXPLANATION OF VOTE:
BIERMANN: The precept of a double standard of rules for
existing buildings and new buildings is a bad code. Moreover,
retroactive rules are worse. The declaration that previously
approved electrical installations shall be permitted toremain
would clearly disfranchise the application of the code rules no
matter how hazardous the condition.
CRAMER: Whenthis ~unen&nent to this proposal was originally
considered, i t appeared desirable. Later reflection on i t has
uncovered some deficiencies.
(I) Interpretation of what constitutes a space can vary from
person to person. Someindustry users place switchgear or motor
control centers in one portion of a machinery room. Somemight
consider this a violation because of machinery and piping in the
same room with electrical; others might not consider this a
vlolatlon because of the electrical gear in its own space.
Similarly in a home, the mount of space required for a service
entrance panelboard is vague.
(2) Industrial control rooms with operator attended control
panels would f a l l under this section. Desks, f i l e cabinets,
drinking fountains and other accessory items are included In
these roo~s and would be In violation of the proposal.
(3) The exceptions themselves appear incorrectly located
afterafterparagraphParagraph l~I~ They appear to be more logically located
384-9 (HOD1978 NEC): Accept
CMP 9
SUBMITTER: C~ g
ili~-O'FO-~-~.76 Revise Section 384-9 so as to read as follows:
~onductor
Covering. All insulated conductors used inside
of switchboards shall be flame retardant and shall be rated not
less than 600 volts.
SUBSTANTIATION: The panel feels that i t is unnecessary to
continue to add every new wire type that is brought on the
market. The simple sentence above is all that is necessary to
assure,that the proper wire will be used in switchboards.
PANEL RECOMMENDATION: Accept as Revised:
Change 384-9 to read: "Conductor Insulation. An insulated
conductor used within a switchboard shall be listed, flame
retardant and shall be rated not less than the voltage applied
to i t and not less than the voltage applied to other conductors
or busbars with which i t may come in contact.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative. ,
384-9: Accept
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
I~TOl~)~)~.• 77 See the Technical Subcommittee "Recommendations"
un--n-d'e'~--t-Fe definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC °findings" under the definition of
"Approved for the Purpose" In Article 100.
PANEL RECOI~ENDATION: Accept as Revised:
As Proposal No. 76.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
384-15: Reject
C~ 9
SUBMITTER: Mike Brendle, Mt. Vernon, WA
78 Add the following paragraph after the present
text:
"Not more than 90 percent of the total spaces in any lighting
and appliance branch-circuit panelboard in a one-family chwelling
shall be occupied after i n i t i a l installation."
SUBSTANTIATION: The building and electrical construction
industry, being very competitive, often causes electrical
installation to meet only the minimum NEC requlren~nts. The
owner of a new one-family dwelling often encounters a panelboard
that has no available space for overcurrent devices. The only
course of action for the electrician is to install tandem
circuit breakers. These are approved for this application, but
they increase current density and heating within the
panelboard. I t is the intent of this amendment to provide a
one-family dwelling with an electrical service which will
accomodate the diverse electrical needs of the future.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANELRECOI&M[NDATION: UnanimouslyAffirmative.
LaMDRTE: At a glance i t appeared that this proposal, with
some modifications, would be a good one. The revised proposal
taking i t part by part was a disappointment, and I have voted
negative for the following reasons:
I . There seems to be a lack of definition to "Spaces or
Rooms." Is space, working space as defined in Article 1107 Are
rooms totally enclosed or merely a screened area?
2. Section 450-47 on Transformers does not consider piping
for f i r e protection foreign to the electrical installation.
Would the proposed Section 384-2 permit sprinkler piping for a
unit substation line-up consisting of primary switches,
transformer and low voltage section?
3. In Part (c) who could determine i f a building is being
remodeled more than 50 percent? I f a building Is required to be
remodeled greater than 50 percent, one way of getting around the
NEC would be to complete the installation In several different
384-16(a): Reject
CMP 9
SUBMITTER: Ralelgh W. Rheuby, Jr., Hueytown, AL
~ 7 9
Add the words "one and" after the words "on the
su~-'u'~'Ty-side by."
Revise Exception No. 2 as follows:
Exception No. 2: Individual protection for lighting and
appliance branch-circuit panel boards Is not required where such
panelboards are used as service equipment in supplying service
t o signs, pumps and equipment separate from buildings of
occupancy.
SUBSTANTIATION: Since the words from the 1975 NEC Section
384-16(a), Exception No. 2 - and .where any bus supplying 15- or
20-an~)eres circuits is protected on the supply side by an
overcurrent service, have been deleted from the 1978 NEC Section
384-16(a), Exception No. 2. The Code does not require a main
disconnect or overcurrent service for service equipment of
residential housing. This constitutes a conflict and confusion
between Section 384-16(a), Exception No. 2 and Section 230-79(a)
through (d) besides the need for the protection of equipment and
safety of persons.
This proposal and any improvements are for con~ideratloo to
phases.
4. The objection I have about the 4 exceptions is that i t
expands beyond the scope of the Article which should be on
Switchboards and Panelboards.
384-7: Reject
CMP g
SUBMITTER:" H. K. Glenn, Pacific Coast Electrlcal Assn.
75 In 384-7, delete the word "nonfireproof" and
~with
the words "nonfire-reslstant." In Exception No. 1,
174
'
Typical Transformer
Ratings (kVA)
15
30
45
cause the Code to require a main disconnect current protection
for residential occupancy panel and to be in accord with Section
230-79(a) through (d).
PANEL RECO~MENDATION: Reject.
PANEL COMMENT: See Panel•actlon on Proposal No. 80.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
I sec.
83.4
125.0
Panelboard M a i n
PanelboardMain
Bus (amps)
Circuit Breaker (amps)
IUU
i00
225
384-16(a), Exception No. 2: Accept
CMP 9
SUBMII-TER: Idaho Chapter IAEI
IM~roI~FO-S-'A~-T.8
' 0 Delete 384-16(a), Exception No. 2.
3u~I~NItATION: This is a subject that has come up in every
Code for a number of years and has been rejected or blocked
every time. I t is not quite clear as to the reason why except
that the supporting comment of the "con" nature seems to
reiterate the thought that no one has been electrocuted,
injured, or there are not any f i r e records showing contributory
factors to this exception. I t seems that some pressures are
applied in areas beyond the Code Making Panels' jurisdiction
because Proposal No. 83 in the Preprint for the 1978 Code was
submitted ~d accepted by Code Making Panel 9.
This seems to be indicating that politics has a greater
bearing on Code making than the desire for having compatible
Code especially when the negative pressures come from the
segments of the industry not regulated by the NEC requirements.
In other words, why is a residential service permitted to have
equipment that is not only less restrictive than the other
occupancies but can be mere easily tampered with by
inexperienced persons Just because they feel they can do as they
please w!th what they own even though i t may endanger their next
door neighbor.
Proposal No. 83 page 204 of the 1978 NEC Preprint is evidence
that i t is prime time that this exception be retired from the
NEC.
PANEL RECOMMENDATION: Accept as Revised:
I Add to Exception No. 2 at beginning of sentence: "For existing
installations,."
VOTE ON PANELRECOMMENDATION:,
AFFIRMATIVE: 11.
NEGATIVE: Biermann.
EXPLANATION OF VOTE:
BIERMANN: I am in favor of ~he proposal. I am not in favor
of establishing one standard for existing dwellings and another
for new dwellings.
~
IUU
i00
225
.
The overcurrent protection of a 15 kVA unit substation with a
f u l l load current of 41.7 amperes, 15 ampere branch-circuit
breaker, and 100 amp standard panelboard bus, is not enhanced
with the standard 100 amp transformer secondary main breaker
rated at over twice f u l l load (calibrated to t r i p in 6 minutes
at 200 amperes--UL489).
A branch-circuit fault close to the panelboard is seen by the
instantaneous elements in both the main and the corresponding
branch-circuit breaker. This can drop all the substation load
possibly creating an unsafe condition due to a con~lete loss of
power to c r i t i c a l process instruments or to the area lighting
being served.
The identification and marking of each branch circuit is
already a requirement of NEC 110;22 and assists in monitoring
the load connected to each phase.
I believe that the restrictions of this proposal exceed those
allowed under 384-16(a) Exception No. 2 for a safe installation.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirement is necessary.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
384-17-(New): Accept
CMP 9
Secretary's Note: I t was the action of the Correlating
Committee that the Panel shall delete reference to new and
existing installations. The application of installation rules
is the function of the authority enforcing the Code.
SUBMITTER: Samuel S. Levinrad, VA, Wash., DC
]~TO]~TSA
' -L-~." 83 Renumberexisting Sections and add new 384-17 as
384-17. Water pipes and accessories. No piping or duct
system foreign to the electrical installation, shall be located
in the v i c i n i t y of panelboards and service equipment, or pass
through rooms specifically designed to house this type of
equipment. No piping or air conditioning duct system, other
than those systems which serve the electrical equipment space,
shall be located in the v i c i n i t y of any switchgear, panelboards
or service equipment and shall not pass through rooms or
architectural space specifically provided for the housing of
such equipment.
SUBSTANTIATION: Sections 450-47 and 710*g are the only areas
within the NEC prohibiting foreign piping (water pipes) in areas
containing electrical equipment. With the advent of the large
office and apartment house complexes, i t has become mere
economical to purchase primary voltage power, feed through the
switchgear, stepdowo to u t i l i z a t i o n voltage and distribute
throughout the complex. We have seen hospitals, office
buildings and apartment houses wherein chilled water pipes,
steam pipes, cold water pipes, sanitary cleanouts, pass directly
over the building's secondary or primary switchgear. In
addition, some architects s t i l l u t i l i z e the electrical closets
as a chase for other than electrical conduit. The addition of a
paragraph such as recommended will aid the inspection authority
having jurisdiction in •performing its function and assure a
safer installation.
PANEL RECOMMENDATION: Accept as Revised.
I ~ee Panel action on Proposal No. 74.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Biermann, LaMorte.
COMMENTON VOTE:
ECKARDT: See my comment under Proposal No. 74.
COCK: An "Exception No. 5" should be added for one and two
family dwellings.
EXPLANATION OF VOTE:
BIERMANNi See my comments on Proposal No. 74.
LaMORTE: See comments on Proposal No. 74.
384-16(c): Reject
CMP g
SUBMITTER: O. E. Dillon, Border County Div. IAEI
~ 8 1
Revise as follows:
~ h e
total load of appliances or equipment fastened in
place and connected t o any overcurrent device located in a
panelboard shall not exceed 80 percent of the overcurrent device
rating where in normal operation and load will continue for
three hours or mere.
"SUBSTANTIATION: This section is practicably unenforceable
unless the jurisdiction has the man power to make periodic
checks of all occupancies (commercial and residential) to
determine i f the portable appliances are overloading any
overcurrent devices. See the attached opinion* of the San Diego
City Attorney.
*See Border County Div. IAEI substantiation for proposal for
' llO-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirement is necessary.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
384-16(d), Exception No.' 2-(New): Reject
CMP 9
SUBMI1-FER: D. H. Mclntosh, E. I. du Pont de Nemours & Co.
I~TOlbI~S';~-T.'82
Add exceptionas follows:
~ i o n
No. 2: Individual protection for lighting and
appliance branch-circuit panelboards is not required in
.
industrial establishments where conditions of maintenance and
supervision indicate that only qualified persons will service
the installation; the transformer primary (supply) is protected
by overcurrent protection in accordance with Section •
450-3(b)(1); and, the conductors tapped to the transf6rmer
secondary meet all of the following conditions:
(1) the length '
of the tap conductors does not exceed 10 feet; (2) the ampacity
of the tap conductors is not less than the ampacity of the
panelboard; (3) the tap conductors are enclosed in a raceway
approved for the purpose.
SUBSTANTIATION: The following table of unitized
transformer-panelboards illustrates the application of 3 typical
sizes of 480-208/120-volt transformers supplying lighting and
appliance branch-circuit panelboards. A transformer secondary
main circuit breaker requires an unjustified increased cost f o r
the electrical installation without a commensurate increase in
safety.
384-18: Accept
'
CMP 9
SUBMITTER: TSC-Approvedfor the Purpose
84
See the Technical Subcommittee "Recommendations"
un--6-de~--t'~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I ~hange the word "approved" to "designed."
VOTE ON PANEL RECOMMENDATION:
"'AFFIRMATIVE: 9.
NEGATIVE: Hogan, Barker, Cramer.
175
t
EXPLANATION OF VOTE:
HOGAN: I don't find the word "designed" any more palatable
than the word "identified" in this section of the Code. I would
much prefer the word, " l i s t e d . " At least we have a definition
in the code book for i t . The word "designed" really doesn't tie
t h i s down to anything.
BARKER: The use of the word "designed" would result in
confusion and lack of uniformity. These enclosures should be
listed.
CRAMER: See comments on Proposal No. 74.
384-21: Reject
CMP 9
SUBMITTER: J.A. Fehr, General Electric Co
lsITOlsO-SA
' l--~•. 85 Revise as follows:
~Busbars.
B~sbars may be copper or aluminum. I f r i g i d l y
mounted, they may be bare.
SUBSTANTIATION: Section 110-5 states "Conductors normally used
to carry current shall be of copper unless otherwise provided in
this Code."
Since no such provision is contained in Article 384, this
could be interpreted to mean all conductors in switchboards and
panelboards must be copper. For manyyears the industry has
manufactured these products with aluminum conductors and in
large volume. The proposed change will bring this Arbicle into
accordance with the intent of the proposed change to Section
110~5 in the 1978.NEC (Proposal No. 76).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Such practice is not prohibited by present Code.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Cramer, Doming.
EXPLANATION OF VOTE:
CRAMER: I believe the submitter is correct. To avoid
misunderstanding we should add statement, "Busbars may be copper
or aluminum" as a fine print note.
DEMING: I agree with the submitter. All he is asking for is
additional c l a r i t y .
384-21: Accept
~
CMP 9
SUBMITTER: CMP 9
~ 8 5 A
Revise384-21 to read: "Busbars shall be
~mounted."
SUBSTANTIATION: See Proposal No., 72.
FANEL RECOMMENDATION: Accept as Revised:
"Insulated or bare busbars shall be r i g i d l y mounted."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
Table 384-26: Accept
CMP 9
SUBMITTER: TSC-Nominal Voltage
l~TOIsl~S'Al--~.'86
The voltage designation' in Column i should be
~ t o
read:
Not over 127 volts;
Not over 254 volts;
Not over 635 volts;
SUBSTANTIATION: To conform to the method to express maximum
voltage as per guidelines developed by the TSC on nominal
voltage.
PANEL RECOMMENDATION:' Accept as Revised:
Add the word "nominal" after "125 volts, .... 250 volts," and
"600 volts" in Table 384-26.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
384-27: Reject
CMP 9
SUBMITTER: Robert W. Gilmore, Northwest Iowa Technical College
~ 8 7
Revise as follows:
~oard
cabinets or panelboard when used as service
equipment shall be grounded in'the manner specified in Article
250 or Section 384-3(c). An equipment grounding terminal bar
approved for the purpose shall be provided and secured inside of
cabinet or panelboard for the attachment of all the feeder and
branch-circuit equipment grounding conductors, where the
panelboard is used with nonmetallic raceway or cable, or where
separate equipment grounding conductors are provided. The
terminal bar shall be bonded to the cabinet or panelboard frame
and shall not be connected to the neutral bar in other than
service equipment.
SUBSTANTIATION: Most electricians and inspectors do not realize
that when a panelboard' approved for the purpose is used for
service equipment I t is s t i l l a panelboard. Most inspectors and
electricians recognize the need for terminating the equipment
grounds .on a separate bar when used in a panelboard on the load
side of the service equipment, but don't see the need when a
panelboard is being used as service equipment.
Adding the words "when' used as service equipment" should help
to enforce the meaning of the article.
Also, there is a need for the change from "approved" to
"approved for the purpose" otherwise an inspector can approve
any type of f i t t i n g for-equipment ground termination other than
the equipment grounding terminal bar provided by the
manufacturer.
NOTE: The intent of this is not to require the manufacturer to
provide an equipment terminal bar with each panelboard but to
provide the provisions for one; some disconnect switches
approved for use as service equipment do not have these
provisions and cause a real .problem for the electrician or
inspector. When using equipment without these provisions and an
equipment grounding conductor or conductors are present there is
no place to terminate them properly, forcing one to violate the
NEC.
PANEL RECOMMENDATION: Reject.
HANbL COMMENT: We do not agree with the supporting comment and
do not believe that the Proposal accomplishes what the submitter
intended.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
i
384-27, Exception No. 2-(New): 'Accept
CMP 9
SUBMITTER: RobertB. West, St. Louis, MO
P]TOIsO-S'A'L-~88
Add a new exception as follows:
~ i o n
No. 2: The terminal bar for equipment grounding
conductors shall be permitted to be connected to the neutral.bar
at separate buildings in accordance with the provisions of
Section 250-24, Exception No. 2.
SUBSTANTIATION: This is to correct a conflict. Where the
grounded circuit conductor is grounded at a separate building in
accordance with Section 250-24, the terminal bar for equipment
grounding conductors must be bonded to the neutral bar in order
to complete the ground-Sault current path to the service.
• The reference to Section 250-24, Exception No. 2 correlates
with my proposal to amend Section 250-24. I f Section 250-24 is
not amended, the reference in this proposal should be Section
250-24(a).
PANEL RECOMMENDATION: Accept as'Revised:
I Delete the words "Exception No. 2" at the end of sentence.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 11.
NEGATIVE: Barker.
EXPLANATION OF VOTE:
BARKER: In accord with Articles 230 and 250, when the
conductors enter the second building they are service conductors
to that building except for the exceptions. To add this to this
section would be confusing and could result in improperly
grounded installation with resultant hazards. We should leave
services and grounding to the appropriate Panel, with only a
cross-reference in this Section.
384-XX-(New): Accept
CMP 9
Secretary's Note: I t was the action of the Correlating
Committee that the Panel shall delete reference to new and
existing installations. The application of installation rules
is the function of the authority enforcing the Code.
SUBMITTER: Southwestern Section IAEI
~ 8 9
Add section as follows:
3ITATX]~Z-. Electrical switchboards, electrical controls or control
panels other than those related to the Mechanical Code shall not
be located in any machinery room.
SUBSTANTIATION: The following problems have arisen due to the
electrical requirements included in other uniform codes. Too
often this requirement can be overlooked from the standpoint of
design and plan check, therefore, creating a situation that can
result in enormous cost in order to satisfy all model code
requirements after the installation has been made. I feel that
the electrical requirements included in other codes should be
cross-referenced back to this Code.
The 1976 edition of the Uniform Mechanical Code will allow the
following equipment in a machinery room:
(1) Lights and receptacles
(2) Machinery room exhaust fans and blowers
(3) Any refrigerating condensing unit or portion
thereof
(4) Circulating pumps for condensers, cooling
towers, or cooling coils
(5) Air compressors serving only automatic controls
within the refrigerating or cooling system
(6) Electrically operated valves for the control of
a refrigerant or for the control of the
circulation of a cooling fluid
(7) Blowers and fans for cooling towers or for
condensers
, (8) Any electric control or control panel for any of
the above items.
A readily accessible single emergency refrigeration control
switch shall be provided to shut off all electrically operated
machinery in any machinery room, except the exhaust ventilation
system complying with UMC Section 1508. Such switch shall be
controlled from a point outside of, and within ten feet of the
required opening to the machinery room i t serves, and the switch
shall be )abeled to comply with UMC Section 1519. Except as
modified by this article, wiring and equipment shall comply with
the applicable requirements of Chapter I through 4.
PANEL RECOMMENDATION: Accept as Revised:
I See Panel actlon on Proposal No. 74.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 9.
NEGATIVE: Biermann, Cramer, LaMorte.
176
COMMENTON VOTE:
~UCK: An "Exception No. 5" should be added for one and two
family dwellings.
EXPLANATION OF VOTE:
BIERMANN: See my comments on Proposal No. 74.
CRAMER: See comments on Proposal No. 74'.
LaMORTE: See comment for Proposal No. 74.
384-XX-(New): Accept
CMP 9
Secretary's Note: I t was the action of the Correlating
Committee that the Panel shall delete reference to new and
existing installations. The application of installation rules
is the function of the authority enforcing the Code.
SUBMITTER: GeorgeAlexander, Fresno, CA
~ 9 0
Electrical switchboards, electrical controls or
controTpanels other than those related to the Mechanical Code
shall not be located in any machinery room.
SUBSTANTIATION: The.following. problems have arisen due to the
electrical requirements included in other uniform codes. Too
often this requirement can be overlooked from the standpoint of
design and plan check, therefore, creating a situation that can
result in' enormous cost in order to satisfy all model code
'requirements after the installation has been made. I feel that
the electrical requirements included in other codes should be
cross-referenced back to this Code.
The 1976 edition of the Uniform Mechanical Code will allow the
following equipment in a machinery room:
I ) Lights and receptacles
2) Machinery room exhaust fans and blowers
3) Any refrigerating condensing.unit or'portion
thereof
4) Circulating pumps for condensers, cooling towers,
or cooling coils
5) Air compressors serving only automatic controls
within the refrigerating or cooling system.
6) Electrically operated valves for the control of a
refrigerant or for the control of the circulation
of a cooling fluid
7) Blowers and fans for cooling towers or for
condensers
8) Any electric control or control panel for any of
the above items
A readily accessible single L;mergency refrigeration control
switch shall be provided to shut off all electrically operated
machinery in any machinery room, except the exhaust ventilation
system complying with UMC Section 1508. Such switch shall be
controlled from a point outside of, and within ten .feet of, the
required opening to the machinery room i t serves, and the switch
shall be labeled to 'comply with UMC Section 1519.- Except as
modified by this article, wiring and equipment shall comply with
the applicable requirements of Chapter I through 4.
PANEL RECOMMENDATION: ACcept as Revised:
i See Panel action on Proposal No. 74.
"VOTE ON PANELRECOMMENDATION:
PJ-PIRMAIIVE: 9.
NEGATIVE: Biermann, Cramer, LaMorte.
COMMENTON VOTE:
COCK: An "Exception No. 5" should be added for one and two
family dwellings.
EXPLANATION OF.VOTE:
:
ee my comments on Proposal No. 74.
CRAMER: See comments on Proposal No. 74.
LaMORTE: See comment for Proposal No. 74."
177
Table 400-4: Accept
CMP 6
SUBMITTER: William H. Korcz, Shell Development Co./Shell
C'li;~-~-F~3T-Co.
I PROPOSAL: 65 Add the following new designation type letters to
l'~Bl-~-~I;{IO-4 in the appropriate service cord (SP, SV, SJ, S; SDR)
sections as shown in table and include a new Note 10 as follows:
SUBSTANTIATION: The current NEC designation syste~ for service
type flexlble cords (Article 400) does not provide for a broad
group of acceptable cord insulations and outer coverings based
upon thermoplastic rubber materials. What we propose is a
revision to Table 400-4 as shown in the "Recommended Text"
section which will provide the necessary differentiation of this
group from currentqy designated "rubber" and "thermoplastic"
insulation and outer covering classes of materials.
The substantiation for thls proposal has two aspects:
(I) performance and fabrication considerations, and
(2) the expressed need by cable producers and
users to develop this new type designation for thermoplastic
rubber materials.
Detailing of arguments arising from these viewpoints is found
in the accompanying appendices* to this proposalS:
Appendix 1: Sgmmary
Appendix 2: Introduction, general background,
acceptance and performance, history,
terminology and definitions associated
with thermoplastic rubbers
Appendix 3: Performanceconsiderations based upon
UL fact finding programs and UL No. 62
listings
Appendix 4: New type designation survey of cable
manufacturers and users.
*Appendices have been supplied to CMP members.
PANEL RECOMMENDATION: Accept as Revised:
I Delete hyphens (1 places) in type letters preceeding "E" in
proposed additions to Table. Delete proposed Note 10 and all
references to Note lO.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
be permitted to be used at the ampacities shown in the tables of
this article with any of the equipment or devices specified in
Articles 210, 220, 230, 240, 250, 380, 384, 410, 430, 440, 517.
This section shall becomeeffective January 1( 1985.
SUBSTANTIATION: Problem: Terminal restrictions imposed upon
conductors do not recognize improved insulation technology.
These restrictions cause under-utillzatlon of conductors and
raceway systems. This under-utillzation causes excess costs for
both material and labor, wasting both natural resources and
energy.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AI-~IRMAIIVt: 6.
NEGATIVE: Coffey, Conley, Durham, Hogan, Jannot.
EXPLANATION OF VOTE:
COFFEY: T oppose the panel rec~mendation to accept this
proposal because the ampacity and operating temperature are
adequately covered in Sections 310-15 and 310-9 respectively of
the 1978 NEC. This proposal does nothing to alleviate the
problom described in the substantiation for the proposal,
namely, that restrictions on the terminal presently control the
load current through the insulated wire. The intent of the
proposal is good but I t should appear in'the appropriate
sections of the Code, that cover the use of wire and cable
terminations.
\
CONLEY: The Panel Comment on Proposal No. 54 is that
terminations do not determine conductor ampacitles. Neither
should conductor ampacities dictate the ratings of terminals on
connected equipment. I t is desirable that all readily available
conductors, equipment and devices be thermally compatible - that
appears to be the intent of the proposal. See also my Co~ent
on Proposal No. I.
DURHAM: This proposal is in conflict with 410-11 and 110-11
in that i t would permit conductors to be used in equipment with
higher temperatures than that for which the conductor is rated.
HOGAN: I find it, impossible to understand how CMP 6 can make
the statement made in your Panel Co¢mnent on Proposal No. 54 and
then to accept the substantiating comments made by the proposer
of the proposal. The Correlating Committee had better decide i f
CMP 6 has the responsibility of telling how and where the
conductors for which they are responsible may be used regardless
of the provisions of all the other sections mentioned in this
proposal. We may find that there are some panels that might not
like to be told that information.
JANNOT: The panel should assign a section number.
ARTICLE 400 -- FLEXIBLE CORDSAND CABLES
Table 400-4: Reject
CMP 6
SUBMITTER: R. Droste, National Elevator Industry, Inc.
IqII~OS'AL-~63 Changethe range of wire sizes for Hard Service
~ m
18-2 to 20-2 AWG.
SUBSTANTIATION: More extensive use of electronics with
corresponding lower required currents permits use of smaller
wire.
Such a change was already made in 1978 Code on elevator
cables, pages 236 and 237.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Table 400-4: Accept
CMP 6
SUBMITTER: Peter Pol)ak, The Aluminum Association
~ 6 6
Insert "copper" in the second tabular heading
under "Size AWG."
SUBSTANTIATION This proposal is submitted to c l a r i f y the proper
conductor tot the application. Makes clearer the fact that the
conductor is to be copper. The panel is referred to the
proposed revision in Section 110-5.
PANEL RECOMMENDATION: Accept as Revised:
I Aoa "copper" to the third tablular column.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
J
Table 400-4, Note No. 6: Accept
CMP 6
SUBMITTER: R. Drgste, National Elevator Industry, Inc.
FROPO~AC~
' " 67 Reyise the f i r s t paragraph as follows:
~ o r
traveling cables for operating control and signal
circuits shall contain non-meta11~c f i l l e r s as necessary to
maintain concentricity. Centrally located steel supporting
members are supplied as needed for suspension methods described
in Section 620-41.
SUBSTANTIATION: The information on "Note 6" does not comply
wlth the statements of 620-41 which permits three methods of
traveling cable support.
The present.Note 6 states that a traveling cable shall have
non-metallic f i l l e r s or a steel supporting f i l l e r . The
non-metallic f i l l e r s are used by manufacturers with and without
steel support. The standard steel is not a supporting f i l l e r .
Fillers are used to round out (equalize) the conductor layup.
PANEL RECOMMENDATION: Accept as Revised.
First sentence of proposal is to replace existing f i r s t
sentence of Note 6. Second sentence of Proposal is. rejected.
Also, delete the word " f i l l e r s " and replace with "members" in
the existing second and third sentences of Note 6. Revised
f i r s t paragraph of Note 6 to read as follows:
6. Elevator traveling cables for operating control and signal
circuits shall contain nonmetallic f i l l e r s as necessary to
maintain concentricity. Cables exceeding 100 feet between
supports shall have steel supporting members except in locations
subject to excessive moisture or corrosive vapors or gases.
Where steel supporting members are used, they shall run straight
through the center of the cable assembly and shall not be cosied
with the copper strands of any conductor.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Table 400-4: Reject
CMP 6
SUBMITTER: August Lukaslewicz, Cornish Wire Products
~ 6 4 ,
In the "Type Letter" column add SVR for vacuum
cea--T'6-an'~-cords; add SJR for junior hard service cord; and, add SR
for hard service cord. In the "Insulatlon" and "Outer Covering"
columns for vacuum cleaner cord, junior hard service cord, and
hard service cord add the words "Thermoplastic Elastomer."
SUBSTANTIATION: Electrical wires insulated and jacketed with
thermoplastic elastomers require a new class designation for the
following reasons:
I . Chemistry: The chemical structure and characteristics of
thermoplastic elastomers differ significantly as compared to
other thermoplastic materials. Thermoplastic elastomers are
chemically cross-linked yet remain thermoplastic. Thermoplastic
elastomers represent a new class of block copolymers designed
for wire and cable applications offering properties not
previously available in a single polymer.
2. Performance: The performance of thermoplastic elastomers
is generally superior to other thermoplastic materials,
specifically in low and high temperature performance, abrasion
resistance and in electrical performance. Thermoplastic
elastomers are almost equivalent to rubber compounds in
performance characteristics.
3. Aesthetics: Unlike other thermoplastic materials,
thermoplastic elastomers have the feel and appearance of
rubber. Thermoplastic elastomers can easily be mistaken for
rubber, therefore, a separate class designation is in order.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 65, Table 400-4.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Table 400-4, Note No. 6: Accept
CMP 6
SUBMITTER: R. Droste, National Elevator IndUstry, Inc.
PROPOSAL: 68 Delete the f i r s t three lines of the second
and substitute the following:
"Type E, EO, EN, ET, ETP, ETLB, and ETT elevator cables shall
be permitted to contain No. 20 to No. 14 gage insulated
conductors. In addition, they may have incorporated in the
construction No. 20" . . . , etc.
SUBSTANTIATION: ~rticle 620-12(a)-(2) permits No. 20 gage
conductors for operating control and signal circuits. The
107
I
subject article restricts this use to a shielded pair.
PANEL RECOMMENDATION: Accept as Revised:
Delete "gage" and replace with "AWG." Add "AWG" after "No. 20"
in the second sentence.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
400-5: Reject
CMP 6
SUBMITTER: Greg Batie, Seattle, WA
72 4 0 0 - 5 . Ampacity of Flexible Cords and Cables.
l'~BT~-~O-5 gives the allowable ampacity for not more than 3
current-carrylng conductors in a cord. I f the number of
current-carrying conductors in a cord is from 4 to 6, the
allowable ampacity of each conductor shall be reduced to 80
percent of the values for not more than 3 current-carrying
conductors in the table (except in theaters and similar
locations). A conductor used for equipment grounding and a
neutral conductor which carries only the unbalanced current from
other conductors.
SUBSTANTIATION: In stage lighting systems there are usually
more than 3 current-carrying conductors in multi-conductor cords
between the grid terminal boxes and the lighting receptacles.
The number of circuits are required to give the lighting
designer additional F l e x i b i l i t y in circuiting the lighting
fixtures, not because of greater loading.
I t does not make sense to require circuit derating in a stage
lighting system, due to the fact that there is a large diversity
factor in the number of f u l l y loaded circuits at any time.
There is also a minimal probabllity:that enough circuits will be
loaded long enough to cause an elevated temperature in the cord.
In most theatre projects the precedence has been not to derate
the stage circuit conductors, in accordance~with Article 400-5.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ONPANEL RECOMMENDATION: UnanimouslyAffirmative.
Table 400-4, Note No. 7: Reject
CMP 6
SUBMITTER: R. Droste, National Elevator Industry, Inc.
I~ITO!~T~TTL-~. 69 Omit present wording of Note 7 and substitute the
folIowlng:
"A separate conductor In these cables shall be available for
grounding purposes only."
SUBSTANTIATION: This note refers to "a third conductor in these
(elevator) cables is for grounding purposes only." An elevator
cable has a multitude of conductors. A "third conductor" has no
meaning.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Note 7 is not applicable to elevator cables in
Table 400-4.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Tables 400-4 and 400-5: Accept
CMP 6
SUBMITTER: Austin D. Wetherell, Underwriters Laboratories Inc.
~ 7 0
Substitute the word "thermoset" for the word
ih Notes 6, 8 (line 4 only), and 9 to Table 400-4;
Table 400-4 in its entirety; and Table 400-5 column headings.
Table 400-4, outer covering on Types SVO, SJO and SO, change
"oil resistant compound" to "oil resistant thermoset."
Add new types to Table 400-4 as follows:
Trade Name
T~pe Letter
Vacuum Cleaner SV00
Cord
SVTO0
Junior Hard
Service Cord
Hard Service
Cord
Insulation
Oil Resistant
Thermoset.
Oil Resistant
Thermoplastic
or Thermoset
SJO0
Oil Resistant
Thermoset
SJTO0
Oil Resistant
Thermoplastic
or Thermoset
SOD
Oll Resistant
Thermoset
'
STO0
Oil Resistant
Thermoplastic"
or Thermoset
400-5: Accept
CMP 6
SUBMITTER: R. Droste, National Elevator Industry, Inc,
73 Changethe second sentence to the following:
number of current carrying conductors in a. cord exceeds
3, the maximum allowable load current of each conductor shall
be reduced as shown in the following table:
Number of Conductors Percent of Values in Table 400-5
4 through 6
-"
80
7 through 24
70
25 through 42
60
43 and above
50
Comments
All
other
columns
identical
to SVO
All
other
columns
identical
to SVTO
All
other
columns
identical
to SO0
All
other
columns
identical
to SJTO
All
"other
columns
identical
to SO
In addition to the above, Table 400-5 should be revised to
recognize size No. 20 wire.
SUBSTANTIATION: ManyFlexible Cords and/or cables are listed in
Tables 400-4 as having 2 or more conductors. The ampacity
rating described in Table 400-5 does not recognize cords/cables
or more than 3 conductors.
PANEL RECOM~IENDATION: Accept as Revised.
The CMP accepts the revision to change the second sentence and
add the table as submitted.
In addition, revise Table 400-5 to include No, 20 AWG
conductors and a t r i p l e asterisk note as follows:
AWG
At
B+
20
B***
7***
*** Elevator cables only.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
All
other
columns
identical
to STO
400-5: Reject,
CMP 6
Secretary's Note: I t was the action of the Correlating
Committee that action regarding the second paragraph of Section
400-5 will have to be correlated with proposals for Section
250-60.
SUBMITTER:" RaymondKoster, Sheldon, IA
IqTOI~OSA
' ~-~
•. 74 Amendthe second paragraph as follows:
~ a
single conductor is used for both equipment 9r6und
•and" to carry unbalanced current from other conductors, as
provided for in Section 250-60 for electric clothes dryers and
electric ranges, i t "shall" be considered as a current carrying
conductor.
SUBSTANTIATION: A grounded conductor in my opinion should be
considered as a current carrying conductor in the article.
Simply because i t does carry a current. I t carries the
unbalanced current from the other conductors. I t is essential
in the starting and running of electric ranges and electric
clothes dryers. I t usually doesn't carry as much current as the
phase conductors, but i t does carry a certain amount of current.
Referring to the Notes to Tables 310-16 through 310-19. Note
lOB states that in a 3-wlre circuit consisting of 2-phase wires
and a neutral of a 4-wire 3-phase system. The common (grounded)
conductor carries approximately the same current as the other
conductors and shall be counted in determining ampaclties.
Because of this, i t is my suggestion that the wording in
Article 400-5 be changed from 'shall not' to 'shall be
considered a current carrying conductor.'
For the simple reason
i t does carry a current.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting co(mnent is not persuasive as to
necesslty.
VOTE ON PANEL RECO~ENDATION: UnanimouslyAffirmative.
SUBSTANTIATION: 1. Based on test work and discussion with
users, manufacturers, and inspection authorities, UL has
declined to List "Rubber" cords employing elastometric (rubber)
compounds which were not thermoset. Consequently, there are
proposals to revise the 1978 NEC to recognize new types
employing "thermoplastic elastomers." The above revisions are
necessary in order to clearly differentiate the three types.
2. To make intent clearer.
3. UL has Listed these new types to give recognition to cords
with oil resistant insulations as well as Jackets.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
400-5: Accept
CMP 6
SUBMITTER: Peter Pollak, The Aluminum Association
!BIT(~B-O~L-~. 71
In the f i r s t sentence insert "copper" following
l~-carrying
.... "
SUBSTANTIATION Thls proposal is submitted to c l a r i f y the proper
conductor for the application. Makes clearer the fact that the
~conductor is to be copper. The panel is referred to the
proposed revision in Section 110-5.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOI~ENDATION: UnanimouslyAffirmative.
108
/
/
revisions in Article 410, I am of the opinion that they describe
satisfactory applications for flexible cord.
SEGALL: I am voting to approve the proposal. Panel 21 who
has the Jurisdiction for Article 410, has voted to affirm the
proposals to Panel 21 in a revised form. Thls new form will
recognize the use of cord and plug connections under a system of
proper Identification by a recognized testing agency such as UL.
Again I wish to emphasize that all of the manufacturers of
this equipment are getting wide acceptance of these open space
office systems and they are being installed and widely accepted
throughout the United States and Canada. Becauseo f this
acceptance and demand I feel that there should be some control
through the NEC for the electrical components of the system.
Panel 6 will have to have some form of correlatin with Panel
21 and'for thls reason I feet that CMP 6 should reverse i t s e l f
on this Proposal and vote for the adoption of the proposal as
written with the correction as to the Section references to
conincide with the new numbers proposed by CMP 21.
Table 400-5: Reject
CMP 6
SUBMIT~ER: Peter Pollak, The Aluminum Association
l~TOl~O'S'~-~.• 75 Add the following note to Table 400-5:
~
The above ampacities are for copper conductors."
SUBSTANTIATION This proposal is submitted to clarify the proper
conductor for the application. Makes clearer the fact that the
conductor is to be copper. The panel is referred to the
proposed revision in Section 110-5.
PANEL RECOMMENDATION: Reject.
:
ee anel action on Proposal No. 71, Section
400-5.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Table 400-5: Reject
CMP 6
SUBMITTER: R. Oroste, National Elevator Industry, Inc.
76 T h i s table should be in line with Tables 310-16
~6--3~!X~CT9 to show different ampacity ratings for conductors with
rubber covered insulation cempared to thermoplastic insulation.
The table should also provide ampacity rating for size No. 20
AWGwire.
SUBSTANTIATION: Section 340-7 states that ampacities of a Type
TC tray cable (multiple conductors) should be determined from
Table 400-5, etc.
In Table 400-5 the rubber insulated conductors (temp. rating
60°C) have the same ampacity rating as thermoplastic conductors
(temperature rating gO°C).
Table 400-5 does not cover size No. 20 AWGconductor. Table
400-4 does.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not agree with the supporting
~ent.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
0
400-7(a)(3) and (6) (HOD1978 NEC): Reject
CMP 6
SUBMITTER: Technical Subcommittee on Definitions of Stationary
X~6TT~s
PROPOSAL: 78 Delete Section 400-7(a)(3) and revise (6) to ,
rea--e-a-dT~mconnection
,
of appliances to f a c i l i t a t e their frequent
interchange."
SUBSTANTIATION: The Technical Subcommittee found that some
requirements for fixed appliances, portable appliances, and
stationary appliances were based on different meanings of the
terms. These differences arise from the intent of the authors
of the requirements at the time the text is adopted. In some
cases the requirements are based on the means of electrical
connection of the appliance to the supply circuit. In other
instances the requirements involve the physical location of the
appliance. The TSC noted some requirements that appeared to
involve both meanings and s t i l l others where I t was not clear
from the wording what the concerned Code Making Panel intended.
The Technical Subcommittee suggests that the requirements
'pertaining to appliances differentiate between those that are
necessitated by vlrtue of the method of the electrical
connection and those that relate to the physical location of the
appliance. With regards to the electrical connections, i t is"
suggested that this be accomplished either by the use of a cord
and plug or by a permanent connection, that is, without the use
of a cord and plug. Requirements pertinent to appliance
location involve physically fastening the appliance in place by
means other than the e~ectrical connection or locating the
appliance in dedicated space. These appliances may be moveable
within the space. The result of either approach is to place the
appliance on a specific c i r c u i t .
The Technical Subcommittee believes that i f these delineations
were scrupulously observed and universally applied throughout
the Code, both in the drafting of new requirements pertaining to
appliances and revising current appliance requirements, the
confusion surrounding the interpretation and application of the
three terms under review would disappear. Moreover the TSC
believes that adherence to this understanding would obviate the
need for the three terms.
As an aid to clarifying the intent of the requirements, the,
TSC suggests that as required, the following terms or phrases be
employed: permanently connected; cord- and plug-connected;
fastened in place; or located to be on a specific circuit.
There are requirements where in the opinion of the TSC the
deletion of terms "fixed", "portable", or "stationary" will in
no way affect the requirements. In such cases, i t is
unnecessary to substitute any of the foregoing.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's Intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
400-7(a)and(b): Reject
CMP 6
SUBMITTER: Stephen D. Channer, Business and Institutional
~Manufacturer's
Assn., BIFMA
PROPOSAL: 77 Add the following to (a):
. ~ 0 )
connection of office furnishings, appliances and
lighting as permitted by Sections 410-100, 410-101, and 410-102."
Revise (b) as follows:
Delete "and" after (a)(6) and add "and (a)(10)" after (a)(8).
SUBSTANTIATION: This proposal concerns i t s e l f with wiring
systems as provided by members of our industry with office
furniture systems that are now being used extensively in offices
throughput the United States. Although not exclusively, office
furniture systems are primarily used in areas referred to as
"open plan" or "landscape" office layouts.
Within our industry, office ,systems furniture has grown in
popularity to a great extent over the past several years. Much
of the popularity stems from the advantages of portablity and
ease of rearrangement. Today the sales of this type of
furniture are well over 300 million dollars annually and
growing. Due to energy conservation requirements, users have
demanded the inclusion of task and ambient lighting with this
type of furniture. Current industry estimates show that
approximately 80 percent of all office furniture systems sold
contain electrical power. When such power is provided by
manufacturers within our association, safety is foremost in
their consideration and all wiring systems have.been or are in
the process of being submitted to and listed by Underwriters
Laboratories or other nationally recognized testing laboratories.
Our industry is very proud of its concern for product safety
and performance and the good record that i t currently enjoys.
Our purpose in submitting the enclosed proposal to the National
Fire Protection 'Association is to establish a category within
the National Electrical Code that deals specifically with
products made within our industry that contain wiring systems
and to provide in "writing the standard of quality that must be
adhered to by those making such systems.
Your review and favorable consideration of this proposal will
be very much appreciated by the business and institutional
furniture industry.
(
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP feels proposal is not in consistence with
5ectlon 400-8.
VOTE ON PANEL RECOMMENDATION:
AFFIR~t~IIVE: 9.
NEGATIVE: Coffey, Segall.
EXPLANATION OF VOTE:
COFFEY: I oppose the panels recommendation to reject this
proposal because I do no agree with the Panel Comment that the
proposal is inconsistent with Secton 400-8. Section 400-8 talks
about not using flexible cords as a substitute for fixed wiring,
running in through walls, ceilings or floors, doorways, windows
or similar openings, attached to building surfaces or where
concealed behind building walls. A review of the proposed
Section 410-100, 410-101 and 410-102 under consideration by Code
Panel 21 indicates the use of flexible cord would be limited to
office furnishings, appliances and lighting which are free
standing. In addition, the panels involved are also limited in
height to approximately 7 feet and in no instance do they run
from floor to ceiling and where more than one panel is involved,
they are mechanically connected and not' Joined together by Just
a length of flexible cord. After reviewing the proposed
l
400-7(c)-(New): Reject
CMP 6
SUBMITTER: J . J. Kark, National Electrical Manufacturers Assn.
PlTOI~[-~.- 79 Add new (c) as follows:
- - - ( - c ~ l e x i b l e cord connections may be made directly to the
load end terminals of busway plug-in devices,, providing such
connections include a suitable tension take-up device on the
cord to satisfy the requirements of Section 400-10.
SUBSTANTIATION: The phrasing of paragraph 400-7(b) presumes
that a flexible cord with attachment plug will be plugged into a
conveniently located receptacle outlet at a convenient fixed
location. In actual practice, appliances may have to be moved
from place to place in locations where the only available power
supply might be from a run of plug-in busway.
For this application, s t r i c t interpretation of 400-7(b)
requires the introduction of a costly but unnecessary
intermediate connection between the flexible cord and the
plug-in device.
1. Cord-to-buswayconnections are permitted per Section 364-8
but no guidelines are included for the make-up of such
connections.
2. Proposed400-7(c) satisfies the intent of 400-7(b); the
busway plug-in device serves as the attachment plug--and the
busway plug-in opening serves as the receptacle outlet.
3. Proposed400-7(c) eliminates the unnecessary intermediate
109
connection in the sequence: flexible cord--to attachment
plug--to receptacle outlet--to load terminals of busway plug-in
device - to plug-in jaws--to bus bars of busway.
PANELRECOMMENDATION: Reject.'
PANEL COM~iENT: Material is adequately covered in Section 364-8.
~l)InL'-OIl-l~Al~'~ RECOM~IENDATION:
AhFIRMATIVE: 8.
NEGATIVE: Conley, Oannot, Lipsey.
EXPLANATION OF VOTE:
CONLEY: The proposal should be revised by changing "May
to "shall be permitted to" in the f i r s t line.
Thls is a safe and suitable means of making connections to
busway plug-in devices as explained in the substantiation, but
i t is not adequately covered in Section 364-8 as the Panel
Comment claims.
JANNOT: I disagree with the Panel Comment that the materi~1
is adequately covered in Section 364-8. The submitter has
stated that the NEC now requires the complex arrangement
detailed in item 3 of his Substantiation. The consensus of the
Panel was that this is not required and that cords can be -- and
are now -- connected directly to the plug-in devices.
Obviously, then, the NEC as i t is now written is subject to
misinterpretation and, in my opinion, accepting this proposal
would clarify this point.
LINSEY: I do not agree with the Panel Comment that this
mate~al is properly covered by Section 364-8. The submitter,
NEMA, states that the present Code requires the arrangement
outlined in paragraph 3 of his Substantiation. The Panel f e l t
that this is not required and that cords can and are now being
connected directly to the'plug-ln devices. I t appears that the
Code, as now wHtten is being misunderstood. The acceptance of
the proposal w o u l d clarify this.
400 Part C: Reject
CMP B
SUBMITTER: TSC-Nominal Voltage
83 Delete the word "nominal" from heading.
~'I]I~'FA]qTIATION: Changerecommended for clarification and to
obtain conformance with present practice and uniformity within
the Code.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
400-31(a): Reject
CMP 6
SUBMITTER: Peter Pollak, The Aluminum Association
84
In the f i r s t sentence following "No~ 8" insert
~ o r
No. 6 aluminum. . . .
SUBSTANTIATION This proposal is submitted to clarify the proper
slze equivalent of aluminum conductor for the application. The
size limitation is based upon an ampacity requirement which can
be met with an aluminum conductor sized to provide the required
ampacity. The panel is referred to the proposed revision in
Section 110-5.
PANEL RECOMMENDATION: Reject.
:
ee Panel action on Proposal No. 84A, Section
400-31(a).
VOTE ON PANELRECOHMENDATION: UnanimouslyAffirmative.
.,
400-31(a): Accept
CMP 6
SUBMITTER: CMP 6
84A Revise as follows:
--'X'~T-C-Bnductors. The conductors shall be No. 8 AWGcopper or
larger and sha!l employ flexible stranding.
SUBSTANTIATION: To clarify the proper conductor type for the
application.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unaniinously Affirmative.
400-9: Reject
CMP 6
SUBMITTER: IdahoChapter, IAEI
~ 8 0
In Section 400-9 the third line down change the
wor--o-f-d~-"ITard-service" to "hard-usage."
SUBSTANTIATION: This will make the wording here in 400-9
compatible wTth the wording in the Table 400-4. There will be
no question of the type flexible cords that are permitted to be
repaired after i n i t i a l installation.
PANEL RECOI~MENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's Intent. The intent of Section 400-9 is to permit the
splicing o f hard-service cord only, such as Types S, SO, ST, and
STO.
VOTE ON PANELRECOMMENDATION:
A~FIRMATIVE: 10.
NEGATIVE: Hogan.
EXPLANATIONOF VOTE:
HOGAN: I would change my vote on the proposal i f the words
"hard service flexible cords" were revised to read as fol}ows:
"flexible hard service cords." This would then pin down
precisely what the panel says is intended and .would also answer
the proposer's aim.
.
•
402-1: Accept
CMP 6
Secretary's Note: I t was the action of the Correlating
C~m~nittee that the Panel review this Proposal for possible
conflict withTable 402-3 which mentions other kinds of
conductors,
o
SUBMITTER: Peter Poliak,'The Aluminum Association
PIIOIIIIS'XL-T.
• 85 Changethe sentence to read as follows: This
~covers
general requirements and construction
specifications for copper fixture wires."
SUBSTANTIATION This proposal is submitted to clarify the proper
slze equivalent of aluminum conductor for the application.
Makes clearer the fact that the conductor is to be copper. The
panel is referred to the proposed revision In Section 110-5.
PANEL RECOMMENDATION: Accept.
vuIE DN PANELRECOMMENDATION:
AFFIRMATIVE: g.
NEGATIVE: Coffey, Hogan.
EXPLANATION OF VOTE:
COFFEY: I oppose the Panel Recemmendation to accept this
proposal because I feel the introduction of the limitation
copper fixture wires in the scope of this Article is not
correct. This Article covers the installation of a11 fixture
wires and.while at present,, fixture wires are limited to copper
conductors, this limitation is rightfully stated in Section
110-5 of the Code and i f the panel feels further clarification
is necessary, i t could appear in another Section of Article 402,
such as 402-5 or 402-6.
HOGAN: The heading for this Article is Fixture Wires. I t
would seem to me that anyone using this book would take from
that heading that any restrictions or provisions for fixture
wires would be found in this Article. By accepting this
proposal you have limited the Scope of this Article to copper
fixture wires and have l e f t the door open for any one to
manufacture fixture wires of any material and there wlll be no
regulations covering them. The Scope of this Article is not
Just copper fixtures wires; i t is all fixture wires now and
forever.
400-I0: Accept
CMP 6
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
)ITOP1~']~-~.. 81 Add a sentence as follows:
-'-l~TexT~le cords shall, where passing through holes in outlet
boxes, covers or similar enclosures, be protected by approved
bushings or f i t t i n g s especially designed for the purpose.
SUBSTANTIATION: Flexible cords or cables should be protected
from sharp ~ges where they pass through holes in sheet metal
covers or boxes. UL standards require a bushing or protection
where passing through a sheet metal hole and this same
protection should be given to field installed cords.
PANEL RECOMMENDATION: Accept as Revised:
Add a new section as follows:
400-14. Protection From Damage. Flexible cords and cables
shall be protected by bushings or f i t t i n g s where passing through
holes in covers, outlet boxes or similar enclosures,
VOTE ON PANELRECO~IENDATION: UnanimouslyAffirmative.
AOO-lO:ReJect
CMP
SUBMITTER: SouthwesternSection IAEI
PRuPOSAL: 82 Add the following sentence to Section 400-10:
Flexlble cords shall, where passing through holes in outlet
boxes, covers or similar enclosures, be protected by approved
bushings or f i t t i n g s especially designed for the purpose.
SUBSTANTIATION: Flexible cords or cables should be protected
fromsharp e~ges where they pass through holes in sheet metal
covers or boxes. UL standards require a bushing or protection
where passing through a sheet metal hole and this same
protection should be given to field installed cords.
PANEL RECOMMENDATION: Reject.
PANEL ~Ui~MENT: See Panel action on Proposal No. Bl, Section
400-10.
VOTE ON PANELRECOte~ENOATION: UnanimouslyAffirmative.
ARTICLE402 -- FIXTURE WIRES
402-3:Accept
CMP 6
SUBMITTER: TSC-Nominal Voltage
~ 8 6
Revise second sentence as follows:
~xture
wires listed In Table 402-3 are all suitable for
service at 600 volts, nominal or less unless otherwise specified.
SUBSTANTIATION: Changerecommended for clarification and to
obtain conformance with present practice and uniformity within
the code.
PANEL"RECO)eiENDATION: ACcept as Revised:
I "Delete the words "or less."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
110
connection in the sequence: flexible cord--to attachment
plug--to receptacle outlet--to load terminals of busway plug-in
device - to plug-in jaws--to bus bars of busway.
PANELRECOMMENDATION: Reject.'
PANEL COM~iENT: Material is adequately covered in Section 364-8.
~l)InL'-OIl-l~Al~'~ RECOM~IENDATION:
AhFIRMATIVE: 8.
NEGATIVE: Conley, Oannot, Lipsey.
EXPLANATION OF VOTE:
CONLEY: The proposal should be revised by changing "May
to "shall be permitted to" in the f i r s t line.
Thls is a safe and suitable means of making connections to
busway plug-in devices as explained in the substantiation, but
i t is not adequately covered in Section 364-8 as the Panel
Comment claims.
JANNOT: I disagree with the Panel Comment that the materi~1
is adequately covered in Section 364-8. The submitter has
stated that the NEC now requires the complex arrangement
detailed in item 3 of his Substantiation. The consensus of the
Panel was that this is not required and that cords can be -- and
are now -- connected directly to the plug-in devices.
Obviously, then, the NEC as i t is now written is subject to
misinterpretation and, in my opinion, accepting this proposal
would clarify this point.
LINSEY: I do not agree with the Panel Comment that this
mate~al is properly covered by Section 364-8. The submitter,
NEMA, states that the present Code requires the arrangement
outlined in paragraph 3 of his Substantiation. The Panel f e l t
that this is not required and that cords can and are now being
connected directly to the'plug-ln devices. I t appears that the
Code, as now wHtten is being misunderstood. The acceptance of
the proposal w o u l d clarify this.
400 Part C: Reject
CMP B
SUBMITTER: TSC-Nominal Voltage
83 Delete the word "nominal" from heading.
~'I]I~'FA]qTIATION: Changerecommended for clarification and to
obtain conformance with present practice and uniformity within
the Code.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
400-31(a): Reject
CMP 6
SUBMITTER: Peter Pollak, The Aluminum Association
84
In the f i r s t sentence following "No~ 8" insert
~ o r
No. 6 aluminum. . . .
SUBSTANTIATION This proposal is submitted to clarify the proper
slze equivalent of aluminum conductor for the application. The
size limitation is based upon an ampacity requirement which can
be met with an aluminum conductor sized to provide the required
ampacity. The panel is referred to the proposed revision in
Section 110-5.
PANEL RECOMMENDATION: Reject.
:
ee Panel action on Proposal No. 84A, Section
400-31(a).
VOTE ON PANELRECOHMENDATION: UnanimouslyAffirmative.
.,
400-31(a): Accept
CMP 6
SUBMITTER: CMP 6
84A Revise as follows:
--'X'~T-C-Bnductors. The conductors shall be No. 8 AWGcopper or
larger and sha!l employ flexible stranding.
SUBSTANTIATION: To clarify the proper conductor type for the
application.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unaniinously Affirmative.
400-9: Reject
CMP 6
SUBMITTER: IdahoChapter, IAEI
~ 8 0
In Section 400-9 the third line down change the
wor--o-f-d~-"ITard-service" to "hard-usage."
SUBSTANTIATION: This will make the wording here in 400-9
compatible wTth the wording in the Table 400-4. There will be
no question of the type flexible cords that are permitted to be
repaired after i n i t i a l installation.
PANEL RECOI~MENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's Intent. The intent of Section 400-9 is to permit the
splicing o f hard-service cord only, such as Types S, SO, ST, and
STO.
VOTE ON PANELRECOMMENDATION:
A~FIRMATIVE: 10.
NEGATIVE: Hogan.
EXPLANATIONOF VOTE:
HOGAN: I would change my vote on the proposal i f the words
"hard service flexible cords" were revised to read as fol}ows:
"flexible hard service cords." This would then pin down
precisely what the panel says is intended and .would also answer
the proposer's aim.
.
•
402-1: Accept
CMP 6
Secretary's Note: I t was the action of the Correlating
C~m~nittee that the Panel review this Proposal for possible
conflict withTable 402-3 which mentions other kinds of
conductors,
o
SUBMITTER: Peter Poliak,'The Aluminum Association
PIIOIIIIS'XL-T.
• 85 Changethe sentence to read as follows: This
~covers
general requirements and construction
specifications for copper fixture wires."
SUBSTANTIATION This proposal is submitted to clarify the proper
slze equivalent of aluminum conductor for the application.
Makes clearer the fact that the conductor is to be copper. The
panel is referred to the proposed revision In Section 110-5.
PANEL RECOMMENDATION: Accept.
vuIE DN PANELRECOMMENDATION:
AFFIRMATIVE: g.
NEGATIVE: Coffey, Hogan.
EXPLANATION OF VOTE:
COFFEY: I oppose the Panel Recemmendation to accept this
proposal because I feel the introduction of the limitation
copper fixture wires in the scope of this Article is not
correct. This Article covers the installation of a11 fixture
wires and.while at present,, fixture wires are limited to copper
conductors, this limitation is rightfully stated in Section
110-5 of the Code and i f the panel feels further clarification
is necessary, i t could appear in another Section of Article 402,
such as 402-5 or 402-6.
HOGAN: The heading for this Article is Fixture Wires. I t
would seem to me that anyone using this book would take from
that heading that any restrictions or provisions for fixture
wires would be found in this Article. By accepting this
proposal you have limited the Scope of this Article to copper
fixture wires and have l e f t the door open for any one to
manufacture fixture wires of any material and there wlll be no
regulations covering them. The Scope of this Article is not
Just copper fixtures wires; i t is all fixture wires now and
forever.
400-I0: Accept
CMP 6
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
)ITOP1~']~-~.. 81 Add a sentence as follows:
-'-l~TexT~le cords shall, where passing through holes in outlet
boxes, covers or similar enclosures, be protected by approved
bushings or f i t t i n g s especially designed for the purpose.
SUBSTANTIATION: Flexible cords or cables should be protected
from sharp ~ges where they pass through holes in sheet metal
covers or boxes. UL standards require a bushing or protection
where passing through a sheet metal hole and this same
protection should be given to field installed cords.
PANEL RECOMMENDATION: Accept as Revised:
Add a new section as follows:
400-14. Protection From Damage. Flexible cords and cables
shall be protected by bushings or f i t t i n g s where passing through
holes in covers, outlet boxes or similar enclosures,
VOTE ON PANELRECO~IENDATION: UnanimouslyAffirmative.
AOO-lO:ReJect
CMP
SUBMITTER: SouthwesternSection IAEI
PRuPOSAL: 82 Add the following sentence to Section 400-10:
Flexlble cords shall, where passing through holes in outlet
boxes, covers or similar enclosures, be protected by approved
bushings or f i t t i n g s especially designed for the purpose.
SUBSTANTIATION: Flexible cords or cables should be protected
fromsharp e~ges where they pass through holes in sheet metal
covers or boxes. UL standards require a bushing or protection
where passing through a sheet metal hole and this same
protection should be given to field installed cords.
PANEL RECOMMENDATION: Reject.
PANEL ~Ui~MENT: See Panel action on Proposal No. Bl, Section
400-10.
VOTE ON PANELRECOte~ENOATION: UnanimouslyAffirmative.
ARTICLE402 -- FIXTURE WIRES
402-3:Accept
CMP 6
SUBMITTER: TSC-Nominal Voltage
~ 8 6
Revise second sentence as follows:
~xture
wires listed In Table 402-3 are all suitable for
service at 600 volts, nominal or less unless otherwise specified.
SUBSTANTIATION: Changerecommended for clarification and to
obtain conformance with present practice and uniformity within
the code.
PANEL"RECO)eiENDATION: ACcept as Revised:
I "Delete the words "or less."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
110
Tin-coated Copper conductor for 150°C-600V service.
c. HALARinsulated cable passes IEEE 383, "Standard for Type
Test of Class IE Electric Cables...for Nuclear Power Stations"
when subjected to radiation aging and conditions designed to
simulate a loss of coolant accident (LOCA).
d. HALARinsulated cable is approved for "Fluoropolymer
insulation for use on Public Conveyance MR-73" for the Montreal
Metro. The specification cal]s for oven aging for 96 hours at
200°C among its tests.
e. HALARinsulated cable manufactured by Revere Corporation
of America passes a variety of tests required by IPCEA~19-81 and
is qualified for insulation for nuclear power stations.
f . HALARinsulated cable, produced by BOFA, is recognized by
Sweden's SEMIKOstandards for 155°C and 600V service.
g. HALARinsulated wire is recognized by Canadian Standard
for App]iance Wire at 105°C and 150V for a 5 mil wal].
h. HALARinsulated wire Is recognized by the Electrical Trust
of South Australia for 150°C 250V service and is therefore
reciprocally recognized for use throughout Australia.
In addition, the use of ECTFE as insulation f o r fixture wire
will be substantiated by a Fact Finding Report by the
Underwriters Laboratories. The investigation is underway with a
preliminary report on the short term and 30 day aging expected
by December ist and the final report in ]ate January.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Pane] action on Proposal No. 89A, Table
402-3. Accept CMP 6 Proposal 89A and refer to CMP 16.
VOTEON PANELRECOVJ~ENDATION: UnanimouslyAffirmative.
Table 402-3: Accept
CMP 6
SUBMITTER: John E. Conley, General Electric Co.
87 Under Type Letter "AF," revise third column'as
~
ImpreGnated
18-14
-30
Asbestos or . . . .
20
10
"SUBSTANTIATION: This proposal was accepted for inclusion in the
19/8 NEC but was Imbroperly:transcribed for printing; therefore
the printed version of the 1978 NEC does not correctly reflect
the action of the Cammittee. Refer: Proposal No. 4 page 213 of
1978 Preprint NEPA70PR78.
PANEL RECOMMENDATION: Accept.
VUlt UN PANELR~COMMENDATION: UnanimouslyAffirmative.
CO~IENT ON VOTE:
COFFEY: I suggest that when presenting this proposal in the
preprint for public comment, that the ent4~e third column of
Table 402-3 for Type AF fixture wire be included.
Table 402-3: Accept
CMP 6
SUBMITTER: Cutter D. Palmer, Wilmington, DE
l}ITOl~--~." 88 For wire types KF-1 and KFF-1, revise
X~FTcal~ions Provisions column to read: "Fixture wire, and as
permitted in Sections 725-16 and 760-16. Limited to 300 vo]ts."
For wire types KF-2 and KFF-2, revise Applications Provisions
column to read: "Fixture wire, and as permitted in Sections
725-16 and 760-16."
SUBSTANTIATION: Multiple conductor type KFF-2 cable has been
tested by Underwriters Laboratories in Northbrook, I l l i n o i s , in
both the modified Steiner Tunnel Test and the IEEE-383 vertical
tray test. In both tests f u l l cable trays were subjects to the
f l m e . Flame spread and smoke values were the lowest of any
cables previously tested. Enclosed is a copy of a letter f r ~
UL with these test results. Also enclosed is a copy of the UL
Fact Finding Investigation which was the basis for listing these
wire types in the 1978 NEC.
Hundreds of mil]ions of feet of wire with the KFF-2 insulation
system have been used' for approximately 10 years in con~ercial
and military aircraft as well as the wiring for most space
vehicles and missiles. For instance, each Lockheed L-lOll has
approximately 650,000 feet of this wire installed as open,
/
unjacketed bundles, both in the fuselage and in the SWAMP
(special wind and moisture problems) areas. The airlines report
type KFF-2 wire to be essentially malntenance'free in spite of
temperature extremes, high vibration, exposure to hydraulic,
deicing, fuels, etc. I t also meets the FAA proposed
\
requirements for extremely low smoke generation.
PANEL RECOMMENDATION: Accept as Revised:
CMP 6 rejects f i r s t paragraph as Sections 725-16(b) and
760-16(b) do not permit conductors limited to 300 volts. CMP 6
accepts second paragraph to revise "Applications Provisions"
column for Types KF-2 and KFF-2.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Table 402-3: Accept
CMP 6
SUBMITTER: CMP 6
I I~T(~-O~-~.'89A Revise "Applications Provisions" column for
and HFF to read: "Fixture wiring, and as permitted in
Section 725-16."
SUBSTANTIATION: See Proposal No. 89.
PANEL RECOMMENDATION: Accept contingent upon the concurrence of
16.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
CO~ENF DN VUIL:
HOGAN: Since Pane] 16 has rejected their proposal we should
also indicate rejection of this proposal.
Table 402-3 (HOD 1978 NEC): Reject
CMP 6
SUBMIITER: Cutter Palmer, E. I. duPont de Nemours & Co., Inc.,
~TI-~F6~-6n, DE
PROPOSAL: 9 0 Add fixture wife Types KF-1, KF-2, KFF-I, KFF-2
402-3.
Table 402-3 (HOD 1978 NEC): Reject
CMP 6
SUBMITTER: Paul J. Koch, Allied Chemical Corporation,
~ n ,
NJ
PROPOSAL: 89 AmendSection 402--Table 402-3 to add:
Extruded 18-14--20 None 150°C Fixture Wire
302°F and as permitted In
Section 725-16
Poly-ethylene ECTFE Polychlorotrlethylene
fluoroethylene
chlorotriFixture Wire
fluoroFlexible
ethylene
Stranding
SUBSTANTIATION: HALARECTFE Fluoropolymer is a high temperature
resln exceptionally suited for electrical wire insulation. Its
dielectric strength in thin sections is as high as 2000 V/mil,
volume resistivit% of 1015 ohm-cm, dielectric constant measures
2.5-2.6 over a wise temperature and frequency range, and
dissipation factor lower than most dielectrics, varying from
0.0008 at 102 Hz to 0.13 at 106Hz.
In addition HALARhas high tensile strength on the order of
6-7000 psi, is moderately s t i f f and notched impact strength
greater than 20 f t . ]bs. Its cut-through resistance and
abrasion resistance are excellent, which allows i t to withstand
considerable abuse during installation and service. HALAR
insulation will not support combustion in air or in atmospheres
up to 60 percent oxygen. I t chars rather than melts or drips.
I t is inert to acids, bases, and strong oxidizing agents and
does not dissolve or stress crack in any known solvent at
temperatures up to 120°C.. HALARinsulation is capable of
continuous service at 150°C and has a brittleness temperature
less than -80°C.
In support of the above statement v~e offer the following items
for consideration:
a. HALARis recognized as a resin by Underwriters
Laboratories for continuous service at 150°C and for Appliance
Wiring Material, Style 1587, for service up to 125°C--no voltage
specified.
b. HALARpasses the Naval Air Systems CommandMil-W-22759/24
(AS) for Wire, Electric, Fluoropolymer-insulated, Medium Weight,
Tape
KF-1 Aromatic 18-10...5.5
Insulated
Polyimide
Fixture
Tape
Wire
None 200°C Fixture Wiring
392°F Limited to
300 Volts
Solid or KF-2 Aromatic 18-10...8.4
7-Strand
Polyimide
Tape
:
None 200°C Fixture Wiring
392°F and as permitted in
Section 725-16
Tape , KFF-1 Aromatic 18-10...5.5
Insulated
Polyimide
Fixture
Tape
Wire
None 200°C Fixture Wiring
392°F Limited to
300 Volts
Flexible KFF-2 Aromatic
Stranding
Polyimide
Tape
None 200°C Fixture Wiring
392°F and as permitted in
Section 725-16
18-I0...8.4
SUBSTANTIATION: Kapton Tape insulated wire has been used for
several years in aircraft such as the LI011 and other military
and government applications. Kapton's excellent electrical and
mechanical properties, coupled with the ability to consistently
apply the tape uniformly and concentrically over the conductor,
results in reduced insulation thicknesses not possible with
conventional extruded insulations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 88, Table 402-3.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
402-10: Reject
CMP 6
SUBMITTER: O. E. Dillon, Border County Div. IAEI
PR
'O
' -FO-S~AC
' -~
". 91 Add the word "only" after the word "permitted."
~U~IANIIATION: This language is permissive and does not
restrict the use of fixture wires. See the attached opinion* of
the San Diego City Attorney.
*See Border County Div. IAEI substantiation for CMP I Proposal
No. 90 for 110-16(a).
PANEL RECOf~MENDATION: Reject.
PANbL ~UMMhNI: Panel feels subject is adequately covered.
v u } t UN PAflhL RECOMMENDATION: UnanimouslyAffirmative.
111
402-11 Exception: Accept
CMP 6
SUBMITTER: W. R. Hitchens, E. I. du Pont de Nemours & Co.
I~ITO]~-O~TAL-~. 92 Revise as follows:
~ i o n :
As permitted by Section 725-16 for Class 1
circuits and Section 760-16 for f i r e protective signaling
circuits.
SUBSTANTIATION: Table 402-3 (right hand column) permits this
for types of fixture wires covered in 760-16(b). In correlating
changes to the 1978 NEC, I believe the reference to 760-16 in
the Exception to 402-11 was l e f t out in error.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
CHAPTER 9 -- TABLESAND EXAMPLES
Chapter 9, Tables 6, 7 and 8: Accept
CMP 6
SUBMITTER: Alton R. Thompson, Durham, NC
~ROPOSAL: 93 Add to Tables 6, 7 and 8: "No. 8 stranded
~ r s . "
SUBSTANTIATION: Since January 1973, No. 8 solid wire has been
removed from the Nationa] Electrical Code book to be installed
in conduit, except for Article 680. The properties of No. 8
stranded should be listed in Tables 6, 7 and 8.
PANEL RECOMMENDATION: Accept as Revised.
Table 6. Add "sol." after existing "8" and add No. 8 stranded
din~nsions as follows:
8 str. .43
.145 .43x.75 .282 .86 .581
ReviSe Note as follows:
Note - No. 14 to No. 10, solid conductors; No. 8, solid or
stranded conductors; No. 6 and larger, stranded conductors.
Table 7. Add "sol." after existing "8" and add No. 8 stranded
dimensions as follows:
8 str. .325 . 0 8 3 .285 .064 . 3 9 0 .119
Revise Note as follows:
Note: No. 14 to No. 10, solid; No. 8, solid or. stranded; No. 6
and larger, stranded; except AVL where all. sizes are stranded.
Table 8. Add No. 8 stranded properties as follows:
8
16510 7 .0486 .1458 .0167 . 6 5 3 .679 1.07
VOTE ON PANELRECO~MENDATION: UnanimouslyAffirmative.
112
410-X: Reject
CMP 21
SUBMITTER: C. E. Muhleman, Marion IN
,
PROPOSAL: 3
Add new sections to Article 410 Part A as follows:
~current.
Each fixture shall have overcurrent protection
built into the fixture or its cord cap.. The overcurrent device
shall not exceed 150 percent of the fixture load.
410-Overtemperature. Each recessed fixture shall have
overtemperature protection built into the fixture.
410-Location. A permanent lighting fixture shall be installed
in each room or space into which a person can enter.
Exception: Residential living rooms.
SUBSTANTIATION: Proposed "Overcurrent" should prevent small
faults from not being detected by a large overcurrent device and
thus will reduce fires.~
Proposed "Overtemperature" should prevent fires from
overtemperatures such as may be caused from installing thermal
insulation around the fixture.
Proposed "Location" will eliminate some of t~e need for
extension cords, etc., which have attributed to many
electrocutions.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment provided no evidence that
small faults are resulting in fires and therefore the CMP
rejects the proposed requiroment for overcurrent protection. In
Proposal No. 42, CMP 21 has accepted a proposal addressing
overtemperature. Section 210-26(a) already contains
requirements concerning "required lighting fixtures" and this
proposed addition to Article 410 is unnecessary.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
• REPORTOF CODE-MAKINGPANEL NO. 21
ARTICLE 410 -- LIGHTING FIXTURES,.LAMPHOLDERS, LAMPS
RECEPTACLES, AND ROSETTES
410-Editorial (HOD 1978 NEC): Accept
CMP 21
• SUBMITTER: A. KnicKrehm, Los Angeles, CA
]~q~5-O'S'AL~•. I
AmendArticle 410 as follows:
T1-~--2rro-65(a) Removethe words "constructed or."
(2.) 410-65 Add new:
(c) MaximumOperating Temperature. Fixtures shall be, so
installed thaU the maximumoperating temperature of the
component parts of the fixtures will not be exceeded.
(3.) 410-36 Add new third sentence:
Fixtures shall be so designed that the component parts of the
fixtures will not exceed their maximum operating temperature
when the fixture is installed in compliance with this article.
(4.) 410-68 Add new second sentence:
Fixtures shall be so constructed that-the maximum operating
temperature of their component parts will not be exceeded.
SUBSTANTIATION: To insure that the maximum temperatures of
fixture parts are not exceeded. Fixtures are sometimes boxed in
by f i r e resistant materials to comply with f i r e and building
codes. This causes excessive temperatures to fixture parts,
such as "P" rated lamp ballasts. When i t is required to box-in
fixtures suitable low heat equipment is available for fixture
construction.
PANEL RECOMMENDATION: Accept as Revised.
Accept the item (1.) portion of the proposal by deleting the
words "constructed or" from Section 410-65(a).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-4(a): Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
PI~-OPO-SA
' Z-~." 4
See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" i n A r t i c l e
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete the words "shall be approved for the purpose and."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Article 410: Accept
CMP 21
SUBMITTER: "CMP21
PROPOSAL: 1A Rev,iseArticle 410 as follows:
410-14. Makeexisting f i r s t sentence of f i r s t paragraph (a);
relocate balance of f i r s t paragraph; all of paragraph two and
four to new 410-30(c); Relocate third paragraph to new
410-16(9).
410-23. Relocate text to (b) of 410-24.
410-24. Change heading to "Conductors"; make existing text (a)
with t i t l e "Insulation." Delete present (b)l
410-26. Delete heading; relocate 410-26(a) to new 410-28(e)
with t i t l e "Stranding"; relocate 410-26(b) to new 410-28(f) with
t i t l e "Tension."
410-28. Relocate410-28(c) to new 410-30(a). Change t i t l e to
"Lampholders."
410-29. Relocate 410-29(e) to 410-57(b) and change 410-57(b) to
(c); (c) to (d); (d) to (el.
410-30. Change heading to "Cord connected l ampholders and
fixtures."
Relocate 410-30(a) to new 410-16(b);
Relocate 410-30(b) to new 410-28(c);
Relocate 410-30(c) to new 410-28(d);
Relocate 410-30(d) to new 410-14(b);
Change 410-30(e)to (b).
410-32. Relocate to new 410-23.
410-40. Relocate to new 410-16(d).
410-41. Relocate to new 410-16(e).
410-77. Relocate to 4)0-77(b) to new 410-29(e) and revise to
read: Where show cases are cord connected, the secondary
circuit(s) of electric discharge lighting shall be limited to
one show case. Change410-77(c) to 410-77(b).
SUBSTANTIATION: Arranged to place requirements of the same
subject in the same sections.
PANEL RECOMMENDATION: Accept.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-4(a): Reject
CMP 21
SUBMITTER: CMP 21
~ 4 A
In the third paragraph, after the word
"basementsa add "some bathrooms."
SUBSTANTIATION: CMP 21 considers that some bathrooms are damp
locations, and that all bathrooms are damp locations at some
times.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: In re-evaluating this proposal, the CMP cannot
j u s t i f y a damp location fixture to be required in all areas of a
bathroom.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-4(c)(1): Reject
CMP 21
SUBMITTER: Jim Fleshman, Boise, ID
5
Reviseas'follows:
~ h e
fixture and hood shall be an approved assembly and so
'installed that the temperature limits of the materials used are
not exceeded.
SUBSTANTIATION: We are having problems where lights are listed
and labeled and are not properly installed as a complete
assembly. The hood and lights should be tested and approved to
meet Section 410-4 and Section 300-22(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 6, Section
410-4(c)(i).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
(
410-4(c)(1): Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
~
6
See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and replace with
"identified for use within commercial cooking hoods."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-Editorial(HoD 1978 NEC): Reject
CMP 21
SUBMITTER: A. KnicKrehm, Los Angeles, CA
2
AmendArticle 410 as follows:
Part K shall be moved to follow Part F.
Part N shall be moved to follow relocated K.
Parts Q and R shall be moved to follow relocated N.
Part G shall be relocated to follow relocated R.
Part H and J shall be relocated to follow relocated R~
All parts shall be reassigned letter designation.
SUBSTANTIATION: To arrange the article so that general and
Installation requirements precede construction requirements for
each of the s6bJects covered by the article. Article 410 does
not comply with the editorial style of the Code. The proposed
reorganization is in keeping with the editorial policy set forth
by the correlating committee.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 1A, Article 410.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-4(c) (5) (New): Reject
CMP 21
SUBMITTER: IdahoChapter IAEI Boise, ID
7
(5) Whenf i r e extinguishing equipment is
required, the energy supply to the appliance shall be
simultaneously interrupted upon actuation of the extinguishing
system.
SUBSTANTIATION: To coordinate with NFPA 17 4-4.1 the amended
addition will reduce f i r e hazards which would result from
overheated appliances when extinguishing chemical is expended.
PANEL RECOMMENDATION: Reject.
320
PANEL COMMENT: Proposal is not within the scope of Article
410. CMP 21conferred with CMP 10 and there was a lack of
support for the Proposal.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Wells.
EXPLANATION OF VOTE:
WELLS: I concur with the fact that thls proposal, is not
within the scope of ~ 21 and Article 410. I disagree with the
statement that there was a lack of support for the proposal from
Panel. For the record, I cite the comments of Panel 10 members
In their vote following the December, 1978 Panel meeting.
"Erickson:
In its present form the proposal cannot be
inserted in Article 422.' I believe the proposal has merit and
would like to see i t reworked for Article 422."
"Mazzoni: In my view Code Making Panel 21 was correct in
recognizing that the proposal did not belong in the referenced
section of the Code. On the other hand, I strongly feel that
thls proposal does not belong In Article 422 since i t is a
requirement that affects the appliances when installed in a
particular application. This is a very complex issue and in my
vlew should be thoroughly discussed at the April meeting before
being subject to a vote by CMP 10."
"Jordan: . . . . I would support a proposal that requires electric
fat fryers located under ventilating equipment protected by a
f i r e extinguishing system to be automatically de-energized upon
operation of f i r e extinguishing system."
The vote in December of CMP 10 was 1 affirmative, 3 negative
and, 5 not voting. I t appears to me there are many and varied
concerns about the wording but that the proposal does have some
support and I don't want to see i t lost between Panels.
410-8: Reject
CMP 21
SUBMITTER: Richard P. Kuchnicki, National Association of Home
B-GTI-a-~-(NAHB)
PROPOSAL: 11 Revise as follows:
~IIO-z~---.Fixtures in Clothes Closets.
(a) Location. A f i x t u r e in a clothes closet shall be
permitted to be installed: (1) on the wall above the closet
door, provided the clearance between the f i x t u r e and a storage
area where combustible'material may be stored within the closet
is not less than 18 inches or is protected in accordance with
Section 410-5 and (2) on the ceiling over an area which is
unobstructed to the floor maintaining an 18-inch clearance
horizontally between the f i x t u r e and a storage area where
combustible material may be stored' within the closet. I f the
f i x t u r e is protected in accordance with Section 410-5, the
18-inch clearance is not necessary.
A flushed recessed f i x t u r e equipped with a solid lens shall be
considered outside the closet area.
SUBSTANTIATION: The current Code requirement is in
contradiction with Section 410-5. I f a f i x t u r e is protected in
accordance with 410-5, the 18-inch clearance should not be
necessary. Many builders are forced to use recessed fixtures in
closets because i t is impossible to attain the 18-inch
clearance. Numerous fires have been reported due to recessed
fixtures coming in contact with improperly manufactured
cellulose insulation. Even though Section 410-66 regulates
insulation around recessed fixtures, i t is impossible to enforce
this regulation since insulation is added by the homeowner
usually without a building permit. Homeowners are not familiar
with the NEC.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 13, Section
4fO-8(a)(2).
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-4(d)-(New): Accept
~
CMP 21
SUBMITTER: Fred Mays, Albuquerque, NM
8
Add now (d) as follows:
--C-d~I~ixtures in Bathrooms.
(I) A f i x t u r e in a bathroom shall be on a c i r c u i t protected
by a ground-fault circuit-interrupter.
(2) Hanging fixtures and pendants shall not be permitted
directly above bathtubs, unless approved for damp or wet
locations, and shall be marked, "Suitable for Damp Locations."
SUBSTANTIATION: Article 410 is very careful in defining the
proper methods for installing fixtures in closets. The same
attention is required for fixtures in bathrooms. There is an
increasing trend toward the Installation of fixtures,
chandeliers, swag lamps and pendants over bathtubs, thereby
creating an extreme hazard.
• We cannot legitimately object to the installatlon of fixtures
over bathtubs, because i t is not specifically prohibited by
NEC. We cannot say that a bathroom is a wet or damp location.
PANEL RECOI~HENDATION: Accept as Revised:
(d) Pendants. Hanging fixtures and pendants shall be so
installed that the f i x t u r e is not 'less than 8 feet above the top
of the bathtub.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
C
410-8(a), Exception-(New): Reject
CMP 21
SUBMITTER: Ray H. Miller, Fond du Lac, WI
12 Add new exception as follows:
Exception: Fluorescent fixtures shall be permitted to be
installed on the wall above the closet door.
SUBSTANTIATION: Many new homeowners and builders wish to have
closet lights and with the restrictions of thermal insulation
near recessed fixtures, the Code makes i t almost impossible to
install recessed closet lights in second floor bedroom closets.
There would be no hazard involved i f the Code permitted a
two-foot fluorescent strip light above the closet door where the
surface temperature, of the tube is no danger and i t is in a
normally protected area.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 13, Section
410-8(a)(2).
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
410-8(a)(2): Accept
CMP 21
SUBMITTER: Clyde H. Craig, Toledo Chapter NECA
PlTOPO-SX
' t-~." 13 Changelast sentence of paragraph i2) to read:
~ s
enclosed surface f i x t u r e , r~cessed f i x t u r e with a
solid lens or fluorescent strip may be used providing there is a
6-inch clearance horizontally between the fixture and the
storage area.
SUBSTANTIATION: Most closets in homes are 24 inches deep,
making i t impossible to install anything but recessed fixtures.
Under today's insulation standards, i t ' s not practical to
install recessed fixtures in second floor closets. The 18 inch
requirement is too severe.
PANEL RECOMMENDATION: Accept as Revised:
Change the second paragraph as follows: A flush recessed
f i x t u r e with a solid lens, or a ceiling-mounted fluorescent
f i x t u r e shall be permitted to be installed provided there is a
6-inch clearance~ horizontally, between the fixture and the
storage area.
'
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-8: Reject
CMP 21
SUBMITTER: Allen KnicKrehm Los Angeles Chapter, NECA
PR~L:
g
Movethe material in Section 410-8 regarding
in clothes closets, to a new Section 210-27 t i t l e d :
"Lighting outlets permitted but not required."
SUBSTANTIATION: Article 210 new covers required outlets and
receptacles. Section 410-8 more clearly follows the scope of
Article 210 than Article 410.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not agree with the supporting
co~ent.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-8: Reject
,
CMP 21
SUBMITTER: S. B. Koontz, Chesapeake Chapter IAEI
~
10 Revise t i t l e as follows:
410-8. Incandescent Fixtures in Clothes Closets.
SUBSTANTIATION: The biggest f i r e hazard seems to be the surface
temperature of the incandescent bulb and hot particles of metal
falling onto clothes.
Since incandescent buIbs have a surface
temperature in the range of 500°F., and when broken will drop
hot particles, then i t would seem that only these fixtures
should be considered. By clarifying that i t is only
incandescent, i t would allow fluorescent fixtures to be used, as
they have always been classified as "cold" lighting, and can
even be touched after being on for long periods of time. This
would help some areas of the country where the main concern of
fixtures installed in closets is to provide lighting only and
not to provide any drying effect, as in some areas of the
country where incandescent fixtures are used.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 13, Section
410-8(a)(2).
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative."
410-11: Accept
~
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
151TOP-O-SA
' L~-~: 14 See the Technical Subcommittee "Recommendations"
under the definition ~f "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved f o r the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete "approved for the purpose" and replace with "identified
ifor through wiring."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-11, Exception-(New): Reject
CMP 21
SUBMITTER: Arnold W. Rodin, American Home Lighting I n s t i t u t e '
PROPOSAL: 15 Add the following exception:
~ i o n :
Branch circuit conductors having insulation
suitable for at least gO°C (194°F) shall be used for wiring of
321
all ceiling outlet boxes on which a lighting fixture is, or may
be, mounted. The ampacity of 90°C wire shall be limited to the
ampacity of 60°C wire (140°F).
SUBSTANTIATION: With the advent of energy conservation, thermal
insulation is being used more and more to combat winter heat
losses and summer heat gains in buildings. As a result, all new
construction, especially home construction, is being f i t t e d with
greater amountsof thermal insulation.
In most instances, electrical outlet boxes to which surface
ceiling incandescent fixtures are attached and junction boxes
supplying power to recessed fixtures are engulfed in a heavy
concentration of thermal insulation. This can lead to heat
buildup in the outlet boxes which may exceed safe values. These
higher temperatures are likely to destroy the insulation on
wiring in the boxes, resulting in shock hazard, short circuits
and f i r e . The condition may be further compounded when the
consumer chooses to ignore the fixture wattage marking and
installs higher wattage lamps.
In order to reduce the hazards that can be created by higher
temperatures in ceiling outlet boxes, we request that branch '
circuit conductors having insulation suitable for at least 90°C
(lg4°F) be used for wiring of all ceiling outlet boxes on which
a lighting fixture is, or may be, mounted. The ampacity limit
(15 amperes) for 60°C (140°F) conductors should be included to
retain the benefit of the higher temperature rating of gO°C
(Ig4°F) insulation.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ON PANELRECO~NDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
KNICKREHM: This proposal referred to CMP 6; CMP 6 rejected
the proposal.
410-14: Reject
CMP 21
SUBMITTER: D. H. Mclntosh, E. I. du Pont de Nomours & Co.
~ L :
16 Revise the second sentence as follows:
I t shall be permissible to locate cord-connected fixtures
directly below the outlet box i f (a) the flexible cord is Type
S, SO, ST or STO; (b) the cord is not subject to strain or
physical damage; and (c) the overall'length of
fixture-attached-cord does not exceed 6 feet.
SUBSTANTIATION: The word "suspend" cord-equipped fixtures
directly below the outlet box is a poor word choice implying
that the cord and outlet box support the weight of the fixture.
The words " i f the cord is continuously visible for its entire
length" has absolutely nothing to do with safety to either
persons or property, unless someonewants to devote their
lifetime to watching the cord. This section of Code has been
frequently massaged in past Code revisions. This is an earnest
attempt to resolve the issue.
UL has accepted and listed electric-discharge lighting fixture
connections for hung ceilings consisting of wiring in flexible
meta'l tubing terminating in an approved grounding plug (cap).
With over 1,500,000 fixture-years, of trouble free service, and
with fixture maintenance greatly enhanced by allowing the
fixture to be readily removable, i t seems reasonable to
recummendthis excellent system.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent. Panel feels subject is adequately covered. No
evidence to support the suggested change.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
WELLS~ The words " i f the cord is continuously visible for its
entire length" relates directly to safety. These words
effectlvely prohibit using a cord and plug to connect fixtures
in a lay in suspended ceiling where the ceiling panels would
render the cord invisible. Since these spaces above such
ceilings/are frequently air handling spaces i t is most
undesirable to have exposed plugs and receptacles which, over
time, would accumulate dust, grease and other potentially
hazardous contaminants.
SUBSTANTIATION: The Uniform Building Code requires that
suspended ceilings be adequately supported. This is usually in
the form of an iron wire support attached to the structural
ceiling members and the other end of the wire attached to the
suspended ceiling frame me~ers. The lighting fixtures are then
laid in the openings and secured only by light metal clips.
There have been numerous accidents occur when these metal clips
have been dis!odged causing fixtures to f a l l to the floor.
There have been several instances, where fixtures are installed
.in end-to-end rows, when one fixture becomes dislodged from
construction vibration causing the entire row to also f a l l to
the floor.
There is also the danger of fixtures being shaken loose by
seismic disturbances-Los Angeles, Oroville and Santa Rosa areas,
to mention a few~locations.
Having these fixtures attached to the framing members also
becomes a severe problem to firemen. When the ceiling area
becomes involved in a f i r e or enough heat generated from the
f i r e , the framing members distort and cause the fixtures to f a l l
through the openings.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMo
A agrees with the intent of the Proposal see
action on Proposal No. 17A, Section 410-16(b).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-16(b): Accept
CMP 21
SUBMITTER: CMP 21
17A Revise second sentence as follows: Fixtures so
shall be securely fastened by mechanical means, such
as bolts, screws, or rivots to the ceiling framing member.
SUBSTANTIATION: ~ 21 feels that f r i c t i o n alone is not an
adequate means for fastening, hence the use of bolts, screws, or
rivots.
PANEL RECOMMENDATION: Accept.
VOTEON PANELRECOMMENDATION:
AFFIRMATIVE: B.
NEGATIVE: Wells.
COMMENTON VOTE:
DUFFY: Although I am voting affirmative I believe there are
methods other than the rivets, bolts or screws that are
acceptable but can only be judged by the authority having
jurisdiction at the time of installation. I believe this should
be clarified.
KNICKREHM: The revised wording does not prohibit (he use of
clan~s secured by the mechanical means mentioned in the proposal
in my opinion.
EXPLANATION OF VOTE:
WELLS: Since there are listed clips for this purpose i t seems
to me they should be recognized. I suggest adding " . . . . screws,
Clips identified for the purpose, and rivets."
~
410-16(c): Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
P]TOP
' -O-~FA-C~- 18 See the Technical Subcummittee "Recommendations"
un-'n-dFe~-E~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
{c) RacewayFittings. Racewayf i t t i n g s used to support
l lighting fixtures shall be suitable to support the fixture(s).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
KIENER: I vote affirmative on this proposal; however, the
wording of the proposal could be in~)roved. I suggest the
following as an alternative:
"Raceway f i t t i n g s used to support light fixtures shall be
capable of supporting the total weight of the complete fixture
ass~ly."
i
410-18 (a): Reject
CMP 21
SUBMII-rER: G. A. Wintz Southern California IAEI
19 Add a second sentence as follows:
~ t
and swag type incandescent lighting fixtures having
exposed conductive parts and of types generally used in
dwellings shall be conspicuously marked "This fixture may be
unsafe where not properly connected to an outlet that is
equipped with a means for grounding."
SUBSTANTIATION: Pendant and swag type fixtures are being found
hung over bathtubs and the like. These fixtures are equipped
with bare or green grounding conductors and are tested and
listed for use when properly grounded.
However, millions of lighting outlets in existing dwellings
are not equipped with a means for grounding fixtures.
Furthermore the grounded circuit conductor is unidentified at
many existing lighting outlets supplied by knob and tube wiring.
Most replacement lighting flx~Jres for dwellings are sold,
hung and used by persons who are unaware of these serious
hazards attendant to the use of ungrounded or otherwise
impnoperly connected fixtures within reach o£ wet grounded
surfaces.
PANEL RECO~tENDATION: Reject.
410-14: Accept
CMP 21
SUBMITTER: CMP 21
: ~
16A In the~second sentence delete the word "suspend"
l~an--nd--~e-pTace with "locate."
SUBSTANTIATION: The word "locate" better reflects the intent of
the Panel.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-16(b}: Reject
CMP 21
SUBMII-TER: SouthwesternSection IAEI
17 Revise as follows:
- - ~ s p e n d e d Ceilings. Framing members of suspended ceiling
systems used to support fixtures shall be securely fastened to
each other and shall be securely attached to the building
structure at appropriate intervals. In addition, lighting
fixtures shall be independently supported at each end of each
fixture. The usual iron wire used for suspended ceiling
supports shall be permitted for this purpose.
322
PANEL COMMENT: CMP bases its rejection on Section 90-1(c)
"This Code is not intended as a design specification nor an
instruction manual for untrained persons."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Licursi.
EXPLANATION OF VOTE:
LICURSI: A negative vote was cast on the Panel Recommendation
because experience has proven that many pendant and chain-hung
fixtures are installed in bathrooms on branch circuits not
supplied with a grounding conductor.
I cannot conscientiously ignore the impact a warning label on
the fixture would have toward eliminating this very unsafe
practice.
410-18(a): Reject
CMP 21
SUBMITTER: International Association of Electrical Inspectors
20 Add a sentence to (a) as follows:
Pendant and swag type incandescent lighting fixtures having
exposed conductive parts and of types generally used in
dwellings shall be conspicuously marked "This f i x t u r e may be
unsafe where not properly connected to an outlet that is
equipped with a means for grounding," or words to that effect.
SUBSTANTIATION: Pendant and swag type fixtures are being found
hung over bathtubs and the like. These fixtures are equipped
with bare or green grounding conductors and are tested and
listed for use when properly grounded.
However, millions of lighting outlets in existing dwellings
are not equipped with a means for grounding fixtures.
Furthermore, the grounded circuit conductor is unidentified at
many existing lighting outlets supplied by knob and tube wiring.
Most replacement lighting fixtures for dwellings are sold,
hung and used by persons who are unaware of the serious hazards
attendent to the use of ungrounded or otherwise improperly
connected fixtures within reach of wet grounded surfaces.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP bases its rejection on Section go-1(c)
'iThis Code is not intended as a design specification nor an
instruction manual for untrained persons.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Licursi.
EXPLANATION OF VOTE:
LICURSI: See Comment on Proposal No. 19.
conductors will be subjected.
(FPN) For ampacity of fixture wire, see Table 402-5.
(FPN) For maximu~ operating temperature and voltage limitation
l of fixtures, wires, see Section 402-3.
SUBSTANTIATION: The words "environmental conditions" better
reflect the requirements of (b) and the overall proposal is in
agreement with the recoaraendations of the technical
subcommittee--Approved for the Purpose.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
410-41: Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
23 See the Technical Subcommittee "Recommendations"
un--6-d~-r--t-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
410_41. Insulating Joints. Insulating joints that are not
designed to be mounted with screws or bolts shall have an
exterior metal casing, insulated from both screw connections.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
r
410-42(a): Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
I~TO]~-S'A-C~ 24 See the Technical Subcommittee "RecommendationsZ'
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
(a) General. Portable lamps shall be wired with flexible cord
recognized by Section 400-4 and an attachment plug of the
polarized or grounding type.
Delete the exception.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
410-42(b)(2):
Accept
CMP 21
SUBMITTER: TSC-Approvedfo~ the Purpose
~ 2 5
See the Technical Subcommittee "Recommendations"
under the definition of MApproved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
(2) Handlamps shall be equipped.with a handle of molded
composition or other insulating material.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
COMMENTON VOTE:
KIENER: I vote affirmative, but recommend the following
change in wording:
"Handlamps shall be equipped with a handle of molded
composition or other insulating mater,ial capable of withstanding
the voltages involved."
410-20(New): Accept
CMP 21
SUBMITTER: Allen KnicKrehm, Los Angeles, CA
21 Add section as follows:
Equipment Grounding Conductor Attachment. Fixtures
with exposed metal parts shall be provided with a means for
connecting an equipment grounding conductor for such fixtures.
SUBSTANTIATION: Wiring methods providing equipment ground
conductors as a grounding means, such as nonmetallic raceway
syste~1~ and nonmetallic cable systems, must have a method
whereby the equipment ground connector can be connected to the
exposed metal parts of the lighting fixtures.
I t has been brought to the writer's attention that d r i l l i n g a
hole or fastening a grounding conductor to a listed or labeled
f i x t u r e may void the listing of the f i x t u r e . Therefore i t is
f e l t necessary for the Code to provide a means for connecting
the equipment grounding conductor to the fixture to assure
compliance with the provisions of the Code.
PANEL RECOMMENDATION: Accept.
VOTEON PANEL RECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Short.
EXPLANATION OF VOTE:
SHORT: the proposal would require a method of attaching a
grounding conductor on all fixtures. This is unnecessary, when
the fixture is connected with conduit.
410-49: Reject
CMP 21
SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter IAEI
26 Revise to read:
Lampholders.
(a) Lampholders installed in wet or damp locations shall be
of the weather-proof type.
(b) Porcelain or metal shell sockets used as cord pendant
lighting outlets shall not be permitted within reach of grounded
portion of buildings.
SUBSTANTIATION: Where such fixtures are used in areas
containing high humidity, such as basements, they tend to
collect moisture and become a shock hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not Justify the
proposed change. Supporting comment is not persuasive as to
necessity.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
COMMENTON VOTE:
WELLS: There is no definition or product category called
"weather-proof" and to accept this proposal without such would
be meaningless. There are "wet location" and "damp location"
definitions and in view of the Panel's action on Proposal 4A the
problems referred to in the substantiation supported the (b)
portion of the proposal.
410-24(b): Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
I~R-O-P-O-S~At-~
". 22 See the Technical Subcommittee "Recnmmendations"
un--~-d-e~-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept.
IPANEL COMMENT: See CMP Proposal No. 22A.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-24: Accept
CMP 21
SUBMITTER: CMP 21
PROPOSAL: 22A Add the words "environmental conditions" after
~ s
"suitable for the." Delete (b), and'(a) becomes text
of 410-24. Fine print notes remain. To read as follows:
410-24. Conductor Insulation. Fixtures shall be wired with
conductors having insulation suitable for the environmental
conditions, current, voltage, and temperature to which the
I
t
410-52: Accept
CMP 21
SUBMITTER: Clyde H. Craig, Toledo Chapter NECA
Is-R-O-fs~-~L-~•. 27 Add additional sentence as follows:
~ord
shall be nonflammable or chain shall extend a
minimum of 10 inches frnm lamp holder.
SUBSTANTIATION: There have been cases of large wattage lamps
burning pull cord and causing smoldering cord to f a l l to fIoor
323
where flammable material may be present.
PANEL RECOMMENDATION: Accept as Revised:
J Pull cord shall be nonflammable, or chain portion shall extend
a minimum of 7 inches from the lampholder.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Short.
EXPLANATION OF VOTE:
SHORT: There is no evidence of a problem. Not a single case
has been reported to the concerned manufacturers involving
accidents of this type.
410-56(a)-(New): Reject
CMP 21
SUBMITTER: R. C. Cressman, General Electric Co.
2B Add new (a) and existing (a) becomes (b), etc.
- - - ~ e p t a c l e s , cord connectors, and attachment plugs rated 15
and 20 amperes and intended for use with connection to portable
cords shall be approved for the use intended (not.hard usage,
hard usage, extra hard usage).
SUBSTANTIATION: The Code presently recognizes in Table 400-4
three types of usages for portable cords (not hard usage, hard
usage, extra hard usage). The devices intended for use with
these cords should be similarly recognized. The attachment
plug, connector and receptacle receive abuse similar to that of
cords. Plugs and connectors are subject to the same crushing
forces as portable cords. Plugs, connectors, and receptacles
can be damaged by abrupt removals, even more so than the cord.
The requirements 6or a receptacle, cord connector, and
attachment plug for use in the home on AWG18 SPT are quite
different from those used in heavy industry on AWG18 SO.
Definitions of use difference have been made by NEMA(WD1-1974,
Part 3-General Duty and Heavy Duty), the Federal Government
(WC5996-E), the International Electrotechnical Commission
(Household Use and Industrial Use), and by UL 498 (Regular and
Hospital Grade). The recognition by the Code of two usage
differences would give guidance to UL to develop requirements to
meet the needs of the user as they have done in flexible cords.
I t would also serve as a basis for a single standard eliminating
the duplication now being done by the various agencies.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
receptacle.
SUBSTANTIATION: TIA to the 1978 NEC.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-S6(f)-(New): Reject
CMP 21
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
32 Addnew i f ) as follows:
---(-~'--(~perating at Over 300 Volts. Attachment plugs or other
connectors supplying equipment at over 300 volts shall be of the
skirted type or otherwise designed that arcs will be confined
within the case of the plug or receptacle.
SUBSTANTIATION: The users of electrical equipment have been
severely injured when they attempted to plug in or connect a
piece of faulty equipment to a circuit operating at over 300
volts. At this higher voltage a fault will produce severe
arcing and violent discharge of molten metal which requires a
skirted type of receptacle to provide workman safety.
,,
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity. Existing devices, rated in excess of 300 volts, are
tested at 150 percent of rated current at rated voltage. In
addition, the Chairman has appointed a Task Force, chaired by
Walter Short, to obtain further information for consideration
for the next Code cycle.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
/
410-56(f)-(Newi: Reject
CMP 21
SUBMITTER: SouthwesternSection IAEI
33 Add subsection i f ) to 410-56 to read:
~perating
At Over 300 Volts. Attachment plugs or other
connectors supplying equipment at over 300 volts shall be of the
skirted type or otherwise designed that arcs will be confined
within the case of the plug or receptacle.
SUBSTANTIATION: The users of electrical equipment have been
severely injured when they attempted to plug In or connect a
piece of faulty equipment to a circuit operating at over 300
volts. At this higher voltage a fault will produce severe
arcing and violent discharge of molten metal which requires a
skirted type of receptacle to provide workman safety.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 32, Section
410-56(f).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-56(b), Exception-(New): Reject
CMP 21
SUBMITTER: Ted Steppe, Stepp-Elex Corp.
29 Add a new exception as follows:
x-'~lon:
A metallic faceplate of ferrous metals which is
stamped in one piece and having a recessed center section of
sufficient area to effectively seal a standard device box shall
have a thickness not less than 0.020 inch.
SUBSTANTIATION: A faceplate with a recessed center is by far
many times more rigid than any f l a t faceplate. We therefore
feel that the thickness of the metal can be reduced from 0.030
to 0.020 inches without giving up a large amount of strength,
because of the internal bends in the center of the faceplate.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not agree with the supporting
comment.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
410-56(c): Accept
CMP 21
SUBMITTER: E. E. Carlton, Menlo Park CA
30 Revise the second sentence as follows:
~ates
shall be installed so as to completely cover the
wall opening and seat against the wall surface.
SUBSTANTIATION: To provide safety and prevent access to exposed
live metal parts. This islan accepted practice and should be
added to the Code. The same requirement presently is included
in Section 380-9 for switches. Addition of this proposal to
410-56(c) will provide safety for receptacle outlet
installations also.
PANEL RECOMMENDATION: Accept as Revised:
Delete the word "wall" before the word "opening." Delete the
word "wall" before the word "surface" and replace wlth
"mounting." To read as follows:
Faceplates shall be installed so as to completely cover the
opening and seat against the mounting surface.
PANEL COMMENT: C~ 21 feels that there are times when covers
are required to seat against surfaces other than "walls" such as
gaskets or surface-mounted boxes.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-56(g)-(New): Accept
CMP 21
SUBMITTER: CMP 2
II~-O]~O~A
' -L-~
•. 29 (CMP2) Revise as follows:
-~{-~(~onductors. Receptacles rated 20 amperes or less
directly connected to aluminum conductors shall be marked CO/ALR.
SUBSTANTIATION: I t was the action of the Correlating Committee
to advise CMP 2 that the Correlating Committee has referred
Proposal No. 29 to CMP 21 for action.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: ThF'text of Section 210-7(g) (see Proposal No.
29-CMP 2) has been revised and relocated to new Section
410-56(g) as per action of the Correlating Co~nittee.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-57(b), Exception: Reject
CMP 21
SUBMITTER: O. E. Oillon, Border County Div. IAEI
)~rOl~O~'At-~.34 Delete exception.
~OI~S~F~J~rIATION: This section is legally unenforceable due to
the use of the words "not likely" and "not usually." At the
time of inspection, the inspector cannot determine the future
use of the receptacle. See the attached opinion* of the San
Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ I Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL CO~MENT: CM@'-agreeswith the intent of the Proposal see
action on Proposal No. 34A, Section 410-57(b).
VOTE ON PANE~RECOMMENDATION: UnanimouslyAffirmative.
CMP 21
410-57(b), Exception: Accept
SUBMITTER: C~ 21
II)~IOP~)-S'-A-L-~: 34A Delete the words "likely" and "usually."
~'I)~rS'~'~N~rIATION: The words "likely" and "usually" are not
definitive of the requirement.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-56(e)(TIA 1978 NEC): Accept
CMP 21
SUBMITTER: TIA 2-70-1978
31 Add a new Section 410-56(e) and change present
~ h
(e) to (f).
{el Attachment Plug Ejector Mechanisms. Attachment plug
ejector mechanisms shall not adversely affect engagement of the
blades of the attachment plug with the contacts of the
324
410-57(b), Exception: Reject
CMP 21
SUBMITTER: R. C. Medley, Square D Co.
]~II)POS'XL-~..35 Delete the words "self-closing."
~'I]I~'rAI~FIATION: The reason for the request to remove
"self-cl6sing" results from the interpretation by UL based upon
these words that any cover which required user assistance wlll
no longer be acceptable for such usage effective January I ,
1979, as covered by UL S14-C dated November 3, 1977, Paragraph
10.6. I t states: UA cover with a detent or other feature
designed to hold i t open Is not to be assisted in closing."
Unfortunately, the UL interpretation prohibits" a feature which
is of importance to the users of cover plates. Such p)ates are
typlcally used for switches as well as temporarily connected
receptacles. A hold-open feature permits the user to open the
lid an.d then insert or remove a plug (or operate a switch)
a11owing one hand operation. I t also permits one hand closure
with equal ease.
Such covers have been successfully used for over 15 years
without incident. A hold-open feature is also of necessity to
the milllons of a r t h r i t i c a l l y affected consumers, as well as
others of physical incapacity who use these covers on their
homes.
The removal of the term "self-closlng" will allow the use of
weatherproof covers marked "Wet Location with Covers Closed"
which will otherwise satisfy UL requirements.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
410-58(b)(4): Reject
OMP 21
SUBMITTER: F. K. Kltzantides, NEMA
I~R-O-PO-S'A~-~..38 Revise as follows:
"(-4")-- I f the terminal for the equipment grounding conductor
is not visible, or i f terminal screw is removable, the conductor
entrance hole or the area adjacent to the terminal shall be
marked with the word "green" or the symbol " ~--~-_" or otherwise
identified by a distinctive green c o l o r .
SUBSTANTIATION: The ground symbol " ~ "
is an international
means of Identifying ground. I t is used in electric drawings
and schematic diagrams. A symbol is used to transmit a message
in a clear understandable manner independent of any language.
PANEL RECOMMENDATION: Reject.
PANEL COI~4ENT: The proposal to use a ground symbol to identify
a groundlng terminal would not, in the CMP's opinion, further
the cause of electrical safety. The proposal to use a grounding
symbol in lieu of the present green identification as required
by the '78 NEC is unacceptable since i t would increase the
probability of miswiring of the device.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Knickrehm.
COMMENTON VOTE:
WELLS: The grounding symbol is unknown to millions of
consumers who wire devices. Coloring the terminal provides
color identification with the green wire. Using a technical
symbol on a product which can be wired by a broad spectrum of
non technical users is, in my opinion, wrong.
EXPLANATION OF VOTE:
KNICKREHM: This use of graphics to overcome language and
color barriers is internationally accepted. The NEC should also
accept this fact.
-
Pane I ' s l n t e n t .
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
WELLS: In my opinion, i t is the specific intent of the
present wording to prohibit what the submitter wants to permit.
While I t may be convenient for one-handed operation to have a
cover stay open, I t is also convenient for a user to f a i l to
close the cover thus defeating the very purpose of the cover in
the f i r s t place. Further, covers with hold-open features expose
the open covers to physical abuse which may prevent their future
effective use.
410-68(a)(HOD 1978 NEC): Reject
CMP 21
SUBMITTER: John M. Wall, Central Calif. Chapter, Fresno, CA
!~TOPI~S'~-~.'36 AmendSection 410-SB(a) to read:
~ounding
type receptacles, cord connectors and
attachment plugs shall be provided with one fixed grounding pole
in addition to the circuit poles "and shall be polarized when of
the 2 parallel slot and blade configuration."
SUBSTANTIATION: There is a built-in safety feature in the
grounding type receptacles in the form of a wider slot and
associated terminal for the grounded circuit conductor and a
narrower slot for the phase or hot circuit conductor and
termination of the parallel slot 16 ampere 125 volt
configuration. This feature provides safety whereby a 2 wire
parallel polarized blade attachment plug and identified
conductors and appliances may be used with a better degree of
safety.
PANEL RECOMMENDATION: Reject.
PANEL COMI~ENT: No significant contribution to safety would
result.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Licursi.
CO~IENT ON VOTE:
WELLS: the present wording in 410-42 will require polarized
plugs on portable lamps January I , 1980. Nothing in the
substantiation Justifies requiring polarized plugs on two wire
clocks, appliances, double insulated tools, etc.
EXPLANATION OF VOTE:
LICURSI: A negative vote was cast on the Panel Recommendation
because with the requirement of 410-42(a) becoming effective
January 1, 1980, there is no requirement in the Code that will
provide a polarized receptacle for a two-wire polarized portable
lamp.
410-58(c): Accept
CMP 21
SUBMITTER: Nathaniel J. Addleman, Wichita, KS
PROPOSAL: 39 Add a sentence as follows: Grounding type
~ n t
plugs shall not be installed without a proper ground
connection being made between the appliance and the grounding
terminal of the plug.
SUBSTANTIATION: At present there seems to be no explicit
prohibition against installing a grounding type attachment plug
on an electrical cord w~thout a grounding conductor. Such an
installation could lead to the erroneous conclusion that the
appliance that has a "two wire cord" connected to a "three prong
plug" is grounded, since the wire connections on the backside to
the plug are usually hidden from view, and since i t has become
common knowledge that a "three pron9 plug" means that the
appliance to which i t is connected {via the power cord) is
grounded.
Section 410-58(c) is not explicit enough to prohibit the above
misleading use of a grounding type attachment plug.
PANEL RECO~FF4ENDATION: Accept as Revised:
I Add a new {e] to 410-58 as follows:
(e) Use. Grounding-type attachment plugs shall be used only
where an equipment ground is to be provided.
VOTEON PANELRECOMMENDATION:' Unanimously Affirmative.
Article 410, Part M: Reject
CMP'21
SUBMITTER: Warren Anderson, Mount Vernon, WA
!°ITOPl~'~B~-~.'40 Delete410 Part M. Rosettes
~]I~'AI~FIATION: The need to cover rosettes in the 1981 Code has
disappeared with the dinosaur.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirement is necessary.
VOTEON PANELRECOMMENDATION: Unanimously Affirmative.
410-64: Accept
CMP 21
SUBMII'TER: TSC-Approvedfor the Purpose
~ 4 1
See the Technical Subcommittee "Recommendations"
un--n-d-e-r-t~Te definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "of a type approved for the purpose and
shall" and replace with l 'identified for such installation.'i
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-58(a), Exception: Reject
CMP 21
Secretary's Note: I t was the action of the Correlating
Committee that correlation may be necessary with Proposal
Nos. 50 and 52 of Code-Making Panel 5.
SUBMITTER: John L. Bennett, Power Tool Institute
37 Delete the exception.
~I]B-~'~]~IATION: Thi~ Exception anticipates the connection of a
~oo1 or appliance to either a receptacle with a grounding pole
or to a two pole receptacle without a grounding pole. The
availability of grounded receptacles has increased to the point
that there is very l i t t l e advantage in the use of plugs with
movable grounding poles. The installation of grounded
receptacles or fixed adapters should be encouraged. There is no
apparent need to condone the ungrounded use of a tool or
appliance which is normally required to be grounded.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
~ecesslty.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-64(a)-(New): Accept
CMP 21
SUBMITTER: R. E. Ward, Tenn. Chapter, IAEI
I~TOTrO~K[~-.'42 Add new (a) as follows:
- - - ~ e c e s s e d or surface mounted incandescent fixtures'
installed indoors adjacent or on co(nbustible materials shall
have thermal protection integral with the lampholders.
Exception: Fixtures with miniature intermediate l ampholders.
SUBSTANTIATION: Fires are being caused under present Code rules
usually due to over-lamping or misuse of insulating materials.
This proposal, i f enacted, will give protection from this type
hazard.
325
410-66: Reject
CMP" 21
SUBMITTER: Ronald C. Zaker, Halo Lighting
I~q~O-S'A-L-T.'46
Add new sentence as follows: Thermal insulation
~ d
in ceilings that contain recessed fixtures, shall be
inspected, including r e t r o f i t installations.
SUBSTANTIATION: Thermal insulation is being added to ceilings
after recessed fixture installations have been inspected. This
normally occurs at the termination of the building construction
or at a later date after the building is occupied as a r e t r o f i t
installation. In order to assure compliance with Section
410-66, both installation types should be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
PANEL RECOMMENDATION: Accept as Revised:
Where recessed or surface-mounted incandescent fixtures are
installed indoors, the lampholders shall have thermal protection
integral within the l ampholder or otherwise thermally protected
and identified for such conditions of use. Replacements for
these l ampholders shall also be integrally protected.
Exception No. 1: Fixtures with minature l ampholders.
Exception No. 2: This requirement shall become effective
January 1, 1982.
PANEL COMMENT: CMP 21 has accepted the revised text and
indicated the material be relocated to proposed Section 410-40
as per CMP 21 Proposal 1A.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 7.
NEGATIVE: Duffy, Short.
,COMMENTON VOTE:
WELLS: I vote affirmatively because I believe the magnitude
of the problem, in part demonstrated by the many proposals from
manufacturers and distributors of such fixtures, mandates
action. Subsequent to the Panel Meeting, I have been informed
of a patent which might directly affect "integral protection of
l ampholders" and I believe the Panel, in its next meeting must
revise the wording so as to allow other equally effective means
of protection.
EXPLANATION OF VOTE:
DUFFY: I am voting negative on the proposal because i t
includes surface mounted units. Surface mounted incandescent
fixtures labeled by Underwriters Laboratories since August of
1978 have been tested and found acceptable for use on insulated
ceilings. These fixtures are identified by the letters IC
(Insulated Ceiling). Also I believe the technical complexity of
having the thermal protection integral with the lampholder is
impractical. I would support the proposal with the deletion of
"or surface mounted" and I believe the requirement for integral
l ampholder thermal protection and replacement of such
lampholders should be deleted.
SHORT: The proposal should be altered to call for the fixture
i t s e l f to have thermal protection rather than singling out the
lampholder within the f i x t u r e . This would permit UL, in their
examination listing, to determine the hottest point of the
fixture under an abnormal temperature test and that the thermal
protection within the fixture would be such as to control the
maximum temperature of that particular point of the fixture.
410-66: Reject
CMP 21
SUBMITTER: R. A. Wiedemer, Jr., Hinkle Lighting
PROPOSAL: 47 Add new sentence as follows: Retrofit thermal
l-n-sula-L~Fon installed in ceilings tha~ contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-66: Reject
CMP 21
SUBMITTER: Harold S. Minoff, L. D. Kichler Co.
PROPOSAL: 48 Add a new sentence as follows: Retrofit thermal
~ o n
installed in ceilings that contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ce111ngs after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
/
410-66: Reject
CMP 21
SUBMITTER: Murray Feiss, American Home Lighting Institute
I~RI)]~S'AlZ~.'43 Add new sentence as follows: Retrofit thermal
l-6-s-~laTTon installed in ceilings that contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure cempliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL CO~V4ENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-66: Reject
CMP 21
SUBMITTER: Arnold W. Rodin, American Home Lighting Institute
!~R'(I!~'AL-~.• 44 Add new sentence as follows: Retrofit thermal
l-6s'~-l-~-t-Ton installed in ceilings that contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
Is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-66: Reject
CMP 21
SUBMII-FER: Marvin Leichtung, Puritan Lighting Fixture Co.
PROPOSAL: 49 Add a new sentence as follows: Retrofit thermal
' ~ o n
installed in ceilings that contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: In many instances, thermal insulation is added
to ce111ngs after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-66: Reject
CMP 21
SUBMITTER: Marc A. Katz, Fredrick Ramond, Inc.
PROPOSAL: 50 Add a new sentence as follows: Retrofit thermal
~ o n
installed in ceilings that contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ce~I1ngs after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL ~OMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION:. Unanimously Affirmative.
410-66: Reject
CMP 21
SUBMITTER: Harry W. Rothenberg, Timely Lighting
45 Add new sentence as follows: Retrofit thermal
Insu~-6-s-~l~-t-fon installed in ceilings that contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: The push for energy savings has resulted in
thermal insulation being added after recessed fixtures have been
installed and inspected, in too many cases, years after
installation of recessed fixtures. The reference to r e t r o f l t
installation is as indicated above. To assure co~oliance with
Section 410-66, the thermal installation should be inspected.
The lack of such a requirement to inspect creates a potential
f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-66: Reject
CMP 21
SUBMITTER: A. Ebenstein, American Home Lighting Institute
I~TOI~S'XL-~.'51 Add a new sentence as follows: Retrofit thermal
insulation installed in ceilings that contain recessed fixtures,
shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
326
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOIC~ENDATION: Reject.
PANEL COI~ENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-66: Reject
C~ 21
SUBMITTER: Reynolds K. Ohal, Santa Fe Springs, CA
~ 5 7
The following additional sentence should be added
to Section 410-66.
Retrofit thermal insulation installed in ceilings that contain
recessed fixtures shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected. The absence of the require~nts for such
inspection constitutes a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COVa4ENT: See Panel action onProposal No. 42.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-66: Reject
CMP 21
SUBMITTER: ai~ Wiederhold, Corbett Lighting, Inc.
52 Add new sentence as follows:
~ i t
thermal insulation installed in ceilings that contain
recessed fixtures, shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative~
410-66: Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
PITOP-O-SA
' I_-~: 58 See the Technical Subcommittee "Recommendations"
under the def!nition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose" and replace with
]"Identified f o r installation within thermal insulation."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-66: Reject
CMP 21
SUBMITTER: Sidney Wolkin, Lightolier, Inc.
53 Add a sentence as follows:
Retrofit thermal insulation installed in ceilings that contain
recessed fixtures, shall be inspected to assure that no
insulation is within 3 inches nor on top of fixture.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
410-66: Reject
CMP 21
SUBMITTER: Irwin Goldberg, Coronet Chandelier Originals
PROPOSAL: 54 Add a sentence as follows:
~ I t
thermal insulation installed in ceilings that contain
recessed fixtures, shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to cei|ings after recessed fixtures have been inspected. This
is normally referred to as r e t r o f i t installation. In order to
assure cempliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential f i r e hazard.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECO~V~IENDATION: Unanimously Affirmative.
410-66: Reject
CMP 21
SUBMIl-rER: O. E. Dillon, Border County Div. IAEI
~ O S A L : 55 Revise second sentence as follows:
~ e d
fixture enclosures, wiring compartments or ballasts
shall not be installed within" three inches of thermal insulation
or in such a location so that heat is entrapped and free
circulation of air is prevented except when the f i x t u r e is
listed for the use.
SUBSTANTIATION: This section is practicably unenforceable as
Che electrical inspector does not inspect or control the
installation of thermal insulation. The use of the words
"combustible material" without a definition of combustible
material renders this section legally unenforceable. See the
attached opinion* of.the San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for"
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 42.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
410-66: Reject
CMP 21
SUBMITTER: Julian Chacon, Lightcraft of California
56 Add new sentence as follows:
Retrofit thermal insulation installed in ceilings that contain
recessed fixtures, shall be inspected.
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with 410-66, the installation should be
inspected.
410-66: Reject
CMP 21
SUBMITTER: Frederick W. Van Cott, Sea Gull Lighting Products~
PROPOSAL: 59 Add the following sentence:
~ i t
thermal insulation installed in ceilings that contain
recessed fixtures, shall be inspected,
SUBSTANTIATION: In many instances thermal insulation is added
to ceilings after recessed fixtures have been inspected. This
is normally referred to as a r e t r o f i t installation. In order to
assure compliance with Section 410-66, the installation should
be inspected.
The absence of the requirement for such inspection constitutes
a potential ~ire hazard.
PANEL RECOf~4ENDATION: Reject.
PANEL COVd~ENT: See Panel action on Proposal No. 42.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
410-66: Reject
CMP 21
SUBMITTER: K. V. Jester, Texas Chapter/IAEI
P R O P ~ 60 Revise as follows:
Recessed portions of enclosureS, other .than points of
support, shall be sp~ced at least 1/2 inch from combustible
material andsuch fixtures shall incorporate thermal protection
when located in an area where thermal insulatiun will be
installed.
Fixtures which are so designed or installed to physically
prevent thermal insulation from being installed within three
inches of the ~ecessed f i x t u r e enclosure, wiring compartment or
ballast are not required to be thermally protected.
SUBSTANTIATION: For several years the Code has attempted to
deal with the problem of thermal insulation surrounding recessed
lighting fixtures without a great deal of success. This is a
growing problem due to the energy conservation efforts where
more and more insulation is being installed, especially in
homes. The present requirements in the Code of thermal
insulation not being installed within three inches of recessed
fixtures is practically unenforceable by electrical inspectors.
When the fixtures are installed and inspected they co~iply with
the Code but only until the insulation installers come on the
job. This problem is real and needs to be corrected by the
electrical industry and not by placing requirements on people
(insulation installers) over whom we have l i t t l e control. The
requirement for thermal protection for the fixtures themselves
is not the complete solution to the problem but should relieve a
situatiq~ which can only beceme worse with time. Therefore, the
exception needs to be included to permit the installation of
fixtures without thermal protection where other safeguards are
provided or where in some cases thermal insulation will not be
installed.
PANEL RECOMMENDATION: Reject.
• PANELCOMMENT: See Panel action on Proposal Nos. 42 and 63A.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
327
410-72: Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
61 See the Technical Subcommittee "Recemmendations"
~ e r the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the'purpose" and replace with
or other suitable insulating materials."
VOTE ON'PANEL RECOMMENDATION: UnanimouslyAffirmative.
410-80 (b): Accept
CMP 21"
SUBMITTER: TSC-Nominal Voltage
J ~
65 Change"supply" to " c i r c u i t . "
~'~)I~7"~NI"IATION: For the sake of uniformity in terminology
consistent with recommendations being made by the TSC for usage
throughout the Code.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
"Article 410 Part S-(New): Accept
CMP 21
SUBMITTER: Stephen D. Channer, Business and Institutional
Manufacturer's Assn. BIFMA
PROPOSAL: 66 Add Part S at the end of Article 410 as follows:
S. Special Provisions for Office Furnishings
410-100. General. Wiring systems shall be listed and approved
for the purpose of providing power for lighting and office
appliances to office furnishings.
410-101. Other Articles. All articles of the Code shall apply
where applicable.
410-102. Flexible Cords and Cables.
(a) Office furnishings shall be permitted to be connected by
flexible cords or cables to outlets approved for the purpose.
(b) Flexible cords and cables shall be permitted for the
wiring within office furnishings approved for the purpose.
SUBSTANTIATION: Thls proposal concerns i t s e l f with wiring
systems as provided by members of our industry with office
furniture'systems that are now being used extensively in offices
throughout the United States. Although not exclusively, office
furniture systems are primarily used In areas referred to as
"open plan" or "landscape" office layouts.
Within our industry, office systems furniture has grown in
popularity to a great extent over the past several years. Much
of the popularity stems from the advantages of portability and
ease of rearrangement. Today the sales of this type of
furniture are well over $300 million dollars annually and
growing. Due to energy conservation requirements users have
demanded the inclusion of task and ambient lighting with this
type of furniture. Current industry estimates show that
approximately 80 percent of all office furniture systems sold
contain electrical power. Whensuch power is provided by
manufacturers within our association, safety is foremost in
their consideration and all wiring systems have been or are in
the process of being submitted to and listed by Underwriters
Laboratories or other nationally recognized testing laboratories.
Our industry is very proud of its concern for product safety
and performance and the good record that i t currently enjoys.
Our purpose in submitting the enclosed proposal to the National
Fire Protection Association is to establish a category within
the National Electrical Code that deals specifically with
products made within our industry that contain wiring systems
and to provide in writing the standard of quality that must be
adhered to by those making such systems.
Your review and favorable consideration of this proposal will
be very much appreciated by the business and institutional
furniture industry.
PANEL RECOMMENDATION: Accept as Revised.
410-73(b): Accept
CMP 21
SUBMITTER: TSC-Nominal Voltage
J~ROPOSAL: 62 Change"supply" to "circuit."
SUBSTANTIATION: For the sake of uniformity in terminology
consistent with recommendations being made by the TSC for usage
throughdut the Code.
PANEL RECOM~IENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-73(e), Exception: Reject
CMP 21
SUBMITTER: O. E. Dillon, Border County Div. IAEI
~ 6 3
In the Exception to (e), add the phrase " i . e . ,
does not employ capacitors" to the end of the sentence.
SUBSTANTIATION: The exception renders this section legally
unenforceable as there is no definition of a simple reactance
ballasts. See the attached opinion* of the San Diego City
Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. 90 for 110-16(a).
I
PANEL RECOMMENDATION: Reject.
PANEL COr~4ENT: The present wording adequately reflects t h e
Panel's intent. The Panel does not agree with the supporting
comment.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
410-73(f)-(New): Accept
CMP 21
• SUBMITTER: CMP 21
PROPOSAL: 63A Add (f) as follows:
~ e r e
recessed high-intensity discharge fixtures with
integral ballast are installed indoors, the ballasts shall have
thermal protection integral within the ballast. Replacements
for these ballasts shall also be integrally protected.
Exception: This requirement shall become effective January 1,
1982.
SUBSTANTIATION: CMP 21 extends the same protection to provide
for recessed high-intensity discharge fixtures that is now
applied to fluorescent fixtures.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Short.
COMMENTON VOTE:
DUFFY: Although I am voting affirmative I believe further
consideraton of the effective date may be necessary to allow
time for development and implementation of the,protection
program.
WELLS: See Comment on Proposal No. 42.
EXPLANATION OF VOTE:
SHORT: This requirement is unnecessary because HID ballasts
f a i l in a low resistance mode which results in blowing of fuses
or tripping of circuit breakers whereas fluorescent ballasts
f a i l in a high resistance mode.
S.
SPECIALPROVISIONSFOR LIGHTINGACCESSORIES
AND WIRED PARTITIONS
410-100. General. Wiring systems shall be identified as
suitable for providing power for lighting accessories and
appliances in wired partitions. These partitions shall not
extend from the floor to ceiling or exceed 7 feet in height.
410-103. Other Articles. Wherever the requirements of other
articles of this Code ~nd Part S of Article 410 d i f f e r , the
requirements of Part S, Article 410 shall apply.
410-106. Wireways. All conductors and connections shall be
contained within wiring channels of metal or other material
identified as suitable for the conditions of use. Wiring
channels shall be free of projection or other conditions that
may damageconductor insulation.
410-75(b): Reject
CMP 23
SUBMITTER: NormanB. Cooney, Parma, OH
64 Revise Section 410-75(b) as follows:
~ n t
exceeding 300V may be installed in dwelling
occupancies i f the design prevents exposed live parts.
SUBSTANTIATION: These sections are so confusing I don't believe
an explanation is possible. Yo~ can, you can't, you can. Which
is it? Can you or can't you?
I would think somewhere In this morass of perplexibility that
someone would correlate the different CMP's and come up with a
viable solution to this absurdity.
How can someone be expected to intelligently enforce
provisions of theNEC when they are written in thls fashion?
Simplicity in articles and words should be the byword of the
NEC, not the confusion that is usually expressed.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANEL,RECOMMENDATION: UnanimouslyAffirmative.
(FPN) Conductors as used in this section do not include
flexible cord.
410-108. Partition Interconnections. The electrical connection
:between partitions shall be a flexible assembly marked for use
with wired partitions.
Exception: Flexible cord shall be permitted for the
connection between partitions provided all of the following
conditions are met.
' a. The cord is extra-hard usage type.
b. The partitions are mechanically contiguous.
c. The cord is not longer than necessar~ fo~ maximum
positioning of the partitions but, in no case to exceed 2 feet.
d. The cord is terminated at an attachment plug and cord
connector with strain relief.
410-110. Lighting Accessories. Lighting equipment marked for
use with wired partitions shall comply with all of the following:
(a) Support. A means for secure attachment or support shall
be provided.
(b) Connection. Where cord and plug connection is provided,
328
the cord length shall not exceed 8 feet~
(c) Receptacle Outlet. Conveniencereceptacles shall not be
)ermitted in lighting accessories.
EXPLANATION OF VOTE:
DUFFY: I am no~ voting on this proposal as such action may be
interpreted as self-serving.
%10-112. Fixed Type. Wired partitions that are fixed (.secured
to building surfaces) shall be permanently connected to the
building electrical system by one of the wiring methods of
Chapter 3.
410-115. Free-Standing Type. Partitions of the free-standing
type (not fixed) shall be permitted to be permanently connected
to the building electrical system by one of th~ wiring methods
of Chapter 3.
Individual partitions of the free-standing type, or groups of
not more than six individual partitions which are mechanically
contiguous, shall be permitted to be connected to the building
electrical system by a single flexible cord and plug provided
all of the following conditions are met.
(a) Cord Type. The flexible power-supply cord shall be
extra-hard usage or hard usage type with No. 12 AWG or larger
conductors with a green grounding conductor and not exceeding 18
inches in length, ,
(b) Supply Receptacle. The receptacle supplying power shall
be located not more than 12 inches from the partition which is
connected to i t . The receptacle supplying groups of partitions
shall be on a separate circuit serving no other loads.
(c) Multiwire Circuits. Individual partitions, or groups of
individual partitions where connected together, shall not
contain multiwire circuits.
(d) Number of Receptacle Outlets. Individual partitions, or
groups opf interconnected individual partitions, shall not
contain more than thirteen 15-ampere 125-volt receptacle outlets.
PANEL COMMENT: This Panel Proposal recognizes the existence of
wired partitions for offices, schools and other applications and
establishes rules concerning the construction and installation
of the electrical system within and feeding these partitions.
This type of equipment contains receptacles and lighting
equipment and is, in the Panel's opinion similar to showcases
which are within the scope of Article 410 and covered in Section
410-29. Section 410-29 served as a source for many of the
proposed requirements.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: B.
NEGATIVE: KNICKREHM.
COMMENTON VOTE:
WELLS: I suppo[t the Panel Recommendation and point out that
subsequent to the meeting, I have become aware of some Panels
with no f l e x i b i l i t y between panels. The Panel should review
410-108 in this context.
EXPLANATION OF VOTE:
KNICKREHM: I t is my belief that this material does not f a l l
within the scope of Article 410. The UL employee who listed
this material before i t was recognized by the NEC is a me~)er of
C~4P 21 and for that reason, I believe, the propbsal was assigned
to CMP 21 for a f a i r appraisal, that i t has recieved, but the
subject does not, in my opinion belong in the Article 410,
chapter 4 "Equipment for General Use" i t should be in chapter 6
"Special Equipment." The Panel Recommendation is good and could
be used with l i t t l e change in a new Article, which should also
include fixture connections by cabIe assembies. The future
effective date is required because a device "identified for this
use" is not now available.
600-5: Accept
C~ 21
SUBMITTER: Allen KnicK~ehm, Los Angeles NECA
PROPOSAL: 68 Delete the reference to "Article 250" and replace
w--1-t'h--~-~-ectlon 250-97." Delete Exception Nos. I and 2.
SUBSTANTIATION: Problem: Bonding rules for signs, etc., appear
in two places and are not the same.
Rules should not be repeated by different C~'s as their
proposal shows. ExceptionNo. I does not provide for safety of
workers as required by OSHA. ExceptionNo. 2 is provided for by
changing the reference to Section 250-97.
I f this proposal is not in compliance with Section 90-3, then
Section 250-97 should be deleted and a reference to signs and
Section 600-5 should be included in Section 250-2.
PANEL RECOMMENDATION: Accept as Revised:
Section 600-5 and Exception No. 1 to remain as is. Revise
Exception No. 2 by adding the words "protected from physical
damage," a~ter the word "conductors."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 600 -- ELECTRIC SIGNS AND OUTLINE LIGHTING
600-5, Exception No. 2: Reject
cMP 21
SUBMITTER: ~Peter Pollak, The Aluminum Association
~ 6 9
After "No. 14" add "copper or No. 12 aluminum. . . . "
~IATION:
This proposal is submitted to c l a r i f y the
proper size equivalent of aluminum conductor for the
application. The size limitation is based upon an ampacity
requirement which can be met with an aluminum conductor sized to
provide the required an~)acity. The panel is referred to the
proposed revision in Section 110-5.
PANEL RECOMMENDATION: Reject,
PANEL COMMENT: Already covered by Section 110-15.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
600-6(c)-(New): Accept
,
CMP 21
SUBMITTER: R. S. Pinkerton, Electrical Code Advisory Committee
for-C-~t-y of Los Angeles
PROPOSAL: 70 Add a new (c) as follows:
~omputed
Load. The load for the required branch circuit
installed for thesupply of exterior signs or outline lighting
shall be computed at a minimum of 1200 watts.
SUBSTANTIATION: Although the Code requires a sign circuit to be
installed, i t does not provide for a minimum computed load for
this circuit. Unrealistically low loads of 180 or 200 watts
have been shown on the i n i t i a l installation which has resulted
in overloaded feeders when the 'real' sign of 1,000-1,500 watts
is installed. The 1,200 watt minimum load is a realistic value
for the average sign installation and will prevent many costly
feeder changes caused by failure to properly provide for the
sign load on the i n i t i a l installation.
PANEL RECOMMENDATION: Accept ~s Revised.
I Change"watts" to "volt-amperes."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 600 -- ELECTRIC SIGNS AND OUTLINE LIGHTING
600-6(c)-(New): Reject
CMP 21
SUBMITTER: J. J. Kark, National Manufacturers Assn.,
71 Add now (c) as follows:
~round-Fault
CircuAt-lnterrupter Required. Receptacles
supplying outdoor portable, cord- and plug-connected signs shall
be protected by a ground-fault circuit-interrupter for personnel.
SUBSTANTIATION: Portable cord- and plug-connected signs used
along the roadside, fed from extension cords at the building
pose an unsafe condition. The signs are constantly exposed to
vandalism and the elements. Their supply is by flexible cords
which may be laid across an active roadway, being repeatedly run
over by vehicles. The signs have metal frames and are often on
rubber tires. I t wasn't until the 1978 Code that portable signs
were required to be grounded. There are numerous signs built
before this change which are s t i l l in use. Therefore, i f a
line-to-frame fault occurs, a person standing on the ground and
touching the frame will provide a ground return path. Even i f
an equipment ground was installed, the usage conditions make i t
unlikely that i t will be adequate for any appreciable time.
Attached are copies of newspaper clippings which document three
(3) deaths and three (3) shocks.. Many enforcement people have
voiced concern regarding this situation.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 73A.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE:~ 8.
NEGATIVE: Short.
EXPLANATION OF VOTE:
SHORT: I feel that this proposal will provide more safety
than Proposal No. 73A which does not protect personnel from
damaged cords.
600-2(b): Accept
CMP 21
SUBMITTER: TSC-Approvedfor the Purpose
]~-RI)-PI~'-AL-~." 67 See the Technical Subcommittee "Recommendations"
un-un-de~--tlTe definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "a type approved for the purpose" and replace
with "rated for controlling inductive load(s)."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
600-4: Accept
CMP 21
SUBMITTER: CMP 21
PROPOSAL: 67A Delete Section 600-4.
~IATION:
This proposal was presented by CMP 21 member,
Walt A. Mueller.
A Task Force has been appointed by the CMP 21 Chairman to
study any possible hardships this section has imposed on the
sign industry.
PANEL RECOMMENDATION: Accept as Revised.
6(]i5--4. Listing Required. Every electric sign of any type,
fixed or portable shall be listed and installed in conformance
with that listing; unless otherwise permitted by special
permission.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NOT VOTING: Duffy.
329
REPORT OF CODE-MAKINGPANEL NO. 10
ARTICLE 422 -- APPLIANCES
422- I : Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
IR-O-I~O-~-AZ~
':I
See the Technical Subcommittee "Recofnmendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the~TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the second sentence.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-3: Accept
CMP 10
SUBMITTER: Claude E. Deering, Jr., American Petroleum Institute
!~TOITO~-~.
" 2
Add the word "classified" in parenthesis after
"hazardous."
SUBSTANTIATION: I t is proposed that the word "classified", in
parentheses, be inserted after the word "hazardeu~." This is
consistent with Article 500, which, is entitled "Hazardous
(Classified) Locations." The proposed wording recognizes that a
location is not hazardous per se, but is classified depending on
the properties of the flammable or combustible substance which
may be present, and the likelihood that a flammable or
combustible concentration or quantity will be present.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-5(a), Exception No. 2: Accept
CMP 10
SUBMII-FER: W. Creighton Schwan, Hayward, CA
I 1~-OPb-~--~.
" 3
Place a comma after the words "motor-operated
~ e . "
SUBSTANTIATION: As the exception is presently punctuated, a 25%
increase in branch circuit rating is required for every
appliance "other than a motor-operated appliance that is
continuously loaded." Revised as proposed, the phrase "that Is
continuously loaded" will properly apply to the appliance in the
opening phrase, "For an appliance," not to "a motor-operated
appl iance."
PANEL RECO~AMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-8(d)(I): Accept
CMP 10
SUBMITTER: S. Mazzoni, Underwriters Laboratories Inc.
I iSR~P~T~~
' AL-~.4
'
Add "SO" after "STO."
~IATION:
Type SJ cord is a Junior Hard Service Cord per
Table 400-4 of the NEC and Is equivalent to SJO, SJT, SJTO and
there is no technical Justification for its exclusion. I
believe that i t was the intent of C~-10 that i t be included and
its exclusion was inadvertent.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-8(d)(I): Reject
CMP 10
SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter, IAEI
5
Reviseto read:
- - - - - ~ R e s i d e n t i a l food waste disposers'. All such equipment
and controls in dwelling type occupancies shall be provided with
an independent disconnecting means within sight of the equipment
and i t shall be readily accessible. Food waste disposers of
one-half horse-power or less shall be wired only with heavy duty
3-wire minimum No. 16 hard service cord and approved cap and
three wire "U" slot grounding type receptacles. On new
construction, a disconnect switch shall be mounted in the wall
adjacent to the sink.
SUBSTANTIATION: To assure the unit is always grounded we
propose the above. Our experience shows space under the sink is
usually used for storage resulting in damage to the connections
of any other wiring methods. Now electrical personnel servicing
these units often do not restore wiring to i t ' s original
condition. The switch provides safety should a foreign object
f a l l into the appliance.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's Intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
I
422-8(d)(2): Accept
CMP 10
SUBMITTER: S. Mazzoni, Underwriters Laboratories Inc.
~ 6
Add "SJ" after "STO."
~O~-ST~N-TIATION: Type SJ cord is a Junior Hard Service Cord per
Tab.le 400-4 of the NEC and is equivalent to SJO, SiT, SOTOand
there is no technical Justification for Its exclusion. I
believe that ~t was the intent of CMP 10 that i t be included and
its exclusion was inadvertent.
PANEL RECOI~4ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-14(a), Exception: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
PR--R~-~O'~-~.7
See the Technical Subcommittee "Recommendations"
un--h-'d-6F-~ITe definition of "Approved for the Purpose" in Article
100. ~
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article I00.
PANEL RECOMMENDATION: Accept as Revised:
Exception: Water heaters with supply water temperature of
180°F or above and a capacity of 60 kW or above and identified
as being suitable for this use; and water heaters with a
capacity of one gallon or less and identified as being suitable
for such use.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-14(b): Accept
CMP 10
SUBMITTER: CMP 2
7A Revise (b) as follows:
~orage-type
Water Heaters. All fixed storage-type water
heaters having a capacity of 120 gallons or less shall have a
branch-circuit rating not less than 125 percent of the nameplate
rating of the water heater.
Delete the fine print note.
SUBSTANTIATION: For clarification of intent.
PANEL RECOMMENDATION: Accept the (b) portion of the proposal.
PANEL COMMENT: CMP feels the fine print note is necessary and
should be retained.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-15(a): Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
8
See the Technical Subcommittee "Recommendatiens"
un--n-d-er--t~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the phrase "approved for the purpose" and replace with
"identified as suitable for use with infrared heating lamps
rated 300 watts or less.
VOTE ON PANELRECOI~ENDATION: UnanimouslyAffirmative.
422-15(b), Exception: Accept
CMP 10
• SUBMITTER: TSC-Approvedfor the Purpose
g
See the Technical Subcommittee "Recommendations~
under t--~e deflnlt$on of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Exception: Lampholders identified as suitable for use with
infrared heating lamps rated more than 300 watts.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-16: Reject
CMP 10
SUBMITTER: G. A. Wintz, Southern California Chapter IAEI
!~TOI~-O-SA
' L-~. 10 Delete the f i r s t paragraph and replace with:
provisions of Article 250 apply to the grounding of
appliances.
SUBSTANTIATION: The present wording "Metal frames of
electrically heated appliances operating on circuits over 150
volts to ground, shall be grounded in the manner specified in
Article 250" is misleading as the requirements of Section 250-42
are more stringent than those of Section 422-16.
The provisions of Section 90-3 do not provide means whereby
requirements of Articles 250 and 422 can differ. The proposal
is intended to eliminate thls inconsistency.
PANEL RECOI~ENDATION: Reject.
PANEL CO¥1~ENT: CMP agrees with the intent of the Proposal. See
action on Proposal No. IOA, Section 422-16.
VOTE ON PANELRECOI~ENOATION: UnanimouslyAffirmative.
422-16: Accept
CMP 10
Secretary's Note: I t was the action of the Correlating
Co~=~ittee that the Panel correlate with Panel S's Proposal
No. 53 on Section 250-60.
SUBMITTER: ~ 10
PROPOSAL: IOA Revise as follows:
Grounding. All exposedmetal parts of appliances
likely to become energized shall be grounded as required in
Article 250.
J
(FPN) See Sections 250-42~ 250-43 and 250-45 for equipment
grounding' of refrigerators and freezers and Sections 250-57 and
250-60 for equipment grounding of electric ranges, wall-mounted
ovens, counter-mounted cooking units, and clothes dryers.
SUBSTANTIATION: ~ 5 is to be advised of this proposal and
requested to delete from Section 250-2 "Appliances Section
422-16" and delete Exception No. 2 toSectlon 250-45(b).
178
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
PANEL RECOMMENDATION: Accept as revised.
422-15. Grounding. Appliancesrequired by Article 250 to be
grounded shall have exposed noncurrent-carrying metal parts
rounded in the manner specified in Article 250.
FPN) See Sections 250-42, 250-43 and 250-45 for equipment
grounding of refrigerators and freezers and Sections 250-57 and
250-60 for equipment grounding of electric ranges, wall-mounted
ovens, counter-mounted cooking units, and clothes dryers.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
~
422-27(a): Accept
CMP 10
SUBMITTER: Idaho Chapter, IAEI
15 Reword422-27(a) to include (f) which would then
(a) Appliances shall be considered as protected against
overcurrent i f supplied by branch circuits as specified in (e)
and (f) below and in Sections 422-5 and 422-6.
SUBSTANTIATION: No direct reference is made to requirements for
overcurrent protection of water heaters of larger types. By
including Part (f) in this section, specific requirements will
be prescribed.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Jordan.
EXPLANATION OF VOTE:
JORDAN: Section-422-27(2) gives requirements for protection
of branch circuits. The (3) references given - "(e), 422-5 and
422-6" - are all requirements for branch circuit protection and
not supplementary protection. There is enough confusion in the
industry as i t is, concerning the difference between
"branch-circuit protection" and supplementary protection."
Let's not promulgate the confusion.
422-16: Reject
CMP 10
SUBMITTER: International Association of Electrical Inspectors
11 Revise the f i r s t paragraph as follows:
Grounding. The provisions of Article 250 apply to the
grounding of appliances.
(No change In the Exception and the remainder of the Section)
SUBSTANTIATION: The present wording "Metal frames of
electrically heated appliances operating on circuits over 150
volts to ground, shall be grounded in the manner specified in
Article 250" is misleading as the requirements of Section 250-42
are more stringent than those of Section 422-16.
The provisions of Section 90-3 do not provide means whereby
requirements of Articles 250 and 422 can differ. The proposal
is intended to eliminate, this inconsistency.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal. See
action on Proposal No. IOA.
VOTE ON PANELRECOI~(ENDATION:, Unanimously Affirmative.
422-27(f), Exception No. 2 b.: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
16 See the Technical Subcommittee "Recommendations"
un--n-a'e~-t-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
b. Elements are completely contained within an enclosure
identified as suitable for this use, or . . . .
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-21(c)-(New): Reject
CMP 10
SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter, IAEI
lPITOITO-~XL-T." 12 Add (c) as follows:
T ~ SpaceHeating Equipment (other than electric heat).
(1) A readily accessible disconnect switch shall be mounted
on the exterior of the heating equipment or on a surface
adjacent to the heating equipment.
(2) Heating equipment which is not readily accessible shall
have an additional disconnect installed at the nearest readily
accessible location.
SUBSTANTIATION: Providing for safety in servicing of the unit,
a disconnect shall be located at the unit. Providing for safety
of the person using the unit, a disconnect means shall be
provided which is readily accessible in the event of f i r m e r
explosion.
PANEL REC~ENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change. Xhe present wording adequately reflects the
Panel's intent. See Sections 422-20, 422-21(b), and 422-26.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Riley.
EXPLANATION OF VOTE:
RILEY: The International Association of Electrical Inspectors
views this'proposal solely on the merit of: "Personnel
Protection" and for no other reason(s).
ARTICLE 424 -- FIXED ELECTRIC SPACEHEATINGEQUIPMENT
424-1: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
17 See the Technical Subcommittee "Recommendations"
the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the second sentence.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-2: Accept
CMP 10
SUBMITTER! Claude E. Deering, Jr., American Petroleum Institute
PROPOSAL: 18 Add the word "classified" in parenthesis after
"hazardous."
SUBSTANTIATION: I t is proposed that the word "classified", in
parenthesis, be inserted after the word "hazardous." This is
consistent with Article 500, which is entitled "Hazardous
(Classified) Locations." The proposed wording recognizes that a
location is not hazardous per se, but is classified depending on
the properties of the flammable or combustible substance which
may be present, and the likelihood that a flammable or
combustible concentration or quantity will be present.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-22(c): Reject
CMP 10
SUBMITTER: O. E. Dillon, Border County Div. IAEI
13 Add the words "fastened in place and" after the
~pllance."
SUBSTANTIATION: This section is practically unenforceable as
t-!~ere is no method of determining the rating of a portable '
appliance which may sometime in the future be plugged into a
receptacle. See the attached opinion* of the San Diego City
Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change. The present wording adequately reflects the
Panel',s intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-3(b)(HOD 1978 NEC): Accept
CMP 10
SUBMITTER: International Association of Electrical Inspectors
19 AmendSection 424-3(b), Paragraph 1, Sentence 1,
to re--6~-6F:
(b) Branch-Circuit Sizing. The size of branch-circuit
conductors and overcurrent protective devices supplying fixed
electric space heating equipment consisting of resistance
elements with or without a motor shall be computed on the basis
of 125-150 percent of the total load of the motors and the
heaters.
SUBSTANTIATION: I t should be recognized that 125 percent is
exacting and practically impossible to obtain. Guide lines were
originally provided in Section 210-20(b) of the 1971NEC.
However, this was deleted in the 1975 NEC. Under our present
requirement, Judgement could rule to pick something less than
125 percent but close to i t and no one can define "close."
Anything less than 125 percent may cause nuisance tripping.
"125-150 percent"Lwill provide the guide lines that are needed.
PANEL RECOMMENDATION: Accept as Revised:
(b) Branch-Circuit Sizing. The ampacity of the branch-circuit
422-27: Reject
CMP 10
SUBMITTER: C. E. Muhleman, Marion, IN
PROPO~ 14 Revise as follows:
Overcurrent Protection. Each appliance of less than 15
amperes load and each cord connected appliance shall have
overcurrent protection built into the appliance or its cord
cap. Appliances having loads equal to or more than 15 amperes
are not connected by cord, may be protected by an overcurrent
device in a dedicated branch circuit. These overcurrent devices
shall not exceed 150 percefit of the appliance load. The
requiraments in (a) thru (d)below, shall apply.
Delete present Ca) and (e). Reidentify remaining paragraphs
(b), (c), (d) and (f).
SUBSTANTIATION: This prevents small faults from not being
detected by a large overcurrent device and will reduce fires and
damage to appliances.
PANEL RECOMMENDATION: Reject.
179
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
PANEL RECOMMENDATION: Accept as revised.
422-15. Grounding. Appliancesrequired by Article 250 to be
grounded shall have exposed noncurrent-carrying metal parts
rounded in the manner specified in Article 250.
FPN) See Sections 250-42, 250-43 and 250-45 for equipment
grounding of refrigerators and freezers and Sections 250-57 and
250-60 for equipment grounding of electric ranges, wall-mounted
ovens, counter-mounted cooking units, and clothes dryers.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
~
422-27(a): Accept
CMP 10
SUBMITTER: Idaho Chapter, IAEI
15 Reword422-27(a) to include (f) which would then
(a) Appliances shall be considered as protected against
overcurrent i f supplied by branch circuits as specified in (e)
and (f) below and in Sections 422-5 and 422-6.
SUBSTANTIATION: No direct reference is made to requirements for
overcurrent protection of water heaters of larger types. By
including Part (f) in this section, specific requirements will
be prescribed.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Jordan.
EXPLANATION OF VOTE:
JORDAN: Section-422-27(2) gives requirements for protection
of branch circuits. The (3) references given - "(e), 422-5 and
422-6" - are all requirements for branch circuit protection and
not supplementary protection. There is enough confusion in the
industry as i t is, concerning the difference between
"branch-circuit protection" and supplementary protection."
Let's not promulgate the confusion.
422-16: Reject
CMP 10
SUBMITTER: International Association of Electrical Inspectors
11 Revise the f i r s t paragraph as follows:
Grounding. The provisions of Article 250 apply to the
grounding of appliances.
(No change In the Exception and the remainder of the Section)
SUBSTANTIATION: The present wording "Metal frames of
electrically heated appliances operating on circuits over 150
volts to ground, shall be grounded in the manner specified in
Article 250" is misleading as the requirements of Section 250-42
are more stringent than those of Section 422-16.
The provisions of Section 90-3 do not provide means whereby
requirements of Articles 250 and 422 can differ. The proposal
is intended to eliminate, this inconsistency.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal. See
action on Proposal No. IOA.
VOTE ON PANELRECOI~(ENDATION:, Unanimously Affirmative.
422-27(f), Exception No. 2 b.: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
16 See the Technical Subcommittee "Recommendations"
un--n-a'e~-t-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
b. Elements are completely contained within an enclosure
identified as suitable for this use, or . . . .
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-21(c)-(New): Reject
CMP 10
SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter, IAEI
lPITOITO-~XL-T." 12 Add (c) as follows:
T ~ SpaceHeating Equipment (other than electric heat).
(1) A readily accessible disconnect switch shall be mounted
on the exterior of the heating equipment or on a surface
adjacent to the heating equipment.
(2) Heating equipment which is not readily accessible shall
have an additional disconnect installed at the nearest readily
accessible location.
SUBSTANTIATION: Providing for safety in servicing of the unit,
a disconnect shall be located at the unit. Providing for safety
of the person using the unit, a disconnect means shall be
provided which is readily accessible in the event of f i r m e r
explosion.
PANEL REC~ENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change. Xhe present wording adequately reflects the
Panel's intent. See Sections 422-20, 422-21(b), and 422-26.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Riley.
EXPLANATION OF VOTE:
RILEY: The International Association of Electrical Inspectors
views this'proposal solely on the merit of: "Personnel
Protection" and for no other reason(s).
ARTICLE 424 -- FIXED ELECTRIC SPACEHEATINGEQUIPMENT
424-1: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
17 See the Technical Subcommittee "Recommendations"
the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the second sentence.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-2: Accept
CMP 10
SUBMITTER! Claude E. Deering, Jr., American Petroleum Institute
PROPOSAL: 18 Add the word "classified" in parenthesis after
"hazardous."
SUBSTANTIATION: I t is proposed that the word "classified", in
parenthesis, be inserted after the word "hazardous." This is
consistent with Article 500, which is entitled "Hazardous
(Classified) Locations." The proposed wording recognizes that a
location is not hazardous per se, but is classified depending on
the properties of the flammable or combustible substance which
may be present, and the likelihood that a flammable or
combustible concentration or quantity will be present.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
422-22(c): Reject
CMP 10
SUBMITTER: O. E. Dillon, Border County Div. IAEI
13 Add the words "fastened in place and" after the
~pllance."
SUBSTANTIATION: This section is practically unenforceable as
t-!~ere is no method of determining the rating of a portable '
appliance which may sometime in the future be plugged into a
receptacle. See the attached opinion* of the San Diego City
Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change. The present wording adequately reflects the
Panel',s intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-3(b)(HOD 1978 NEC): Accept
CMP 10
SUBMITTER: International Association of Electrical Inspectors
19 AmendSection 424-3(b), Paragraph 1, Sentence 1,
to re--6~-6F:
(b) Branch-Circuit Sizing. The size of branch-circuit
conductors and overcurrent protective devices supplying fixed
electric space heating equipment consisting of resistance
elements with or without a motor shall be computed on the basis
of 125-150 percent of the total load of the motors and the
heaters.
SUBSTANTIATION: I t should be recognized that 125 percent is
exacting and practically impossible to obtain. Guide lines were
originally provided in Section 210-20(b) of the 1971NEC.
However, this was deleted in the 1975 NEC. Under our present
requirement, Judgement could rule to pick something less than
125 percent but close to i t and no one can define "close."
Anything less than 125 percent may cause nuisance tripping.
"125-150 percent"Lwill provide the guide lines that are needed.
PANEL RECOMMENDATION: Accept as Revised:
(b) Branch-Circuit Sizing. The ampacity of the branch-circuit
422-27: Reject
CMP 10
SUBMITTER: C. E. Muhleman, Marion, IN
PROPO~ 14 Revise as follows:
Overcurrent Protection. Each appliance of less than 15
amperes load and each cord connected appliance shall have
overcurrent protection built into the appliance or its cord
cap. Appliances having loads equal to or more than 15 amperes
are not connected by cord, may be protected by an overcurrent
device in a dedicated branch circuit. These overcurrent devices
shall not exceed 150 percefit of the appliance load. The
requiraments in (a) thru (d)below, shall apply.
Delete present Ca) and (e). Reidentify remaining paragraphs
(b), (c), (d) and (f).
SUBSTANTIATION: This prevents small faults from not being
detected by a large overcurrent device and will reduce fires and
damage to appliances.
PANEL RECOMMENDATION: Reject.
179
The wire manufacturers do not have a standard production of
2/0 and 3/0 cable required for the 30 kW and 35 kW and larger
space heaters. Most of the contractors have to special order
this material.
The NEC should, as always, give the industry the method for a
safe installation for the protection of the public, but let our
inspectors in charge determine the method.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
conductors and the rating or setting of overcurrent protective
devices supplying fixed electric space heating equipment
consisting of resistance elements with or without a motor shall
not be less than 125 percent of the total load of the motors and
the heaters. The rating or setting of overcurrent protective
devices shall be permitted in accordance with Section 240-3,
Exception No. i .
PANEL COMMENT: Reaffirm CMP 10 action for Proposal No. 30 (1978
Preprint) for the f i r s t sentence of the f i r s t paragraph of
Section 424-3(b).
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Erickson.
EXPLANATION OF VOTE:
ERICKSON: Section 330-15 is specific on "maximum continuous
capacities" for conductors. For thls Panel to add a derating
factor of 80% is an unnecessary economic penalty. In some
instances the branch-circuitprotective device is required to be
derated because of other sections of the Code, and this will
have some effect on conductor sizing, but that should not lead
us to make an across-the-board derating of conductors.
I can support this proposal i f i t is revised to read:
(b) Branch Circuit-Sizing. The ampacity of the branch-circuit
conductors supplying fixed electric space heating equipment
consisting of resistance elements and one or more motors shall
be in accordance with Section 210-22(a). The ampacity of the
branch-circuit conductors supplying fixed electric space heating
equipment consisting of resistance elements only shall be in
accordance with Section 310-15. The rating or setting of
overcurrent protective devices shall be in accordance with
Section 200-3, Exception No. i and Section 210-22(c) where
applicable.
424-19(a)(2)c.: Reject
CMP 10
SUBMITTER: Robert G.' MacManus, Pawtucket, RI
22 Add a sentence as follows:
Where more than one controller is used to control one or
motors, as in the case of a thermostat, aquastat, summer-winter
switch or time switch, a single disconnecting means shall be
provided that will open the circuit to all controllers and also
be capable of being locked in the open position i f not in sight
from the controller locations.
SUBSTANTIATION: Any of the above controllers may be the motor
controller at a given time and i t would be impractical to
install a disconnecting means in sight from each. A single
lockable switch would prevent a hazard which now exists.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-14: Accept
CMP 10
SUBMITTER: O. E. Dillon, Border County Div. IAEI
20 Delete the phrase " l i k e l y to become energized."
~IATION:
The use of the words " l i k e l y to become
energized" renders this section unenforceable. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for CMP I Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Accept as Revised.
424-14. Grounding. All exposed "noncurrent-carrying" metal
parts of fixed electric space heating equipment l i k e l y to become
energized shall be grounded as required in Article 250.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
424-22(a) Exception-(New)(HOD 1978 NEC):
CMP 10
Reject
SUBMITTER: J.A. Pietsch, General Electric Company
PROPOSAL: 23 Add exception to Section 424-22(a) as follows:
~ i o n :
Where the branch-circuit, short-circuit and
ground-fault protector is rated 60 amps or less and 250 volts 6r
less, either fuses or inverse time-type circuit breakers maybe
installed unless otherwise-limited by marking on the equipment
nameplate.
SUBSTANTIATION: The intent of this proposal and a related
proposal to change Section 440-22(b) is to permit the use of
inverse time-type circuit breakers where appropriate on fixed
Heating, Air Conditioning and Refrigeration Equipment branch
circuits.
Successful results with specific equipments approved as
individual types or models for circuit breaker branch-circuit
protection have shown that such devices do not constitute a
safety hazard. And, the circuit breakers permit improved
protection to power utilization equipment by disconnecting " a l l "
ungrounded supply conductors s!multaneously.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal see
action on Proposal No. 24, Section 424-22(a).
VOTE ON PANELRECOMa4ENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
JORDAN: My vote is to reject, as is the Panel's vote, but not
for the same reason. See Proposal No. 24.
424-19: Reject
CMP 10
SUBMITTER: T.H. Halton, Jr., Fort Worth, TX
21 Revise as follows:
Disconnecting Means. Means shall be provided to
disconnect all fixed electric space heating equipment from all
ungrounded conductors. Where heating equipment is supplied on
more than one source, the disconnecting means shall be grouped
and identified.
(a) For fixed electric space heating equipment rated at not
overdO0 vo!t-amperes or 1/8 horsepower, the branch-circuit
overcurrent device may serve as the disconnecting means.
(b) For fixed electric space heating equipment of greater
rating, the branch-circuit switch or circuit breaker may, where
readily accessible to the user of the equipment, serve as the
disconnecting means.
(c) Motor Driven Heating Equipment. A switch or circuit
breaker that serves as the disconnecting means for a
motor-driven heater having a motor more than I/8 horsepower
shall be located within sight of the motor controller.
(d) Unit Switches as'Disconnecting Means. Unit switches with
a marked "Off" position, which are part of a fixed heater, that
disconnect all ungrounded conductors may be used as the
disconnecting means required by the Article when other means for
disconnection are provided in the following types of occupancies:
(i) Multifamily Dwellings. In multifamily (mo~ethan two)
dwellings, the other disconnecting means shall be within the
apartment, or on the same floor as the apartment in which the
fixed heater is installed, and may also control lamps and
appliances.
(2) Two-Family Dwellings. In two-family dwellings, the
other disconnecting means may be located either inside or
outside of the apartment in which the fixed heater is installed.
(3) Single-Family Dwellings. In single-family dwellings,
the service disconnecting means may be the other disconnecting
means.
(4) Other Occupancies. In other occupancies, the
branch-circuit switch or circuit breaker, where readily
accessible to the user of the fixed heater, may be used for the
other disconnecting means.
SUBSTANTIATION: The members of Code Making Panel No. 10 have
been working on this Section for some time, however this is an
example of trying to write a Code Section on how to install
electrical work. The Code has always been a performance Code,
not technical.
This proposal shall let the area inspector determine how to
install electrical space heating. The u t i l i t y companies are not
trying to require the methods for an installation of space heat
now as they have in the past.
424-22(a), Exception-(New): Accept
CMP 10
Secretary's Note: I t was the action of the Correlating
Committee that this Proposal should be clarified as not applying
to motor operated equipment. Otherwise i t is the responsibility
of Panel 11.
SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.
24 Add Exception as follows:
~ i o n :
Where the branch-circuit, short-circuit and
ground-fault protection is rated 60 amps or less and 250 volts
or less, and where the available fault current is 5000 amps or
less, either fuses or inverse tlme-type c i r c u i t breakers may be
installed unless otherwise limited by marking on the equipment
nameplate.
SUBSTANTIATION: The intent of this proposal and a related
proposal to change 440-22(b) is to permit the use of
inverse-time type circuit breakers where appropriate on fixed
heating, air conditioning and refrigeration equipment branch
circuits.
A UL Fact-Finding Report dated November 1, 1976 was conducted
to investigate the s u i t a b i l i t y of inverse-time circuit breakers
for these applications.
Unfortunately, close timing between issuance of the Report and
the final vote by the panel l e f t l i t t l e time for thorough study
for the 1978 Code.
A careful review indicates that circuit breakers were t o t a l l y
acceptable in 97% of the 387 tests summarized in the report.
The remaining tests had minor discrepancies.
A f i e l d survey included in the report indicates that over 50%
of the defined units installed since 1971 are in fact protected
by circuit breakers with no f i e l d problems.
PANEL RECOMMENDATION: Accept as Revised:
Delete the word "may" and replace with "shall be permitted to."
180
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Casella, Hoeck, Jordan.
EXPLANATION OF VOTE:
CASELLA: This proposal would be acceptable i f the wording
"identified for group installation" were inserted after the
present wording "inverse time type circuit breakers."
HOOCK: I have voted negative on this same Proposal and other
similar proposals in the past and feel that this issue should
not be asked to be resolved by CMP 10. I believe this is a
design problem and should be resolved between the testing agency
and equipment manufacturers.
JORDAN: Much rhetoric has been written on this subject, so I
shall endeavor to confine my remarks to the bare minimum. This
proposal is not new having been f i r s t made in a similar proposal
by the same proposer for the 1968 NEC.
As I see this proposal, there is intent to circumvent the
present Code requirements (namely-Section 430-53(c)(3)) which
would allow circuit breakers for the proposed application,
should these devices be "approved" for group installation. The
NEC is not a testing agency and should not validate product
safety or mandate acceptance of a product that has not been able
to gain testing lab certification.
I t is my opinion that a nationally recognized testing lab should
c e r t i f y that this application is proper and safe and l i s t
and/label said equipment when submitted by the manufacturer.
The mechanics are already in the NEC. Why legislate performance
by the NEC?
/
clearly. I personally believe that our Code should mainly staj,
on the performance side. This change back to the original Code
w i l l enable the Inspectors to perform their duties on a more
equal and safer installation.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not Justify the
proposed change.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
424-22(e): Accept
CMP 10
SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc.
27 Revise as follows:
~onductors
For Subdivided Loads. Field wired conductors
between the heater and the supplementary overcurrent devices
shall have the same ampacity as required for branch-circuit
conductors in accordance with Section 424-3(b) based on the
connected load. The supplementary overcurrent protective
devices specified in (c) above shall protect these conductors in
accordance with Section 240-3.
SUBSTANTIATION: The present wording of Section 424-22(e)
apparently rules out the use of Exception No. I to Section
240-3, which I do not believe was intended. Furthermore, the
Exception to 424-22(e) was apparently based on the Exception to
424-22(d). I t is my understanding that the basis for the
exception to 424-22(d) is that on large heaters having
individually controlled subdivided loads i t is unlikely that all
of these individual loads will be energized simultane- ously for
extended periods of time and therefore the conductors supplying
the supplementary overcurrent protective devices would not be
carrying the total heater current for extended periods. However,
this logic is not applicable to the subdivided loads where i t is
quite common for one or more such loads to be energized
continuously in large heater (50 Kw or more).
PANEL RECOMMENDATION: Accept as Revised:
(el Conductors For Subdivided Loads. Field-wired conductors
between the heater and the supplementary overcurrent protective
devices shall be sized at not less than 125 percent of the load
servedt The supplementary overcurrent protective devices
specified in (c) shall protect these conductors in accordance
with Section 240-3.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 9.
NEC~TIVE: Erickson.
EXPLANATION OF VOTE:
ERICKSON: We are sizing conductors in this section and they
do not have to be derated for continuous duty in accordance with
Section 310-15. To continually oversize conductors is an
unnecessary economic penalty. See comments on Proposal No. 19.
424-22(b) and (c): Accept
CMP '10
SUBMIITER: D. C. Rockholm, Underwriters Laboratories Inc.
PROPOSAL: 25 Revise as follows:
~esistance
Elements. Resistance-type heating elements in
electric space heating equipment shall be protected at not more
than 60 amperes. Equipment employing such elements rated more
than 48 amperes shall have the heating elements subdivided, and
each subdivided load shall not exceed 48 amperes.
Exception: As provided in Section 424-72(a).
(c) Overcurrent Protective Devices. The supplementary
overcurrent protective devices for the subdivided loads
specified . . . .
SUBSTANTIATION: The present wording of Section 424-22(b) does
not place any limit on the size of overcurrent protecti6n of
electric space heating equipment rated 48 amperes or less. I do
not believe i t was ever intended to allow such equipment to be
protected with a larger size overcurrent protective device than
permitted for an identical subdivided load of a large heater.
The proposed rewording in Section 424-22(b) would correct ~his
apparent oversight but would also require the addition of the
words "for the subdivided loads" to 'Section 424-22(c) to define
the overcurrent protective devices referenced in this Section.
PANEL RECOMMENDATION: Accept as Revised.
Add a paragraph to the end of (b) as follows:
Where a subdivided load is less than 48 amperes, the rating of
the overcurrent protective device shall comply with Section
424-3(b).
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
I can support this proposal i f i t is reworded to ~ead:
(el Conductors for Subdivided Loads. Field wired conductors
between the heating elements and supplementary overcurrent
protective devices shall be sized in accordance with Section
310-15 and shall be protected by the supplementary overcurrent
protective devices in accordance with Section 240-3, Exception
No. 1.
424-34, Exception-(New): Accept
CMP 10
SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.
28 Add an exception as follows:
-~-eption: Panels approved for the purpose shall be permitted
with shorter leads.
SUBSTANTIATION: The present wording does not allow for the
installation of heating panels approved for the purpose using
wiring systems other than 7 foot nonheating leads. The addition
of this exception will correct this.
PANEL RECOMMENDATION: Accept as Revised:
Exception: Heating panels identified for direct f i e l d
connections to the nonheating leads using junction assemblies.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
424-22(c): Reject
CMP 10
SUBMITTER: T.H. Halton, Jr.
26 Wording to be deleted.
~ d e d
Text: Delete paragraph (c) Overcurrent PrOtection
Devices.
i
SUBSTANTIATION: This is a cempanion proposal to c l a r i f y the
recommendation for the proposal on 424-19.
In the Tarrant County area of Texas we have had complaints by
the homeowner trying to replace the fuses and of being shocked.
All of their cemplaints were checked and all units were wired
according to N.E.C. including the marking on the units with
notices to disconnect unit before removing any doors.
The homeowner tries to replace these fuses because he has
called in the repairman to f i x his furnace and the repairman
does not always disconnect the unit, he will pull the fuses and
check them. I f he finds one blown he replaces said fuse and
sends a b i l l for or collects for the call. The next time the
unit quits, the homeowner goes by the nearest store and will
purchase enough fuses to replace all fuses in furnace. He
attempts to put in new fuses and not being equipped, nor knowing
what he is doing, will be shocked. The public will t r y to do
anything to save money. The fuses in the units are a hazard to
the public and service men.
The proposed change in Article 424-19 will enable the
electrical inspector to have installed a sub-panel in the heater
closet and connect the electric furnace from that panel.
The heating unit manufacturers are making their units over 20
kW with one feed and two feed connections. This creates a
problem for the installer. He installs for two feeds and on the
final finds a one feed. The larger units requiring 30 kW and 35
kW feeds create problems with the 2/0 and 3/o cable as no
manufacturer of cable has a standard production of this size
cable.
This Section of the N.E.C. as i t is presently in the Code, is
another example of writing a technical Code. No reflection on
our wonderful Code Panels, they work so hard to write the Code
424-35 (a): Accept
CMP 10
SUBMITTER: TSC-Nominal Voltage
PROPOSAL: 29 The second sentence should be revised to read:
wire shall have the following color identification to
indicate the circuit voltage on which i t is to be used, etc.
SUBSTANTIATION: To conform to the method to express circuit
voltage as per guidelines developed by the TSC on nominal
voltage.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
424-41(e): Accept
CMP 10
SUBMITTER: TSC-Approved for the Purpose
30
See the Technical Subcommittee "Recommendations"
under the definiton of "Approved for the Purpose" in Article 100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
181
PANEL RECOMMENDATION: Accept as Revised:
Delete the phrase "approved for the purpose" and replace with
"identified as suitable for this use."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-60: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
PROPOSAL: 34 See the Technical Subcommittee "Recommendations"
un--6-d-e-r-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Delete the words "approved for the purpose and so marked" and
replace with "identified as suitable for use at the elevated
temperatures."
Delete the paranthetical phrase "(such as heat pumps)."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmatfve.
424-41(f), Exception: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
31 See the Technical Subcommittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
Exception: Cables identified to be secured at intervals not
to exceed 6 feet.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-65: Reject
CMP 10
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
35 Add the word "safely" before the word
"accessible."
SUBSTANTIATION: Duct heater controllers are being installed in
locations which have the proper workspace but are impossible to
"reach for routine maintenance without subjecting the workman to
serious risks of tripping and failing. The present Code
requirements provide for a safe workspace about equipment but do
not provide for a safe passageway to the workspace.
PANEL RECOt~NIENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change. The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-44(e): Accept
CMP 10
SUBMITTER: H.F. van der Voort, Cleveland, OH
]~TOI~'AI~T.. 32 Add "rigid nonmetallic conduit" after
~diate
metal conduit" and "electrical metallic tubing."
SUBSTANTIATION: The rigid nonmetallic conduit for this
application is Schedule 40 PVC and has excellent mechanical
strength; both crush and impact. This strength is equivalent to
that of EMT and the proposed wording indicates this. Unless
severe physical damage is imminent, protection of the conduit is
unnecessary. Carlon tested both Schedule 40 and EMT in its own
research f a c i l i t i e s to demonstrate this. The test methods are
those calIed for in UL651. The test results are shown on the
following table.
424-65: Reject
CMP 10
SUBMITTER: SouthwesternSection IAEI
PROPOSAL: 36 Add the word "safely" in front of "accessible" to
read: Duct heater controller equipment shall be safely
accessible with the disconnecting means installed at or within,
site from the controller.
SUBSTANTIATION: Duct heater controllers are being installed in
locations which have the proper workspace but are impossible to
reach for routine maintenance without subjecting the workman to
serious risks of tripping and falling. The present Code
requirements provide for a safe workspace about equipment but do
not provide for a safe passageway to the workspace.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change. The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
I~ACT RESISTANCEMEAS~EMENTS ON PVC SCHEDULE40
CONDUIT & EbECTRICAL METALLIC TUBING
Percent Decrease in Inside Diameter
DIAMETER
Inches
1/2
3/4
1
I-1/4
1-1/2
2
3
4
@VC SCHEDULE 40
Min.
Max.
4.7
4.9
5.5
4.6
4.7
2.1
2.5
2.0
7.2
6.9
5.7
4.8
5.5
2.8
3.0
2.0
EMT
Min.
Max.
18.2
22.6
30.0
26.6
43.6
55.1
53.6
45.1
25.1
25.9
32.9
27.8
45.1
56.6
56.0
46.6
424-71: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
~ 3 7
See the Technical Subcommittee "Recommendations
o - - ~ o v e d for the Purpose" in Article 100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
424-71. Identification. Resistance-type boilers shall be
identified as suitable for the installation.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Crushload in Pounds to Achieve
30% Deflection
DIAMETER
Inches
1/2
3/4
I
1-I/4
1-1/2
2
3
4
PVC SCHEDULE 40
Min.
Max.
2265
1878
1876
1494
1880
1208
1676
1280
2345
1910
2010
1580
1892
1276
1688
1570
EMT
Min.
Max.
2565
2100
2250
2750
1730
1280
,880
785
2800
2160
2365
2950
1764
1296
957
798
424-72(a), (b), and (c): Accept
CMP 10
SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc.
PI~-O]~'~-~." 38 Revise as follows:
- - ~
boiler employing reslstance-type immersion heating
elements contained in an ASMErated and stamped vessel shall
have the heating elements protected at not more than 150
amperes. Such a boiler rated more than 120 amperes shall have
the heating elements subdivided into loads not exceeding 120
amperes.
(b) A boiler employing resistance-type heating elements not
contained in an ASMErated and stamped vessel, shall have the
heating elements protected'at not more than 60 amperes. Such a
boiler rated more than 48 amperes will have the heating'elements
subdivided into loads not exceeding 48 amperes.
(c) The supplementary overcurrent protective devices for the
subdivided loads as required by. . . .
SUBSTANTIATION: The present wording of Section 424-72(b) does
not place any limit on the size of overcurrent protection of
resistance type immersion heating elements in boilers rated 48
amperes or less when the elements are not contained in an ASME
rated and stamped vessel. I do not believe i t was ever intended
tO a11ow such elements to be protected with a larger size
overcurrent protective device than permitted for an identical
subdivided load of a larger boiler. The proposed rewording of
424-72(b) is intended to correct this apparent oversight. The
proposed rewording to 424-72(a) is for clarification and
consistency with 424-72(b). The proposed rewording in Section
424-72(a) and (b) would also require the addition of the words
"for the subdivided loads" to Section 424-72(c) to define the
overcurrent protective devices referenced in this section.
PANEL RECOMMENDATION: 'Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Erickson.
EXPLANATION OF VOTE:
ERICKSOH: No co~Inent received.
424-58: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
33 See the Technical Subcommittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
i PANELRECOMMENDATION: Accept as Revised:
424-58. Identification. Heaters installed in an air duct shall
be identified as suitable for the installation.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
182
through the pressure vessel shell.
As indicated on the sketch, the halar coated heads and the
polysulfone shield act to form an electrically isolated chamber
for the electrode assembly. The PPS bushing insulates the
entire electrode assembly from the steel pressure vessel.
The electrically "hot u electrodes are isolated from the
support shaft and rotating shaft by ceramic arms supported by
polysulfone discs. The rotating shaft i f further isolated by
encapsulation in teflon tubing. A top guard of perforated metal
enclosing the exposed components prevents personnel from
contacting any portion of the assembly. Since the electrode
assenfoly is insulated from the inside of the tank, i t is not
necessary to bring the neutral from the supply to the boiler.
However, we do connect the electrode assembly structure to
neutral to prevent any possible personnel hazard. The outer
enclosure is locally grounded.
I t is understood that the Electrode Boiler has met the .S amp
maximum ground current tests as specified by the Underwriters
Laboratories, Inc. The proposed recommended text attempts to
address the above problem.
PANEL RECO~4ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
PANEL RECOI~ENDATION: Accept as Revised:
In the second sentence of (b) change ~will" to "sh~ll." And,
also add a paragraph to (a) as follows:
Where a subdivided load is less than 120 amperes, the rating
of the overcurrent protective device shall comply with Section
424-3(b).
Add a paragraph to (b) as follows:
Where a subdivided Ibad is less than 48 amperes, the rating of
the overcurrent protective device shall comply with Section
424-3(b).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-72(e): Accept
CMP 10
SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc.
]~TOPO~'7~-~. 39 Revise as follows:
~onductors
for Subdivided Loads. Field-wired conductors
between the heater and the supplementary overcurrent devices
shall have the same ampacity as required for branch-circuit
conductors in accordance with Section 424-3(b) based on the
connected load. The supplementary overcurrent protective
devices specified i n ( c ) above shall protect these conductors in
accordance with Section 240-3.
SUBSTANTIATION: The present wording of Section 424-72(e)
apparently rules out the use of Exception No. 1 to Section
240-3, which I do not believe was intended. Furthermore the
Exception to 424-72(e) was apparently based on the Exception to
424-72(d). I t is my understanding that the basis for the
exception to 424-72(d) is that on large heaters having
individually controlled subdivided loads i t is unlikely that all
of these individual loads will be energized simultaneously for
extended periods of tlme and therefore the conductors supplying
the supplementary overcurrent protective devices would not be
carrying the total heater current for extended periods.
However, this logic is not applicable to the subdivided loads
where i t is quite common for one or more such loads to be
energized continuously in a large heater (50 Kw or more).
PANEL RECOMMENDATION: Accept as Revised:
(e) Conductors for Subdivided Loads. Field-wired conductors
between the heater and the supplementary overcurrent protective
devices shall be sized at not less than 125 percent of the load
served. The supplementary overcurrent protective devices
,
specified in (c) shall protect these conductors in accordance
with Section 240-3.
VOTEON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Erickson.
EXPLANATION OF VOTE:
ERICKSON: No comment received.
ARTICLE 426 -- FIXEDOUTDOORELECTRIC DE-ICINGAND
SNOWMELTING'EQUIPMENT
426-3 Exception-(New)(HOD 1978 NEC): Reject
CMP 10
SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH
~ 4 3
Add at end of paragraph:
~ i o n :
Skin effect current tracing circuits. See Section
426-34.
SUBSTANTIATION: Sameas Proposal No. 57 to 1978 preprint.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with intent of proposal. See action
on Proposal No. 46.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
•
424-80: Accept
CMP 10
SUBMITTER: TSC-Nominal Voltage
]I~-OPI~I~-L'~." 40 Add "nominal~ after the word "volts" in second
"426-23: Reject
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
~ 4 4
See the Technical Subcommittee "Recommendations"
un-'n-de-~'-t-~e definition of "Approved for the purposeu in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved/for the Purpose" in Article 100.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See CMP action on Proposal No. 46.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ERICKSON: I feel that Panel Comment should be changed to "CMP
agrees with intent of Proposal." See action on Proposal No. 46.
426-23: Reject
CMP 10
SUBMITTER: Warren H. Cook, IEEE
~ 4 5
Revise f i r s t sentence to read:
~supply
nonheating leads (cold leads) for the electric
beating elements shall be suitable for the temperature
encountered.
SUBSTANTIATION: Present wording allows for only factory
assembled units. Currently approved equipment is available
which utilizes field fabrication on nonheatlng leads.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See action on Proposal No. 46.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ERICKSON: Sameas for Proposal No. 44. '
SUBSTANTIATION: To conform to the method to express system
voltage as developed by the TSC on nominal voltage.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-81: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
PROPOSAL: 41 See the Technical SubCommittee "Recommendations"
un-G~-a-e~'-]~e definition of "Approved for the l)urpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
424-81. Identification. Electrode-type boilers shall be
identified as suitable for the installation.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
426 Part O-(New)(HOD 1978 NEC): Accept
CMP 10
Secretary's Note: I t was the action of the Correlating
Committee that further consideration be given to the comments
expressed in the voting.
SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH
46 Add a new Part D to Article 426 as follows:
D. Skin Effect Current Tracing
426-30. Scope. The provisions of Part D of thls article shall
apply to fixed outdoor electric de-icing or snow melting
equipment utilizing a tubular resistive heating element of
ferromagnetic material and having within the tubular element an
electrically insulated return conductor so arranged that the
skin effect of alternating current causes the main heating
current to concentrate near the inner wall of the tubular
element.
426-31. Insulating Rating.
(a) The electrical insulation of the inner conductor shall
have a temperature rating greater than the operating temperature
of the cable for the specific system based on the designs and
tests of the manufacturer.
(b) The electrical insulation of the inner conductor shall
have a voltage rating at any point on the system higher than the
operating voltage at that point.
(c) The outer conductor (tubular element) shall not require
electrical insulation provided its outer surface is effectively
grounded at one or more locations. •
424-85: Accept
CMP 10
SUBMI1-TER: Kenneth W. Cohen, Aerco International, Inc.
42 Revise as follows:
~ o s e
boilers designed such that fault currents do not
pass through the presssure vessel and the pressure vessel is
electrically isolated from the electrodes, all exposed
noncurrent carrying metal parts including the pressure vessel,
supply and return connecting piping shall be grounded in
accordance with Article 250.
For all other designs the pressure vessel containing the
electrodes shall be-isolated and electrically insulated fr~n
ground.
SUBSTANTIATION: Aerco International, Inc. presently
manufactures an electrode Hot Water Boiler that is U.L. listed
(U.L. File #E-39417)
I have enclosed a pictoral representation of same.
We believe the grounding requirement, Para. 424-85 of the 1978
NEC is designed to cover those boilers where fault currents can
flow to neutral. However, the code '~oes not specifically
address our design, where fault currents cannot flow to ground
183
through the pressure vessel shell.
As indicated on the sketch, the halar coated heads and the
polysulfone shield act to form an electrically isolated chamber
for the electrode assembly. The PPS bushing insulates the
entire electrode assembly from the steel pressure vessel.
The electrically "hot u electrodes are isolated from the
support shaft and rotating shaft by ceramic arms supported by
polysulfone discs. The rotating shaft i f further isolated by
encapsulation in teflon tubing. A top guard of perforated metal
enclosing the exposed components prevents personnel from
contacting any portion of the assembly. Since the electrode
assenfoly is insulated from the inside of the tank, i t is not
necessary to bring the neutral from the supply to the boiler.
However, we do connect the electrode assembly structure to
neutral to prevent any possible personnel hazard. The outer
enclosure is locally grounded.
I t is understood that the Electrode Boiler has met the .S amp
maximum ground current tests as specified by the Underwriters
Laboratories, Inc. The proposed recommended text attempts to
address the above problem.
PANEL RECO~4ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
PANEL RECOI~ENDATION: Accept as Revised:
In the second sentence of (b) change ~will" to "sh~ll." And,
also add a paragraph to (a) as follows:
Where a subdivided load is less than 120 amperes, the rating
of the overcurrent protective device shall comply with Section
424-3(b).
Add a paragraph to (b) as follows:
Where a subdivided Ibad is less than 48 amperes, the rating of
the overcurrent protective device shall comply with Section
424-3(b).
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-72(e): Accept
CMP 10
SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc.
]~TOPO~'7~-~. 39 Revise as follows:
~onductors
for Subdivided Loads. Field-wired conductors
between the heater and the supplementary overcurrent devices
shall have the same ampacity as required for branch-circuit
conductors in accordance with Section 424-3(b) based on the
connected load. The supplementary overcurrent protective
devices specified i n ( c ) above shall protect these conductors in
accordance with Section 240-3.
SUBSTANTIATION: The present wording of Section 424-72(e)
apparently rules out the use of Exception No. 1 to Section
240-3, which I do not believe was intended. Furthermore the
Exception to 424-72(e) was apparently based on the Exception to
424-72(d). I t is my understanding that the basis for the
exception to 424-72(d) is that on large heaters having
individually controlled subdivided loads i t is unlikely that all
of these individual loads will be energized simultaneously for
extended periods of tlme and therefore the conductors supplying
the supplementary overcurrent protective devices would not be
carrying the total heater current for extended periods.
However, this logic is not applicable to the subdivided loads
where i t is quite common for one or more such loads to be
energized continuously in a large heater (50 Kw or more).
PANEL RECOMMENDATION: Accept as Revised:
(e) Conductors for Subdivided Loads. Field-wired conductors
between the heater and the supplementary overcurrent protective
devices shall be sized at not less than 125 percent of the load
served. The supplementary overcurrent protective devices
,
specified in (c) shall protect these conductors in accordance
with Section 240-3.
VOTEON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Erickson.
EXPLANATION OF VOTE:
ERICKSON: No comment received.
ARTICLE 426 -- FIXEDOUTDOORELECTRIC DE-ICINGAND
SNOWMELTING'EQUIPMENT
426-3 Exception-(New)(HOD 1978 NEC): Reject
CMP 10
SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH
~ 4 3
Add at end of paragraph:
~ i o n :
Skin effect current tracing circuits. See Section
426-34.
SUBSTANTIATION: Sameas Proposal No. 57 to 1978 preprint.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with intent of proposal. See action
on Proposal No. 46.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
•
424-80: Accept
CMP 10
SUBMITTER: TSC-Nominal Voltage
]I~-OPI~I~-L'~." 40 Add "nominal~ after the word "volts" in second
"426-23: Reject
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
~ 4 4
See the Technical Subcommittee "Recommendations"
un-'n-de-~'-t-~e definition of "Approved for the purposeu in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved/for the Purpose" in Article 100.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See CMP action on Proposal No. 46.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ERICKSON: I feel that Panel Comment should be changed to "CMP
agrees with intent of Proposal." See action on Proposal No. 46.
426-23: Reject
CMP 10
SUBMITTER: Warren H. Cook, IEEE
~ 4 5
Revise f i r s t sentence to read:
~supply
nonheating leads (cold leads) for the electric
beating elements shall be suitable for the temperature
encountered.
SUBSTANTIATION: Present wording allows for only factory
assembled units. Currently approved equipment is available
which utilizes field fabrication on nonheatlng leads.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See action on Proposal No. 46.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ERICKSON: Sameas for Proposal No. 44. '
SUBSTANTIATION: To conform to the method to express system
voltage as developed by the TSC on nominal voltage.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
424-81: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
PROPOSAL: 41 See the Technical SubCommittee "Recommendations"
un-G~-a-e~'-]~e definition of "Approved for the l)urpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
424-81. Identification. Electrode-type boilers shall be
identified as suitable for the installation.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
426 Part O-(New)(HOD 1978 NEC): Accept
CMP 10
Secretary's Note: I t was the action of the Correlating
Committee that further consideration be given to the comments
expressed in the voting.
SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH
46 Add a new Part D to Article 426 as follows:
D. Skin Effect Current Tracing
426-30. Scope. The provisions of Part D of thls article shall
apply to fixed outdoor electric de-icing or snow melting
equipment utilizing a tubular resistive heating element of
ferromagnetic material and having within the tubular element an
electrically insulated return conductor so arranged that the
skin effect of alternating current causes the main heating
current to concentrate near the inner wall of the tubular
element.
426-31. Insulating Rating.
(a) The electrical insulation of the inner conductor shall
have a temperature rating greater than the operating temperature
of the cable for the specific system based on the designs and
tests of the manufacturer.
(b) The electrical insulation of the inner conductor shall
have a voltage rating at any point on the system higher than the
operating voltage at that point.
(c) The outer conductor (tubular element) shall not require
electrical insulation provided its outer surface is effectively
grounded at one or more locations. •
424-85: Accept
CMP 10
SUBMI1-TER: Kenneth W. Cohen, Aerco International, Inc.
42 Revise as follows:
~ o s e
boilers designed such that fault currents do not
pass through the presssure vessel and the pressure vessel is
electrically isolated from the electrodes, all exposed
noncurrent carrying metal parts including the pressure vessel,
supply and return connecting piping shall be grounded in
accordance with Article 250.
For all other designs the pressure vessel containing the
electrodes shall be-isolated and electrically insulated fr~n
ground.
SUBSTANTIATION: Aerco International, Inc. presently
manufactures an electrode Hot Water Boiler that is U.L. listed
(U.L. File #E-39417)
I have enclosed a pictoral representation of same.
We believe the grounding requirement, Para. 424-85 of the 1978
NEC is designed to cover those boilers where fault currents can
flow to neutral. However, the code '~oes not specifically
address our design, where fault currents cannot flow to ground
183
wiring, leads, temperature controllers, safety signs, junction
boxes, raceways and f i t t i n g s .
Resistance Heating Element. A specific separate element to
generate heat which is embedded in or fastened to the surface to
be heated.
(FPN) Tubular heaters, strip heaters, heating cable, heating
tape, heating panels, are examples of resistance heaters.
Impedance Heating System. A system in which heat is generated
in a pipe or rod, or combination of pipes and rods, by causing
current to flow through the pipe or rod by direct connection to
an ac voltage source from a dual-winding transformer, The pipe
or rod shall be permitted to be embedded in the surface to be
heated, or constitute the exposed components to be heated.
Skin Effect Heating System. A system in which heat is
generated on the inner surface of a ferromagnetic envelope
embedded in or fastened to the surface to be heated.
(FPN) Typically, an electrically insulated conductor is
routed through and connected to the envelope at the other end.
The envelope and the electrically insulated conductor are
connected to an ac voltage source from a dual-winding
transformer.
426-3. Application of Other Articles. All requirements of this
Code shall apply except as specifically amended in this
article. Fixed outdoor electric de-icing and snow-melting
equipment for use in hazardous (classified) locations shal~
comply with Articles 500 through 516.
426-4. Branch-Circuit Requirements. The ampacity of
branch-circuit conductors and size of overcurrent protective
devices supplying fixed outdoor electric de-iclng and
snow-melting equipment shall be calculated on the basis of 125
peEcent of the total load of the heaters. Fixed outdoor
electric de-icing and snow-melting installations shall be
permitted to be supplied by 15-, 20-, 25-, 30-, 40-, or
50-ampere circuits i f the circuit suppliesno other load.
Exception: An individual branch ciKcuit shall be permitted to
supply any load to a single heating unit.
426-32. Single Cable. A single cable may be used as the
internal return conductor i f the provisions of Section 426-31(a)
are met.
426-33. Pull Boxes. Pull boxes for the inner cable shall be
accessible without excavation by being placed in suitable vaults
or on above grade structure.
426-34. Branch-Circuit Requirements. The branch-circuit
supplying a skin effect current tracing system shall not be
limited in current rating by Section 426-3, but shall meet all
other applicable branch-circuit requirements of this Code.
426-35. AboveGround Installations. Skin effect current
tracing systems may be installed in exposed locations, such as
on substation and bridge structures to prevent failing ice
provided t~e heating element is grounded at the power feed
location ahd at the termination of the circuit.
SUBSTANTIATION: Skin effect current tracing has been used with
great success in Japan for snow melting on garage ramps, airport
aprons, and electrical substation structures. The principle of
operation is explained in literature attached to our proposed
amendment to Article 427.
This method is especially suitable for heating concrete slabs
because the heavy wall steel 'heating elements has the same
noncorroding characteristic in concrete that steel reinforcing
rod has and is also of adequate strength to be unaffected by
shrinkage or settlement of cracks. I t hasthe unique advantage
that the inner cable can be replaced and f u l l function restored
without breaking up the slab i f any maintenance problem ever
occurs. The main heating element, being of fully welded heavy
wall construction, is not subject to failure in service unless
there is catastrophic breakage of the slab. The thermal and
electrical characteristics of the system are such that several
thousand square feet can be heated with 100 watts per square
foot frem a single circuit.
A skin effect current tracing heat element, having roughly the
same dimensions as rigid conduit, can be installed without
mechanical protection in exposed locations and can be useful for
the accumulation of ice build up above transformer bushings,
walkways, or other places troubled by falling ice.
The purpose of each amended paragraph is explained here:
426-31(a). In most cases i t is possible to operate code rated
cables at higher currents in skin effect heating systems than
permitted by Table 310-16 without exceeding the temperature
rating of the cable as given in Table 310-16. Normal code
ampacity i s based on three conductors in a conduit and with the
thought that heat loss from the conduit might by limited by
enclosure within an insulated stud wall, for example. In a skin
effect tracing syste~l, one cable, not three, is producing heat.
More importantly, the temperature of the raceway is known and
bears a definite relationship to the pipeline temperature and
the overall thermal parameters of the system. Since cable
temperature and not current is the true basis of any rating, i t
is possible to design with higher currents when all facts are
known; a wide margin for error is thus unnecessary.
426-31(c). Section 310-2 states "Conductors shall be
insulated." The heat tube of a skin effect system is in truth
insulated by electremagnetic properties; under normal or Yault
conditions the outer surface is always isolated (insulated) from
the circuit voltage. But in every other application the Code
thinks in terms of circuit theory rather than wave theory. In
order to avoid possible misunderstandings, this paragraph is
included. The presence of a ground assures the absence of
voltage. There are technical approaches to this specific
situation that are somewhatmore definitive, but are f e l t
inappropriate fdr the NEC.
426-32. Section 300-20 requires that "all phase wires be
grouped" when in a metal raceway "to avoid heating the
surrounding metal by induction." The usual situation this
section prohibits is obviously hazardous, for very high
uncontrolled temperatures are possible. A skin effect tracing
system requires a single conductor in a metal tube specifically
to create heat in the tube; although not s t r i c t l y by induction.
This is permissible because the temperature of the system in
known, and is part of the design.
426-33. Self explanatory.
426-34. Self explanatory.
426-35. Skin effect current tracing heat elements are always of
steel and typically are from 3/4 inch to 2 inches in O.D. and
with a wall thickness greater than 0.100 inches~ They thus do
not require protection from mechanical abuse in most instances.
A single ground will assure that no potential can occur on the
heating element under normal or fault conditions; a second
round is simply a conservative redundancy.
ANEL RECOMMENDATION: Accept as Revised.
B.
426-10. General. Equipment for outdoor electric de-icing and
snow melting shill be identified as being suitable for:
l ) I the chemical, thermal and physical environment; and
installation in accordance with the manufacturer's
drawings and instructions.
426-11. Use. Electrical heating equipment shall be installed
in such a manner as to be afforded protection from physical
damage.
426-12..Thermal Protection. External surfaces of outdoor
electric de-lcing and snow-melting equipment which operate at
surface temperatures"exceedihg 60°C (140°F) shall be physically .
guarded, isolated, or thermally insulated to protect against
contact by personnel in the area.
426-13. Identification. The presence of outdoor electric
de-icing and snow-melting equipment shall be evident by the
posting of appropriate caution signs or markings where clearly
visible.
426-14. Special Permission. Fixed outdoor de-lcing and
snow-melting equipment employing methods of construction or
installation other than covered by this article may be used only
by special permission.
C. Resistance Heating Elements
426-20. EmbeddedDe-icing and Snow-Melting Equipment.
(a) Watt Density. Panels or units shall not exceed 120 watts
per square foot of heated area.
(b) Spacing. The spacing between adjacent cable runs is .
dependent upon the rating of the cable, and shall be not less
than one inch on centers.
(c) Cover. Units, panels or cables shall be Installed:
(I) On a substantial asphalt or masonry base at least 2
inches thick and have at least I-1/2 inches of asphalt or
masonry applied over the units, panels or cables; or
(2) They shall be permitted to be installed over other
approved bases and embedded within 3-I/2 inches of masonry or
'asphalt but not less than 1-1/2 inches from the top surface; or
(3) Equipment that has been specially investigated for other
forms of installation shall be installed only in the manner for
which i t has been investigated.
(d) Secured. Cables, units and panels shall be secured in
place by frames or spreaders or other approved means while the
masonry or asphalt finish is applied.
(e) Expansion and Contraction. Cables, units, and panels
shall not be installed where they bridge expansion Joints unless
adequately protected from expansion and contraction.
426-21. ExposedDe-Icing and Snow-Melting Equipment. (a) Secured. Heating element assemblies shall be secured to
surface being heated by approved means.
th~b)' Overtemperature. Wherethe heating element is not in
direct contact with the surface being heated, the design of the
heater assembly shall be such that its te~q~erature limitations
shall not be exceeded.
(c) Expansion and Contraction. Heating elements and
assemblies shall not be Installed where they bridge expansion
joints unless provision is made for expansion and contraction.
(d) Flexural Capability. Where installed on flexible
structureS, the heating elements and assemblies shall have a
flexural capability compatible with the structure.
~
ARTICLE 426-FIXED OUTDOORELECTRIC DE-ICING
AND SNOW-MELTING EQUIPMENT
A.
Installation
General
426-I. Scope. The requirements of this article shall apply to
electrically energized heating systems and the installation of
these systems;
(a) Embedded in driveways, walks, steps and other areas.
(b) Exposed on drainage systems, bridge structures, roofs and
other structures.
426-2. Definitions. For the purpose of this article:
Heating System. A complete system consisting of components
such as heating elements, fastening devices, nonheating circuit
184
426-22. Installation of Nonheating Leads for Embedded Equipment.
(a) Grounding Sheath or Braid. Nonheating leads having a
grounding sheath or braid shall be permitted to be embedded in
the masonry or asphalt in the same manner as the heating cable
without additional mechanical protection.
(b) Raceways. All but one to 6 inches of nonheating leads of
Type TW and other approved types not having a ground!ng sheath
shall be enclosed in a rigid conduit, electrical metallic
tubing~ intermediate metal conduit, or other raceways within
asphalt or masonry; and the distance from the factorysplice to
raceway shall be not less than one inch or more than 6 inches.
(c) Bushings. Insulating bushings shall be used in the
asphalt or masonry where leads enter conduit or tubing.
(d) Expansion and Contraction. Leads shall be protected in
expansion Joints and where they emerge from masonry or asphalt
by rigid conduit, electrical metallic tubing, intermediate metal
conduit, other raceways, or other approved means.
(el Leads in Junction Boxes. Not less than 6 inches of free
nonheating lead shall be within the junction box.
426-23. Installation of Nonheating Leads for Exposed Equipment.
(a) Nonheating Leads. Power supply nonheating leads (cold
leads) for resistance elements shall be suitable for the
temperature encountered. Preassembled nonheating leads on
approved heaters shall be permitted to be shortened i f the
markings specified in Section 426-25 are retained. Not less
than 6 inches of nonheating leads shall be provided within the
junction box.
(b) Protection. Nonheating power supply leads shall be
enclosed in a rigid conduit, intermediate metal conduit,
electrical metellic tubing, or other approved means.
426-24. Electrical Connection.
(a) Heating Element Connections. Electrical connections,
other than factory connections of heating elements to nonheating
elements embedded in masonry or asphalt or on exposed surfaces,
shall be made with insulated connectors identified for the use.
(b) Circuit Connections. Splices and terminations at the end
of the nonheating leads, other than the heating element end,
shall be installed in a box or f i t t i n g i6 accordance with
Sections 110-14 and 300-15.
426-25. Marking. Each factory-assembled heating unit shall be
legibly marked within 3 inches of each end of the nonheating
leads with the permanent identification symbol, catalog number,
and ratings in volts and watts, or in volts and amperes.
426-26. Corrosion Protection. Ferrous or nonferrous metal
raceways, cable armor, cable sheaths, boxes, f i t t i n g s , supports
and support hardware shall be permitted to be installed i n
concrete or in direct contact with the earth, or in areas
subject to severe corrosive influences, when made of material
suitable for the condition, or when provided with corrosion
protection identified as suitable for the condition.
426-27. Grounding.
(a) Metal Parts. Exposednoncurrent-carrying metal parts of
equipment l i k e l y to become energized shall be grounded as
required in Article 250.
(b) Grounding Braid or Sheath. Grounding mebns, such as
copper braid, metal sheath, or other approved means, shall be
provided as part of the heated section of the cable, panel, or
unit.
(c) Bonding and Grounding. All noncurrent-carrying metal
parts that are l i k e l y to become energized shall be bonded
together and connected to an equipment grounding conductor sized
in accordance with Table 250-95, extending to the distribution
panelb~ard.
D. Impedance Heating
or nonferrous metal raceways, boxes, f i t t i n g s , supports and
support hardware shall be permitted to be installed in concrete
or in direct contact with the earth, or in areas subjected to
'severe corrosive influences, where made of material sultable for
the condition, or where provided with corrosion protection
identified as suitable for the condition. Corrosion protection
shall maintain the original wall thickness of the ferromagnetic
envelope.
426-44. Grounding. The ferromagnetic envelope shall be
grounded at both ends; and, in addition, i t shall be permitted
to be grounded at intermediate points as required by its design.
The provisions of Section 250-26 shall not apply to the
installation of skin effect heating systems.
(FPN) See Section 250-26(d).
F. Control and Protection
426-50. Disconnecting Means. All fixed outdoor de-icing and
snow-melting equipment shall be provided with a means for
disconnection from all ungrounded conductors. Where readily
accessible to the user of the equipment, the branch-circuit
switch or circuit breaker shall be permitted to serve as the
disconnecting means. Switches used as the disconnecting means
shall be of,the indicating type.
426-51. Controllers.
(a) Temperature Controller With "Off" Position. Temperature
controlled switching devices which indicate an "off" position
and which interrupt line current shall open all ungrounded
conductors when the control device is in.the "off" position.
These devices shall not be permitted to serve as the
disconnecting means unless provided with a positive lockout in
the "off" position.
(b) Temperature Controller Without "Off" Position.
Temperature controlled switching devices which do not have an
"off" position shall not be required t6 open all ungrounded
conductors and shall not be permitted to serve as the
disconnecting means.
(c) Remote Temperature Controller. Remote controlled
temperature actuated devices shall not be required to meet the
requirements of Section 426-51(a). These devices shall not be
permitted to serve as the disconnecting means.
(d) Combined Switching Devices. Switching devices consisting
of combined temperature actuated devices and manually controlled
switches which serve both as the controller and the
disconnecting means shall comply with all of the following
conditions:
(1) Open all ungrounded conductors when manually placed in
the "off" position; and
(2) be "so designed that the circuit cannot be energized
automatically i f the device has been manually placed in the
"off" position; and
(3) be provided with a positive lockout in the "off"
position.
426-52. Overcurrent Protection. Fixed outdoor electric
de-icing and snow-melting equipment shall be considered as
protected against overcurrent where supplied by one of the
branch circuits as specified in Section 426-4.
PANEL C(}~MENT: Article 426 has been completely revised and
augmented by CMP 10. CMP 10 feels that these revisions improve
'and c l a r i f y present Article 426 and incorporates the intent of
this proposal.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
COMMENTON VOTE:
ERICKSON: Although I agree with the panel action on this
proposal I would like to comment on certain sections.
Section 426-4: Changef i r s t sentence to read "The ampacity of
branch-circuit, conductors supplying fixed outdoor electric
de-icing and snow-melting equipment shall be in accordance with
Section 310-15. The rating or setting of overcurrent protective
devices shall be in accordance with Section 240-3, Exception No.
I and Section 210-22(c) where applicable.
See Explanation for
Vote on Proposal No. 19.
426-30. Personnel Protection. Exposedelements of impedance
heating systems shall be physically guarded, isolated, or
thermally insulated with weatherproof jacket to protect against
contact by personnel in the area.
426-31. Voltage Limitations. The impedance heated elements
shall not operate at a voltage greater than 30 volts ac.
Exception: The voltage shall be permitted to be greater than
30 volts, but not more than 80 volts, i f a ground-fault
circuit-interrupter for personnel protection is provided.
426-32. Isolation Transformer. A dual-winding transformer with
a grounded shield between the primary and secondary windings
shall be used to isolate the distribution system from the
heating system.
426-33. Induced Currents/ All current-carrying components
shall be installed in accordance with Section 300-20.
426-34. ~Grounding. An impedance,heating system that is
operating at a voltage greater than 30, but not more than 80,
shall be grounded at designated point(s).
Section 426-31, Exception: The use of the Words "for personnel
protection" although not defined by the NEC, may imply to
inspectors a 5 n~ device. These devices would be inoperative on
an impedance heating circuit since there is more leakage current
than 5 mA. What is intended is a GFCI as defined by the NEC
which would operate at a lower current to ground than the
circuit protective device. I recommend those words be deleted.
See Section 680-41(a) for a precedent.
JORDAN: The following co~mnents are editorial:
i . I t is suggested that the f i r s t sentence of Section 426-4 be
revised to conform with Proposal No. 19 to assure consistency.
2. In Section 426-10(2): Change the word "installation" to
',,installed. u
3. InSection 426-12: Third line; delete word "surface," which
is redundant.
4. In Section 426-14: In 3rd line change "may" to "shall."
5. In Section 426-22(a): Last line; change word "mechanical"
to "physical," to conform to code nomenclature.
6. The word "approved" is used 5 or 6 times and should be
scrutinized to assure conformance with the technical subcommittee's findings on "approved for the purpose:"
E. Skin Effect Heating
426-40. Conductor Ampacity. The ampacity of the electrically
insulated conductor inside the ferromagnetic envelope shall be
permitted to exceed the values shown in. Article 310, provided i t
is identified as suitable for this use.
426-41. Pull Boxes. Where pull boxes are used they shall be
accessible without excavation by location in suitable vaults or
above grade. Outdoor pull boxes shall be of watertight
construction.
426-42. Single Conductor in Enclosure." The provisions of
Section 300-20 shall not apply to the installation of a single
conductor in a ferromagnetic envelope (metal enclosure).
426-43. Corrosion Protection. Ferremagnetic envelopes, ferrous
185
b
(d) Flexural Capability. Where installed on flexible
pipelines, the heating elements and assemblies shall have a
flexural capability compatible with the pipeline.
(el PowerSupply Leads• Powersupply nonbeating leads (cold
leads) for resistance elements shall be suitable for the
temperature encountered. Preassemblednonheating leads on
approved heaters may be shortened i f the markings specified in
Section 427-24 are retained. Not less than 6 inches of
nonheating leads shall be provided with the junction box.
(f) PowerSupply Leads Protection. Nonheating power supply
leads shall be protected where they emerge from electrically
heated pipeline or vessel heating units by raceway•
(g) Interconnecting Leads. Interconnecting nonheating leads
connecting portions of the heatlng system shall be permitted to
be covered by thermal insulation'in the samemanner as the
heaters.
427-15. ImpedanceHeating.
(a) Personnel Protection. All accessible external surfaces
of the pipeline and vessel being heated shall be physically
guarded, isolated, or thermally insulated (with weatherproof
jacket for outside installations) to protect against contact by
personnel in the area.
(b) Voltage Limitations. The pipeline or vessel being heated
and electrical connections to i t shall not operate at a voltage
greater than 30 volts AC. Exception No. 1: The voltage may be
greater than 30 volts but not more than 80 volts i f ground-fault
sensing device with interrupting capability for personnel
protection is provided.
(c). Grounding. The pipeline and/or vessel being heated which
is operating at a voltage greater than 30 but not more than 80
shall be grounded at one designated point.
(d) Induced Currents. All current-carrying components shall
installed in accordance with Section 300-20.
be(el Isolation Transformer. A dual-winding transformer wi~h'a
grounded shield between the primary and secondary shall be used
to isolate the distribution system from the heating system.
427-16. Induction Heating. This section covers the
installation of line frequency induction heating equipment and
accessories for pipelines and vessels. See Articl~ 665 for
other applications•
(a) Personnel Protection. Induction coils and electrical
connections to them which operate or may'operate at a voltage
greater than 30 volts AC shall be enclosed in a raceway,
nonmetallic or split metallic enclosure, isolated or made
weatherproof by locatioo to protect personnel in the area.
(b) Induced Current. Induction coils shall be prevented from
inducing circulating currents in surrounding metallic equipment,
supports or structures by shielding, isolation or insulation of
the current paths. All possible stray current paths shall be
bonded to prevent arcing.
427-17. Skin Effect Heating.
(a) Grounding. The ferromagnetic envelope shall be grounded
at both ends. The ferromagnetic envelope shall also be
permitted to be grounded at intermediate points as required by
its design.
(b) Conductor Ampacity. The ampacity of the
electrically-lnsulated conductor inside the envelope shall not
exceed the rating for which i t was designed, rated and tested.
(c) Pull Boxes. P~ll boxes for pulling the
electrically-insulated conductor in the ferromagnetic envelope
shall be permitted to be buried under the thermal insulation
providing their locations are indicated by permanent markings on
the insulation Jacket surface and on drawings. For outdoor
installations pull boxes are to be of watertight construction.
(d) Single Conductor in Enclosure. Section 300-20 shall be
waived to allow installation of a single conductor in a
ferromagnetic envelope (metal enclosure).
ARTICLE 427 -- FIXED ELECTRIC HEATINGEQUIPMENT FOR
PIPELINES AND VESSELS
Article 427: Accept
CMP 10
Secretary's Note: I t was the action of the Correlating
Conwnittee that further consideration be given to the comments
expressed in the voting.
SUBMITTER: TSC-Skin Effect Current Tracing
47 Revise as follows:
ARTICLE 427-F.IXED ELECTRIC HEATINGEQUIPMENTFOR
PIPELINES AND VESSELS
A.
General
427-I. Scope. The requirements of this article shall apply to
electrically energized heating systems and the installation of
these systems used with pipeline and/or vessels.
427-2. Definitions. For the purpose of this article:
(a) Pipeline: A pipeline is a length of pipe including pumps,
valves, flanges, control devices, strainers and/or similar
equip~nt for conveying fluids.
(b) Vessel: A vessel is a container such as a barrel, drum or
tank for holding fluids or other material.
(c) Integrated Heating System: An integrated heating system
is a complete system consisting of components such as pipelines,
vessels, heating elements, heat transfer medium, thermal
insulation, moisture barrier, nonheating leads, temperature
controllers, safety signs, junction boxes, raceways and f i t t i n g s .
(d) Resistance Heating Element: A resistance heating element
is a specific separate element to generate heat which is applied
to the pipeline or vessel externally or internally. Tubular
heaters, strip heaters, heating cable, heating tape, heating
blankets, immersion heaters, etc. are examples of resistance
• heaters.
(el ImpedanceHeating System: An impedance heating system is
a system in which heat is generated in a pipeline or vessel wall
by causing current to flow through the pipeline or vessel wall
by direct connection to an AC voltage source from a dual winding
transformer.
(f) Induction Heating System: An induction heating system is
a system in which heat is generated in a pipeline or vessel wall
by inducing current and hysterlsis effect in the pipeline or
vessel wall from an external isolated AC field source.
(g) Skin Effect Heating System: A skin effect heating system
is a system in which heat is generated on the inner surface of a
ferromagnetic envelope attached to a pipeline and/or vessel. An
electrically insulated conductor is routed through and connected
to the envelope at the far end. The envelope and the
electrically insulated conductor are connected to an AC voltage
source from a dual-wlnding transformer.
427-3. Application of Other Articles. All requirements of this
Code shall apply' except as specifically amended in this
article. Cord-connectedpipe heating assemblies intended for
specific uses and approved for the purpose shall be installed
according to Article 422. Fixed electric pipeline and vessel
heating equipment for use in hazardous locations shall comply
with Articles 500 through 516.\
427-4. Branch-Circuit Requirements. The minimum size of
branch-clrcuit conductors and overcurrent protective devices
supplying f i x e d e l e c t r i c pipeline and vessel heating equipment
shall be calculated on the basis of 125 percent of the total
load of the heaters.
B.
Installatlon
427-10. General.
(a) Equipment Type and Installation Requirements. Equipment
for pipeline and vessel electrical heating shall be (1) of a
type compatible with the chemical, thermal and physical
environment; and (2) installed in accordance with the
manufacturer's drawings and installation instructions.
(b) Equipment Design. Equipment for pipeline and vessel
electrical heating shall be used within the limits for which i t
has been designed.
427-11. Use. Electrical heating equipment shall be installed
in such a manner as to be afforded protection from physical
damage.
427-12. Thermal protection. Accessible external surfaces of
pipeline and vessel heating equipment which operate at surface
temperatures exceeding 60°C (140°F) shall be physically guarded,
isolated, or thermally insulated to protect against contact by
personnel in the area.
427-13. Identification. The presence of electrically heated
pipelines and/or vessels shall be evident by the posting of
appropriate caution signs or markings at frequent intervals
along the pipeline or vessel.
427-14. Resistance Heating Elements.
(a) Secured. Heating element assemblies shall be secured to
the surface being heated by means other than the thermal
insulation.
(b) Not in Direct Contact. Where the heating element is not
in direct contact with the pipeline or vessel being heated,
means shall be proClded to prevent overtemperature of the
heating element unless the design of the heater assembly is such
that its temperature limitations will not be exceeded.
(c) Expansion and Contraction. Heating elements and
assemblies-shall not be installed where they bridge expansion
joints unless provision is made for expansion ~nd contraction.
C. Construction and Protection
427-20. Disconnecting Means.
(a) Switch or Circuit Breaker. Meansshall be provided to
disconnect all fixed electric pipeline or vessel heating
equipment from all ungrounded conductors. The branch-circuit
switch or circuit breaker, where readily accessible to the user
of the equipment, shall be permitted to serve as the
disconnecting means. Switches used as disconnecting means shall
be of the indicating type, and shall be provided with a positive
lockout in the "off" position.
(b) Cord-ConnectedEquipment. The factory-installed
attachment plug of cord-connected equipment rated 20 amp or less
and 150 volts or less to ground is an acceptable means of
disconnection.
427-21. Controls.
(a) TemperatureControl with "off" Position.t Temperature
controlled switching devices which indicate an "off" position
and which interrupt line current shall open all ungrounded
conductors when the control device is in this "off" position.
These devices shall not serve as a disconnecting means unless
provided with a positive lockout in the "off" position.
(b) TemperatureControl without "off" Position. Temperature
controlled switching devices which do not have an "off" position
are not required to open all ungrounded conductors and shall not
serve as a disconnecting means.
(c) RemoteTemperature Control. Remotecontrolled
ter~oerature actuated devices shall not be required t o meet the
requirements of Section 427-21 (a) and (b) above. Thesedevices
shall not serve as a disconnecting means•
186
(d) CombinedDevices. Switching devices consisting of
combined temperature actuated devices and manually controlled
switches which serve both as controllers and disconnecting means
shall: (1) Open all ungrounded conductors when manually placed
in the "off" position, and (2) be so designed that the circuit
cannot be energized automatically i f the device has been
manually placed in the "off" position, and (3) be provided with
a positive lockout in the "off" position.
427-22. Overcurrent Protection. Heating equip~nt shall be
protected against overcurrent in accordance with Section 210-20.
427-24. Markings. Each factory-assembled heating unit shall be
legibly marked within 3 inches of the end of each power supply
nonheating lead with the permanent identification symbol,
catalog number, and ratings in volts and watts, or in volts and
amperes.
427-25. Electrical Connections.
(a) Nonheating Interconnections. Nonheating
interconnections, where required under thermal insulation, shall
be made with properly installed insulated connectors approved
for the purpose.
(b) Splice Connections and Terminations. Splice connections
and terminations outside the thermal insulation shall be
installed in a box or f i t t i n g in accordance with Sections 110-14
and 300-15.
427-26. Grounding. Exposednoncurrent-carrying metal parts of
electric heating equipment which are likely to become energized
shall be grounded as required in Article 250.
427-30. General. Induction and skin effect heating systems may
be operated at voltages over 600 volts. Requirements for
circuits and equipment operating at over 600 volts, nominal, are
in Article 710.
SUBSTANTIATION: We are completing the scope of the relatively
new Article 427 which at the present only covers resistance
heating, by adding impedance heating, induction heating and skin
effect current tracing.
PANEL RECOMMENDATION: Accept as Revised:
427-II. Use. E1ectrlcal heating equipment shall be installed
In such a manner as to be afforded protection from physical
damage.
427-12. Thermal Protection. External surfaces of pipeline and
vessel heating equipment which operate at surface temperatures
exceeding 60°C (140°F) shall be physically guarded, isolated, or
thermally insulated to protect against contact by personnel in
the area.
427-13. Identification. The presence of electrically heated
pipelines and/or vessels shall be evident by the posting of
appropriate caution signs or markings at frequent intervals
along the pipeline or vessel.
C.
ARTICLE 427-FIXED ELECTRIC HEATINGEQUIPMENTFOR
PIPELINES AND VESSELS
A.
General
427-1. Scope. The requirements of this article shall apply to
electrically energized heating systems and the installation of
these systems used with pipelines and/or vessels.
427-2. Definitions. For the purpose of this article:
Pipeline. A length of pipe including pumps, valves, flanges,
control devices, strainers and/or similar equipment for
conveying fluids.
Vessel. A container such as a barrel, drum or tank for holding
fluids or other material.
Integrated Heating System. A complete system consisting of
components such as pipelines, vessels, heating elements, heat
transfer medium, thermal insulatlon, moisture barrier,
nonheating leads, temperature controllers, safety signs~
junction boxes, raceways and f i t t i n g s .
Resistance Heating Element. A specific separate element to
generate heat which is applied to the pipeline or vessel
externally or internally.
(FPN) Tubular heaters, strip heaters, heating cable, heating
tape, heating blankets, immersion heaters are examples of
resistance heaters.
Impedance Heating System. A system in which heat is generated
in a pipeline or vessel wall by causing current to flow through
the pipeline or vessel wall by direct connection to an ac
voltage source from a dual-winding transformer.
Induction Heating System. A system in which heat is generated
in a pipeline or vessel wall by inducing current and hysteresis
effect in the pipeline or vessel wall from an external isolated
ac field source.
Skin Effect Heating System. A system in which heat is
generated on the inner surface o f a ferromagnetic envelope
attached to a pipeline and/or vessel.
(FPN) Typically, an electrically insulated conductor is
routed through and connected to the envelope at the other end.
The envelope and the electrically insulated conductor are
connected to an ac voltage source from a dual-winding
transformer.
427-3. Application of Other Articles. All requirements of this
Code shall apply except as specifically amended in this
article. Cord-connected pipe heating assemblies intended for
specific use and identified as suitable for this use shall be
installed according to Article 422. Fixed electric pipeline and
vessel heating equipment for use in hazardous (classified)
J
locations shall comply with Articles 500 through 516.
427-4. Branch-Circuit Requirements. The ampacity of
branch-circuit conductors and size of overcurrent protective
devices supplying fixed electric pipeline and vessel heating
equipment shall be calculated on the basis of 125 percent of the
total load of the heaters.
B.
Resistance Heating Elements.
427-14. Secured. Heating element assen~)lles shall be secured
to the surface being heated by means other than the thermal
insulation.
427-15. Not in Direct Contact. Where the heating element is
not in direct contact with the pipeline or vessel belng heated,
means shall be provided to prevent overtemperature of the
heating element unless the design of the heater assembly is such
that its temperature limitations will not be exceeded.
427-16. Expansion and Contraction. Heating elements and
assemblies shall not be installed where they bridge expansion
Joints unless provision is made for expansion and contraction.
427-17. Flexural Capability. Where installed on flexible
pipelines, the heating elements and assemblies shall have a,
flexural capability compatible with the pipeline.
427-18. Power Supply Leads.
(a) Nonheating Leads. Power supply nonheating leads {cold
leads) for resistance elements shall be suitable for the
temperature encountered. Preassembled nonheatlng lead) on
approved heaters may be shortened if the markings specified in
Section 427-20 are retained. Not less than 6 inches of
nonheatlng leads shall be provided within the Junction box.
(b) Power Supply Leads Protection. Nonheatlng power supply
leads shall be protected where they emerge from electrically
heated pipeline or vessel heating units by rigid metal conduit,
intermediate metal conduit, electrical metallic tubing, or other
raceways identified as suitable for the application.
{c) Interconnecting Leads. Interconnecting nonheatlng leads
connecting portions of the heating system shall be permitted to
be covered by thermal insulation in the samemanner as the
heaters.
427-19. Electrical Connections.
(a) Nonheating Interconne~tions. Nonheating
interconnections, where required under thermal insulation, shall
be made with insulated connectors identified as suitable for
this use.
(b) Circuit Connections . Splices and terminations outside
the thermal insulation shall be installed in a box or f i t t i n g in
accordance with Sections 110-14 and 300-15.
427-20. Marking. Each factory-assembled heating unit shall be
legibly marked within 3 inches of each end of the nonheating
leads with the permanent identification symbol, catalog number,
and ratings in volts and watts, or in volts and amperes.
427-26. Grounding. Exposednoncurrent-carrying metal parts of
electric heating equipment which are likely to beceme energized
shall be grounded as required in Article 250.
D.
Impedance'Heating
427-25. Personnel Protection. All accessible external surfaces
of the pipeline and/or vessel being heated shall be physically
guarded, isolated, or thermally insulated (with weatherproof
jacket for outside installations) to protect against contact by
personnel in the area.
427-26. Voltage~imitations. The pipeline or vessel being
heated shall not operate at a voltage greater than 30 volts ac.
Exception : The voltage shall be permitted to be greater than
30 volts but not more than 80 volts i f a ground-fault
circult-interrupter for personnel protection is provided.
427-27. Isolation Transformer. A dual-winding transformer with
a grounded shield between the primary and secondary windings
shall be used to isolate the distribution system from the
heating system.
427-28. Induced Currents. All current-carrying components
shall be installed in accordance with Section 300-20.
427-29. Grounding. T~hepipeline and/or vessel being heated
which is operating at a voltage greater than 30 but not more
than 80 shall be grounded at one designated point.
~--
E.
Induction Heating
427-35. Scope. This part covers the installation of line
frequency induction heating equipment and accessories for
pipelines and vessels.
(FPN) See Article 665 for other applications.
427-36. Personnel Protection. Induction coils that operate or
may operate at a voltage greater than 30 volts ac shall be
enclosed in a nonmetallic or split metallic enclosure, isolated
or made inaccessible by location to protect personnel in the
area.
427-37. Induced Current. Induction coils shall be prevented
from inducing circulating currents in surrounding metallic
equipment, supports or structures by shielding, isolation or
Installation
427-10. General. Equipment for pipeline and vessel electrical
heating shall be identified as being suitable.for:
(1) the chemical, thermal and physical environment; and
(2) installation in accordance with the manufacturer's
drawings and instructions.
187
I. In Section 427-4: Changewording to conform with Proposal
No. 19, to assure consistency.
2. In Section 427-12: Second sentence; delete word "surface,"
which is redundant.
3. In Section 427-16: Third line; make "provision" plural and
change verb "is" to "are."
4. In Section 427-56(c): First sentence, third line: Change
"(b) above" to read "Section 427-55(b)."
insulation of the current paths. Stray current paths shall be
bonded to prevent arcing.
F.
Skin Effect Heating
427-45. Conductor Ampacity. The ampacity of the
electrically-insulated conductor inside the ferromagnetic
envelope shall be permitted to exceed the values given in
Article 310 provided i t is identified as suitable for this use.
427-46. Pull Boxes. Pull boxes for pulling the electrically
insulated conductor in the ferromagnetic envelope shall be
permitted to be buried under the thermal insulation providing
their locations are indicated by permanent markings on the
insulation jacket surface and on drawings. For outdoor
installations, pull boxes are to be of watertight construction.
427-47. Single Conductor in Enclosure. The provisions of
Section 300-20 shall not apply to the installation of a single
conductor in a ferromagnetic envelope (metal enclosure).
Ca) Grounding. The ferromagnetic envelope shall be grounded
at both ends and, in addition, i t shall be permitted to be
grounded at intermediate points as required by its design.
Ferromagnetic envelope shall be bonded at all joints to assure
electrical continuitx.
The provisions of Section 250-26 shall not apply to the
installation of skin effect heating systems.
(FPN) See Section 250-26(d).
427-I (HOD 1978 NEC): Reject
CMP 10
SUBMII'TER: Manufacturing Chemists Association
48 Delete the second sentence of 427-1.
~'I]B'S'~'A~rIATION: There is a need'for recognition of all types of
electrical heating in common use today in industry.
There are five methods of electrical heating: (i) impedance
heating-current flow through the pipeline or vessel wall as an
impedance; (2) induction heating-current induced into the pipe
by induction; (3) skin effect-current flow confined by skin
effect to the inner wall of a tubular steel element welded to or
inside the pipeline; (4) external heating with a heating, cable,
heating tape, strip heaters, tubular heaters, heating blankets,
etc.; IS) internal heating with a heating cable, tubular
heaters, immersion heaters, etc., or by electrically-powered
circulating heaters.
The f i f t h line of 427-1 specifically excludes two types of
electrical heating. These should be recognized.
PANEL RECOMMENDATION:- Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal. See
action on Proposal No. 47.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
G. Control and Protection
427-55. Disconnecting Means.
(a). Switch or Circuit Breaker. Means shall be provided to
disconnect all fixed electric pipelines or vessel heating
equipment from all ungrounded conductors. The branch-circuit
switch or circuit breaker, where readily accessible to the user
o f the equipment, shall be permitted to serve as the
disconnecting means. Switches used as disconnecting means shall
be of the indicating type, and shall be provided with a positive
lockout in the "off" position.
(b) Cord-and-Plug Connected Equipment. The factory-installed
attachment plug of cord- and plug-connected equipment rated.20
amperes or less and 150 volts or less to ground shall be
permitted to be the disconnecting means.
427-56. Controls.
(a) TemperatureControl with "Off" Position. Temperature
controlled switching devices which indicate an "off" position
and which interrupt llne current shall open all ungrounded
conductors when the control device is in this "off" position.
These devices shall not be permitted to serve as the
disconnecting means unless provided with a positive lockout in
the "off" position.
(b) TemperatureControl without "Off" Position. Temperature
controlled switching devices which do not have an "off" position
are not required to open all ungrounded conductors and shall not
be permitted to serve as the disconnecting means.
(c) RemoteTemperature Controller. Remotecontrolled
temperature actuated devices shall not be required to meet the
requiraments of Section 427-56(a) and (b) above. These devices
shall not be permitted to serve as the disconnecting means.
(d) Combined Switching Devices. Switching devices consisting
of combined temperature actuated devices and manually controlled
switches which serve both as the controllers and the
disconnecting means shall cemply with all the following
conditions:
(I) Open all ungrounded conductors when manually 'placed in the
"off" position; and
\
(2) be so designed that the circuit cannot be energized
automatically i f the device has been manually placed in the
"off" position; and
(3) be provided with a positive lockout in the "off" position.
427-57. Overcurrent Protection. Heating equipment shall be
considered as protected against overcurrent where supplied by a
branch circuit as specified in Section 427-4.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENT ON VOTE:
ERICKSON: Although I agree with panel action on this proposal
I would like to co~Tnent on certain sections.
427-I (HOD 1978 NEC): Reject
CMP 10
SUBMITTER: Pipeline Heating Systems, Brecksville, OH
49 Revise the ending of second sentence to read
a-a-fTe~-tI~e comma, "other than the impedance method."
SUBSTANTIATION: Sameas Proposal No. 62 to 1978 Preprint.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal. See
action on Proposal No. 47.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
427-3: Accept
CMP 10
SUBMITTER:" C1aude'E. Deering, Jr., American Petroleum Institute
PI~q~I~TAL-~.
• 50 Add the word "classified" in parenthesis after
~ w o r d "hazardous."
SUBSTANTIATION: I t is proposed that the word "~lqssified", in
parenthesis, be inserted after the word "hazardous." This is
consistent with Article 500, which is entitled "Hazardous
(Class!fied) Locations." The proposed wording recognizes that a
location is not hazardous per se, but is classifed depending o n
the properties of the flammable or combustible substance'which
may be present, and the likelihood that a flammable or
combustible concentration or quantity will be present.
PANEL RECOMMENDATION: Accept.
PANEL RECOMMENDATION: See Proposal No. 47.
~ON ~~ENDATION:
UnanimouslyAffirmative.
I
427-3: Accept
CMP ~I0
SUBMITTER: TSC-Approvedfor the Purpose
I~-0]~-0-~7~-~.• 51 See the Technical Subcommittee "Recommendations"
un-un-d-e-r-t-fle definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: See Proposal No; 47,
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Section 427-4: Changef i r s t sentence to read "The ampacity of
branch-circuit conductors supplying fixed electric pipeline and
vessel heating equipment shall be in accordance with Section
240-3, Exception No. I and Section 210-22(c) where applicable.
See Explanation for Vote on Proposal No. lg.
427-3: Reject
CMP 10
SUBMITTER: Warren H. Cook, IEEE
52 Changereference from Article 422 to Article 400.
SUBSTANTIATION: Article 422 deals with appliances while Article
~00 is flexible cords and cables.
PANEL RECOMMENDATION: Reject.
I~ANEL COMMENT: The present wording adequately reflects the
P a n e l ' s intent.
/
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Section 427-26, Exception: The use of the words "for personnel
protection" although not defined by the NEC, may imply to
inspectors a 5 n~ device. These devices would be inoperative on
an impedance heating circuit since there is mere leakage current
than 5 nu~. What is intended is a GFCI as defined by the NEC
which would operate at a lower current to ground than the
circuit protective device. I recommend those words be deleted.,
See Section 680-41(a) for a precedent.
427-4: Reject
CMP 10
SUBMITTER: Warren H. Cook, IEEE
PR~53
Revise427-4 to read:
~nimum
size of branch-circuit conductors supplying fixed
electric pipeline and vessel heating equipment shall be
calculated on the basis of 125 percent of the total load of the
heaters. The size of branch-circuit overcurrent protective
devices supplying fixed eIectric pipeline and vessel heating
Section 427-29: Delete "one" and add (S) at end of sentence to
agree with panel decision and Section 426-34.
Section 426-34(a): This should be renumbered 427-48 to agree
with panel decision and format established in Section 426-44."
JORDAN: The following comments are editorial:
188
equipment shall be calculated on the basis of 125 percent of the
total load current.
SUBSTANTIATION: The use of a minimum requirement for
overcurrent protection of branch-circuits could lead to ground
currents for extended periods of time. The panel was supplied
with a typical circuit of a pipe tracing circuit.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
COMMENTON VOTE:
ERICKSON: Although I agree with the panel action on this
specific proposal, I also agree with the intent of the
proposal. Mr. Cook desires to have minimum sized branch-circuit
overload protection to provide the best possible ground-fault
protection for resistance heating loads. See comments on
Proposal 47 for a suggested solution.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: See Proposal NO. 47.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
427 Part D-(New)(HOD 1978 NEC): Reject
CMP 10
SUBMITTER: Pipeline Heating Systems, Ind., Brecksville OH
58 Add a new Part D to Article 427 as follows:
D. Skin Effect Current Tracing
427-27. Scope. The provisions of Part D of this Article shall
apply to fixed pipeline heating systems utilizing a tubular
resistive heating element of ferromagnetic material and having
within the tubular element an electrically insulated return
conductor so arranged that the skin effect of alternating
current causes the main heating current to concentrate near the
inner wall of the tubular element.
427-28. Insulating Rating.
(a) The electrical insulation of the inner conductor shall
have a temperature rating greater than the operating temperature
of the cable for the specific system based on the designs and
tests of the manufacturer.
(b) The electrical insulation of the inner conductor shall
have a voltage rating at any point on the system higher than the
operating voltage at that point.
(c) The outer conductor (tubular element) shall not require
electrical insulation provided its outer surface is effectively
grounded at one or more locations.
427-29. Single Cable. A single cable may be used as the
internal return conductor i f the provisions of Section 427-28(a)
are met.
427-30. Pull Boxes.
(a) For above ground pipelines, pull boxes for the inner
cable may be covered by the pipeline thermal insulation provided
their locations are suitably indicated.
(b) For below ground pipelines, pull boxes for the inner
cable may be covered by the pipeline thermal insulation provided
they are of waterproof construction and their locations are
indicated on the pipeline drawings.
427-31. Grounding. Each tubular heating element shall be
grounded at the power feed point on the pipeline, and
additionally may be grounded at other locations.
SUBSTANTIATION: Skin effect current tracing was specifically
not included in the 1975 Code because there was insufficient
experience with such systems at the time the amendments were
closed. Such experience is now available.
Attached literature explains the principle of operation, which
has the remarkable property of allowing a heating current to
flow longitudinally through the Wall of a steel tube even though
the outer surface of the tube is at ground potential at all
points.
The prime advantage of the.system is the fact that technically
and economically i t is entirely feasible to have single circuits
up to seven or more miles in length, thus permitting tracing of
pipelines across rights-of-way, easements, bodies of water,
etc,, where power is not available. By its very nature the
system is safe, because all current carrying parts are at all
times f u l l y enclosed by grounded heavy wall steel raceways or
boxes.
The purpose of each amended paragraph is explained here:
427-1. Eliminates the exclusion of skin effect heating from
Article 427.
427-28(a). In most cases i t is possible to operate code rated
cables at higher currents in skin effect heating systems than
permitted by Table 310-16 without exceeding the temperature
rating of the cable as given in Table 310-16. Normal code
ampacities are based on three conductors in a conduit and with
the thought that heat loss from the conduit might be limited b y
enclosure within an insulated stud wall, for example. In a skin
effect tracing system, one cable, not three, is producing heat.
More importantly, the temperature of the raceway is known and
bears a definite relationship to the pipeline temperature and
the overall thermal parameters of the system. Since cable
temperature and not current is the true basis of any rating, lit
is possible to design with higher currents when all facts are
known; a wide margin for error is thus unnecessary.
427-28(c). Section 310-2 states "Conductors shall be
insulated." The heat tube of a skin effect system is in truth
insulated by electrical magnetic properties; under normal or
fault conditions the outer surface is always isolated
(insulated) from the circuit voltage. But , every other
application the Code thinks in terms of Circuit theory rather
than wave theory. In order to avoid possible misunderstandings,
this paragraph is included. The presence of a ground assures
the absence of voltage. There are technical approaches to this
special situation that are somewhatmore definitive, but are
f e l t inappropriate for the NEC.
427-29. Section 300-20 requires that "all phase wires be
grouped" when in a metal raceway "to avoid heating the
surrounding metal by induction." The usual situation this
section prohibits is obviously hazardous, for very high
uncontrolled temperatures are possible. The skin effect tracing
system requires a single conductor in a metal tube specifically
to create heat in the tube, although not s t r i c t l y by induction.
This is permissible because the temperature of the system is
427-12(g)-(New)(HOD 1978 NEC): Reject
CMP 10
SUBMITTER: Manufacturing Chemists Association
Ph-OI~O-S~CT. 54
Where a pipeline or vessel wall is used as the heating
element, the pipeline or vessel shall conform to the following:
(1) thermally insulated for safety of personnel; (2)
electrically insulated from supporting structures; (3) protected
from physical contact by suitable guards or by location; (4)
visibly marked as being electrically energized; (5)
voltage-to-ground of the pipeline or vessel shall be below 50
volts AC; (6) circuit-grounded or system- grounded in accordance
with Section 250-5(a).
SUBSTANTIATION: There is no need to recognize installation of
equipment used in industry but not previously covered in the
NEC. This type of heating has been practiced successfully by
industry for many years. The combination of all types of
pipeline and vessel heating into a single article is highly
desirable.
PANEL RECOMMENDATION: Reject.
PANEL COt~MENT: See Panel action on Proposal No. ~47.
VOTE ON PANELRECO~IENDATION: Unanimously Affirmative.
COMMENTON VOTE:
ERICKSON: I feel the Panel Comment should be changed to "CMP
agrees with intent of proposal." See action on Proposal No. 47.
427-23(a): Accept
CMP 10
SUBMITTER: Warren H. Cook, IEEE
~L:
55 Delete: "and shall be supplied by the heating
manufacturer. ~
SUBSTANTIATION: The National Electrical Code should address
i t s e l f to safety and not source of supply.
PANEL RECOMMENDATION: Accept.
I PANEL COMMENT: See Proposal No. 47.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Eichhorn.
J EXPLANATIONOF VOTE:
EICHHORN: SectTon 427-23(a). As in Proposal 45, the concern
is about general approval for field connection of power supply
leads to the electric heating elements.
I t is suggested that existing Section 427-23(a) to be used for
Section 427-14(e) with this added.Exception: "Fieldconnection of power supply nonheating leads
(cold leads) to the electric heating elements shall be permitted
where the means of connection is identified as suitable for this
purpose."
Section 247-20(b). The words "attachn~nt plug of" were
omitted between "factory installed" and "cord-and plug-connected
equipment."
427-23(b), Exception-(New): Reject
CMP 10
SUBMITTER: Warren H. Cook, IEEE
56 Add exception as follows:
Exception: Metal conduit or metallic tubing shall not be
required for cord connected equipment when adequately protected
by other means.
SUBSTANTIATION: The placement of heating wire directly on the
vessel to be heated requires a flexible, open connection between.
the heating wire and the raceway system. This flexible open
connection has been found to be satisfactorily and suitably made
by extending the cold leads in protected manner from the heated
component to a f i t t i n g of the raceway system. A suitable length
has been found to be 18 inches maximum.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 47.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
427-25: Accept
CMP 10
SUBMITTER: TSC-Approvedfor the Purpose
57 See the Technical Subcommittee "Recomendations"
under the definition of "Approved for the Purpose" in Article
100.
189
known, and is part of the design.
427-30. Self explanatory.
427-31. Skin effect tracing systems should be grounded at one
point, even though they are universally d i r e c t l y mounted on
grounded pipes or vessels. Even in the unlikely occurrence of
an ungrounded pipe and a broken ground wire, there w i l l be no
harmful closed circuits i f contacted by personnel or conducting
material.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal.
See
action on Proposal No. 47.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
190
Diagram 430-1: Reject
SUBMITTER: Warren Anderson, Mount Vernon, WA
l~TOl~O~rAt-~.'3
Revisediagram as follows:
REPORT OF CODE-MAKING PANEL NO. I I
e
Diagram 430-I: Accept
SUBMITTER: A. P. White, Attleboro, MA
~
l
Part
Part
Part
Part
Part
".
Requirements for over 600 volts
Protection of live parts all voltages
Grounding
Tables
ARTICLE 430 -- MOTORS, MOTORCIRCUITS, AND CONTROLLERS
CMP 11
~Motor
Feeder Overcurrent Protection TO READ:
Motor Feeder Short Ciruit and Ground Fault
Protection.
CHANGE: Motor Branch Circuit Overcurrent Protection
TO READ: Motor Branch,Circuit Short Circuit
and Ground Fault Protection.
CHANGE: Motor Running Overcurrent Protection TO READ:
Motor Overload Protection.
CHANGE: Inherent Protection TO READ: Thermal
Protection.
SUBSTANTIATION: Related editorial revisions for the following
Sections: Diagram 430-I; Part C Heading; Sections 430-32(a-1),
-32(d), -351b), -37, Table 430-37 Heading~ -38, -39, -40,
-42(a), -42(b), -42(c), -43, -52, -53(a-3), -53(c), - 5 3 ( c - I ) ,
-53(d), -55, -125(a), -152 Table Heading; Example No. 8; 440-21.
E d i t o r i a l revision of A r t i c l e s 430 and 440 of the 1975 NEC
were f o r c l a r i f i c a t i o n of the terms - overload, overcurrent, and
s h o r t - c i r c u i t and ground-fault p r o t e c t i v e device. Since not a l l
the changes required were made, t h i s series of related proposals
are submitted to complete the e d i t o r i a l changes and preserve the
intent f o r the terms "overload," "overcurrent," and
" s h o r t - c i r c u i t and ground-fault" devices.
This follows where the e d i t o r a l revisions in the 1975 NEC
confirmed that "overload ( f o r motors)" in A r t i c l e 430 means
current due to overload and f a i l u r e to s t a r t and excludes f a u l t
currents caused by short c i r c u i t and ground f a u l t .
The
e d i t o r i a l revisions in the 1975'NEC replaced references to
"motor running overloads" and"motor running overcurrent" with
the term, "motor overload," wherever i t was the intent that the
currents involved were due to both overload and f a i l u r e to s t a r t .
A d d i t i o n a l l y , the motor branch c i r c u i t p r o t e c t i v e device such
as in Part D was confirmed as intended f o r protection against
only s h o r t - c i r c u i t and ground-fault currents and excludes
overload currents.
In contrast, the term, "overeurrent,"
includes any current r e s u l t i n g from overload, short c i r c u i t and
ground-fault. The e d i t o r i a l revisions in the 1975 NEC intended
to use the term, " s h o r t - c i r c u i t and ground-fault p r o t e c t i v e
device" in place of the term, "overcurrent" wherever i t was the
i n t e n t that only f a u l t currents were involved due to short
circuit and ground.
. ,
PANEL RECOMMENDATION: Accept as Revised:
The same editorial changes required by this Proposal are also
required in additional sections of Articles 430 and 440 as
follows:
430-3. In paragraph 2 line i delete the words "running
overcurrent" and replace with the word "overload."
430-6 (a). In line 4 delete the words "overcurrent devices" and
replace with the words "short-circuit and ground-fault
protection."
In lines 6 and 7 delete the words "motor-running overcurrent"
and replace with the words "motor overload.~'
430-6 (b). In lines 4 and 5 delete the words "motor running
overcurrent" and replace with the words "motor overload."
430-6 (c). In lines 3 and 4 delete the words "overcurrent
devices" and replace with the words "short-circuit and
ground-fault protection."
430-7 (b). In line 6 delete the word "overcurrent" and
replace with the words "short-circuit and ground-fault."
430-7 (d). In lines 5 and 8 delete the we~d "overcurrent" and
replace with the words "short-circuit and ground-fault
protective."
430-8. In lines 4 and 6 delete the words "motor-running
overcurrent" and replace with the words "motor overload."
In line 7 delete the word "overcurrent" and replace with the
words "short-circuit and ground-fault."
430-54. In line 2 insert the words "short-circuit and
ground-fault" after the words "branch-circuit."
440-22 (b). In line 7 insert the words "short-circuit and
ground-fault" after the word "equipment."
Paragraph (b) (1) line 2 insert the words "branch-circuit
short-circuit and ground-fault" after the words "setting of the."
Paragraph (b) (2) line 2 insert the words "branch-circuit
short-circuit and ground-fault" after the words "setting of the."
Paragraph (b) (2) Exception No. I line 4 delete the word
" c i r c u i t " after the word "maximum" and replace with the words
"branch-circuit short-circuit and ground-fault."
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
CMP 11
A
J
K
L
M
Rl~tt,~ 014grm IS fo110ml:
SUPPLY
FE£~ OVIS~K:UR~
NOT~ ~.EO~
m~T
PART B:
$4¢. 430-24. 25,
ROTOR OI~.Olq~ECTINGM£ANS
PART H
M~TO~~
~ OriENT
~IIEC'TION
PART 0
MOTCRCCKT~LL£R & MOTOR
pAJITS G II F
RUI~4I~ OV£RCURRINT
~cTIo~
140TOR CI~UIT O~40L~TORS
MOI~}RI¢4ER~$TPROTIECTION ~
$ECOROARYCOXTRO~ER
PART C
PA~T It:
SIC. 430-Z2
PART A & C
PA~cr B:
S ~ . 430-Z3
PART B: S ~ . 430-23 & Art.. 470
SUBSTANTIATION: Diagram 430-1 would be easier to understand and
add c l a r i t y to the code i f i t were redrawn so that the sequence
of devices more closely follows the actual alignment of devices
that are found in the f i e l d .
PANEL RECOMMENDATION: Reject.
PANEL CO~4ENT: Supporting comment is not persuasive as to
necessity. No additional clarification would be achieved by
this Proposal.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
430-2: Accept
CMP 11
SUBMITTER: Edwin H. Luoma, Reliance Electric Co.
IsITOIRTS'A~-T.'4
In the second sentence of the f i r s t paragraph add
"overload" after the word "additional."
SUBSTANTIATION: The second sentence is not complete in meaning
wltnout tne word "overload" as shown in the revised sentence
above. We feel the intent of the code would also be satisfied
with the addition of the word "overload."
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
430-2: Reject
CMP 11
SUBMITTER: Idaho Chapter IAEI
I~RI33R}~FAL-T." 5
In Section 430-2 delete the second sentence and
move ~ t
sentence to Section 430-52.
SUBSTANTIATION: (See proposal for new Exception No. 2 for
Section 430-52.)
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The revised wording adequately reflects Panel's
intent. See Proposal No. 4.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
430-4: Reject
CMP 11
SUBMITTER: Robert G. MacManus, Pawtucket, RI
~
6
Delete the figure "50" and replace with "25."
~B-STAI~TIATION: The NEC has for many years allowed one piece of
equipment to be "in sight from" another piece of equipment i f i t
is visible and not more than 50 feet distant. However, the rule
does not take ihto consideration the fact that temporary or
permanent equipment or material could later block the view and
cutting the distance in half would make for much safer
conditions. I t will be noted that Section,430-102 no longer
allows the discennecting means to be locked in the open position.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting con~nent does not Justify the
proposed change.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
Diagram 430-I: Accept
CMP 11
SUBMITTER: TSC-Nominal Voltage
~ITOIR~S-AL-T.'2
In the second line add "nominal" after "600"
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
191
430-5: Accept
~
CMP 11
SUBMITTER: Larry T. Smith and LaVerne E. Stetson, Lincoln, NB
I~TOPO-SA
' -L-~: 7
Changeto include Article675. Electrically
~ r
controlled irrigation machines.
SUBSTANTIATION: The readers attention should be directed to the
provisions of Article 675. Many installers, for example, are
not aware of the equivalent current ratings given in Section
675-22.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
430-7(a)(14)-(New): Reject
CMP 11
SUBMITTER: Kenneth L. Paape, Allen-Bradley Co.
I~ITOIR)~-~.
• 8
Add new (14) as follows:
~Overload
relay class, where the motor is not marked
"Thermally Protected" or "Impedance Protected." (See Section
430-41).
SUBSTANTIATION: A system of class designations, Class 10, 20 or
30, exists for overload relays. .(See paragraphs 23.2 and 36.15
of UL508). The numerals in these class designations (e.g., 10,
20 or 30) indicate the maximum time in seconds required for the
overload relay to t r i p at a current which is equal to 600% of
the current element rating. Since an overload relay must
ultimately t r i p at 100% of its current element rating and within
8 minutes at 200% of its current element rating, a time-current
characteristic can be drawn for each overload relay class. With
this information the motor manufacturer is the most qualified to
select the overload relay class which best matches the motor
insulation system and heating characteristics under
acceleration, overload, or locked rotor conditions.
Neither
installers nor inspectors have easy access to the technical
details required to select an overload relay of the proper class.
A more detailed explanation of the overload relay class
designation system is included with a companion proposal for a
new Section 430-41 to require that overload relays be marked
with their class designation. The time-current curves of 3
overload relay classes and table of expected motor insulation
l i f e at different temperatures prepared for the Section 430-41
proposal are attached.
All overload relay current elements are selected on the basis
of their current rating (ultimate t~ip current) regardless of
overload relay class, yet overload relays with high class
designations require more time to t r i p at 600% of their rating.
Relays which take longer to t r i p at 600% of their rating provide
more time for the motor and its load to accelerate to f u l l
speed. Section 430-34 requires that the overload relay have
sufficient time delay to permit the motor to start and
accelerate its load. Only the motor manufacturer knows the
maximum load (in terms of inertia and acceleration time) that
the motor can bring up to speed without overheating. The
overload relay class that best conforms to the motor capability
ought to be shown on the motor nameplate.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel believes that extending the
requirements as indicated by this Proposal is not necessary as
the Code now permits this marking.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Lopez."
COMMENTON VOTE:
SCHRAM: See explanation of negative vote on Proposal No. 9.
We believe the marked overload relay class should be the maximum
class, in accordance with Proposal No. g.
EXPLANATION OF VOTE:
LOPEZ: I disagree with the Panel's Recon~nendation since I
believe this proposal will improve the motor overload
protection. The marking of overload relay class on the motor
nameplate will help the users with the selection of the proper
overload relay t o u t i l i z e .
430-7(a)(14)-(New):
Reject
.
SUBMITTER: Marvin T. Stevens, Greendale, WI
CMP 11
~TOFOTATT."9
Maximum overload relay class, where the motor is not
marked "Thermally Protected" or "Impedance Protected."
(FPN) See Sections 430-34 and 430-40.
SUBSTANTIATION: This proposal is one of a package of three and
should be considered with proposals relating to overload relay
class designations submitted for Sections 430-34 and 430-40.
At the time a motor manufacturer designs a motor he takes Into
consideration the maximum inertia load that the motor should be
capable of accelerating.
The motor manufacturer also knows the
maximum allowable locked motor time which his motor can endure
without undue deterioration of the insulation.
Both the motor acceleration time and the maximum allowable
locked rotor time for the motor can be related to the
time-current characteristics of overload relays and the overload
relay class requirements of ANSI C33.76-1976. Nationally
recognized testing laboratories verify time-current
characteristics in accordance with ANSI C33.76-1976 before
awarding listing to a line of overload relays. Since the system
of class designation exists and is based on fundamental data
best interpreted by the motor manufacturer, i t would seem
prudent to require the maximum overload class to be marked on
motor nameplates where the motor does not include thermal or
impedance protection. I t is quite possible today to have an
overload relay selected properlywith regard to motor f u l l load
current and yet have motor burnout because the wrong class of
overload relay was used. Unless the motor is marked with its
maximum overload relay class, there is no way for an electrician
or inspector to know i f the overload relay is the proper class
for the motor.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT:. The Panel believes that extending the
requlrements as indicated by this Proposal is not necessary as
the Code now permits this marking.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Schram.
EXPLANATION OF VOTE:
SCHRAM: The matching of the locked rotor characteristics of
motors and overload relay protective devices is an important
part of motor protection that is not now covered in the NEC.
The marking of the maximum overload relay class on the motor
would aid in providing proper levels of protection.
430-7(d): Reject
CMP 11
SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration
T
430-7(d): Reject
CMP 11
SUBMITTER: Alton R. Thompson, Durham, NC
11 Add a sentence before the last sentence of the
T l - ~ r a g r a p h as follows:
In no case shall the marked maximum rating'of the circuit
overcurrent device be less than the marked minimum supply
c i r c u i t conductor ampacity.
SUBSTANTIATION: The actual marked values may be greater than
the calculated minimum, and/or may be less than the calculated
maximum. Under the present rules, the marked maximum rating of
the overcurrent device (fuse or circuit breaker) could be less
than the marked minimum supply circuit conductor ampacity,
especially since the marked maximum fuse or circuit breaker
rating is normally reduced from the calculated maximum to a
standard rating as given in Section 240-6. The possibility of
this occurrence is greatest when a substantial part of the
combination load is electric resistance space heating. There
are products on the market with this cross-over of marked
limits. Although Section 430-53(c)(4) permits the rating of the
fuse or circuit breaker to be increased to the next standard
rating higher than the conductor ampaclty (by reference to
Section 240-3 Exception No. 1), the marked maximum rating of the
fuse or circuit breaker cannot be exceeded per Section 430-54.
The change Is to remove unintended permission for a crossover of
the minimum and maximum marked values.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel comment on Proposal No. 10.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Schram.
EXPLANATION OF VOTE:
SCHRAM: See Con1~ent in Proposal No. 10.
192.
,/
~
PROPOSAL: 10 Add a sentence before the last sentence of the
~ragraph
as follows:
In no case shall the marked maximum rating of the circuit
overcurrent device be less than the marked minimum supply
circuit conductor ampacity.
SUBSTANTIATION: The actual marked values may be greater than
the calculated minimum, and/or may be less than the calculated
maximum. Under the present rules, the marked maximum rating of
the overcurrent device (fuse or circuit breaker) could be less
than the marked minimum supply circuit conductor ampacity,
.especially since the marked maximum fuse or circuit breaker
rating is normally _reduced from the calculated maximum to a
standard rating as given in Section 240-6. The possibility of
this occurrence is greater when a substantial part of the
combination load is electric resistance space heating. There
are products on the market with this cross-over of marked
limits. Although Section 430-53(c)(4) permits the rating of the
fuse or circuit breaker to be increased to the next standard
rating higher than the conductor ampacity (by reference to
Section 240-3 Exception No. 1), the marked maximum rating of the
fuse or circuit breaker cannot be exceeded per Section 430-54.
The change is to remove unintended permission for a crossover of
the minimum and maximum marked values.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VO~E ON PANEL RECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Schram.
EXPLANATION OF VOTE:
SCHRAM: Whlle we agree a design consideration is involved, i t
is the design of the marking. We do not believe the Code should
permit a marking which in conflict with'the intent, as stated in
the proposal.
SUBSTANTIATION:
The conductor termination means furnished
with motor controllers are evaluated as part of the controller
in order to obtain listing by a nationally recognized testing
laboratory. Most installing electricians are not aware that
changing the termination of a controller n u l l i f i e s this l i s t i n g .
Field experience has shown that the screw ttlpe lugs furnished
with listed motor controllers are occasionally replaced with
crimp type lugs at the time the controllers are installed even
though the,replacement lugs may not include an anti-rotation
feature which the original termination had. When the individual
making the installation uses a listed lug as a replacement with
no concern for its length, he can create a situation where the
wiring space is not adequate and the conductors are subject to
damage as they are forced between the end of the lug and the
wall of the enclosure.
In addition, inadequate wiring space may lead to improper
orientation of the new lugs with a resulting loss of electrical
clearance. Since nationally recognized testing laboratories
l i s t lugs with no constraint on their length, and only a small
percentage of all motor controllers manufactured are used with
lugs other than those furnished, there is no practical way for a
controller manufacturer to anticipate the wiring space that may
be required under changed lug conditions. The individual
choosing to change the conductor termination should be made
responsible for proper lug selection.
Proposed Table 430-10 is based on the table recommended by
Underwriters Laboratories as a result of a fact=finding
investigation sqggested by CMP 11 regarding adequat~ wiring
space In enclosures for motor controllers.
PANEL RECOMMENDATION: Reject.
PANbL COMMENT: Accepted Proposal No. 15.
VOTE ON PANELRECOMMENDATION:' Unanimously Affirmative.
430-10 and Table 430-10-(New): Reject
CMP 11
SUBMITTER: K. L. Paape, Allen-Bradley Co.
!~TOIRT~:/~-~.. 12 Revise 430-10 by adding a new paragraph
a-'fq!-~'6-'t'ITe fine print note as follows:
Where the conductor termination means (lugs) supplied by the
manufacturer of a listed motor controller are replaced by other
conductor termination means, conductors shall not be deflected
at a terminal unless bending space In accordance wlth Table
430-10 is provided. And add a new table as follows:
Table 430-10. Minim~ Wlre Bending Space at
Terminals in Inches
AWG or
Circular-Mil
Wires per Terminal
Size of Wire
1
2
3
4
5
14
12-6
4-3
2
1
0-00
000-0000
250-MCM
300-350 MCM
400-500MCM
600-700 MCM
750-900 MCM
1000-1250 MOM
1500-2000 MCM
Not Specified
1 1/2
2
2 1/2
3
3 1/2 5
4
6
4 1/2 6
. 5
8
6
8
8
8
i0
12
10
12
7
8
8
10
10
12
14
....
....
10 -12 ._
12 14
14
16
16
18
Bending space at terminals shall be measured in a s t r a i g h t
l i n e from the end of the lug or wire connector (in the d i r e c t i o n
that the wlre leaves the terminal) to the wall or b a r r i e r .
SUBSTANTIATION: The conductor termination means furnished with
motor c o n t r o l l e r s are evaluated as part of the c o n t r o l l e r in
order to obtain l i s t i n g by a n a t i o n a l l y recognized testing
laboratory. Most i n s t a l l i n g e l e c t r i c i a n s are not aware that
changing the termination of a c o n t r o l l e r n u l l i f i e s this l i s t i n g .
F i e l d experience has shown that the screw type lugs furnished
w l t h l i s t e d motor c o n t r o l l e r s are occasionally replaced with
crimp type lugs at the time the c o n t r o l l e r s are i n s t a l l e d even
though the replacement lugs may not include an a n t i - r o t a t i o n
feature which the or.igianal termination had. When the
individual making the i n s t a l l a t i o n uses a l i s t e d lug as a
replacement with no concern f o r i t s length, he can create a
s i t u a t i o n where the wiring space !s not adequate and the
conductors are subject to damage as they are forced between the
end of the lug and the wall of the enclosure.
In addition, inadequate wiring space may lead to improper
orientation of the new lugs with a resulting loss of electrical
clearance. Since nationally recognized testing laboratories
l i s t lugs wlth constraint of their length, and only a small
percentage of all motor controllers manufactured are used with
other than the lugs furnished there is no practical way for a
controller manufacturer to anticipate the wiring space that may
be required under changed lug conditions. The individual
choosing to change the conductor termination should be made
responsible for proper lug selection.
Proposed Table 430-10 is based on present Table 373-6(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Accepted Proposal No. 15.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
430-10: Reject
CMP 11
SUBMITTER: R. E. Smith, Cutler-Hammer Inc.
14 Revise as follows:
~ .
Wiring Space in Enclosures.
(a) General. Enclosures for motor controllers and
disconnecting means shall not be used as junction boxes,
auxiliary gutters, or raceways for conductors feeding through or
tapping off to the other apparatus unless designs are employed
which provide adequate space for this purpose.
(b) Wire Bending Space. Minimum wire bending space shall be
in accordance with Table 430-10(b) and measured in a straight
line from the end of the terminal connector, supplied with the
controller (In the direction the wire leaves the terminal) to
the enclosure wall or barrier. Alternate terminals shall be of
a type identified for use with the controller and shall not
reduce the minimum wire bending space.
TABLE 430-I0(B). MINIMUMWIRE BENDING SPACEAT
TERMINALS OF ENCLOSEDMOTORCONTROLLERS IN INCHES
AWG or
Circular-Mil.
Size of Wire
not specified
....
14-I0
8-6
1 I/2
....
4-3
2
....
2
2 1/2
....
1
3
....
0-00
3 I/2
....
000-0000
7
7 ' 12
250MCM
8 1/2
8 1/2 12
300-350MCM
I0
I0
15
400-500MCM
12
15
t 12
600-700MCM
15
15
18
750-900MCM
18
18
21
SUBSTANTIATION: An Underwriters Laboratories fact-finding
investigation has shown the need for a wire-bending space table
for motor controllers. The above proposed table was developed,
taking into consideration the following diversity factors. The
UL investigation has confirmed that these factors have an
influence on the amount of wlre-bending space required. Several
of these factors are present in any given motor controller
installation.
I . The depth of motor controller enclosures provides added
volume which, allows the forming of wires, sizes AWG 2/0 and
smaller, to f a c i l i t a t e their connection to the controller
connectors.
2 . Wire ampacity selection is based on motor horsepower and
voltage rating. The value of motor current is always less than
the current rating of the standard motor controller which would
be used.
Example: A motor rated 50HP at 460 volts (65FLA) requires
wire rated at 82 amperes (1.25x65) which f a l l s within the
ampacity rating of #2AWG copper wire (95A) or #1AWG aluminum
wlre (85A).
The standard motor controller with a max. rating of 50HP, 460
volts has a current rating of 90A and is provided with wire
connectors capable of accepting #1AWG copper wire. When
designed for use with aluminum wire, the wire connector is
capable of accepting #2/OAWG aluminum wire. The net result is
that the connector wire range of the motor controller usually
exceeds the size of the wire required for the installation. The
430-10: Reject
CMP 11
SUBMITTER: Kenneth L. Paape, Alle~-Bradley Co.
PITOPO-~7~-T. 13
ExpandSection 430-10 by adding a paragraph and
follows:
430-10 Wiring Space in Enclosures. Enclosures for motor
controllers and disconnecting means shall not be used as
Junction boxes, auxiliary gutters; or raceways for conductors
feeding through or tapping off to the other apparatus unless
designs are employed which provide adequate space fop this
purpose.
See Section 373-8 for switch and overcurrent-device enclosures.
Where the conductor termination means (lugs) supplied by the
manufacturer of a listed motor controller are replaced by other
'lugs, these lugs shall be sized so that wire bending space in
accordance with Table 430-10 is available.
Table 430-10 - Minimum Wire Bending Space
at Terminals in Inches
Max. Conductor
Conductorsper
Size
AWG or MCM
1
IO •
Not Speclfled
6
1 1/2
3
2
2
2 i/2
1
3
2/0
3 1/2
4/0
7
250 MCM
8 I/2
350 MCM
'
10
500 MCM
12
700 MCM
15
go0 MCM '
18
Terminal
2
3
7
8 1/2
10
12
15
18
12
12
15
15
18
21
Wires Per Terminal
1
2
193
shall have minimum dimenslons and usable volumes in accordance
with the following:
(1) For motors rated one horsepower and smaller, having not
over four leads and having terminal housing p a r t i a l l y or wholly
integral with the frame or end shield. The volume of the
terminal housing shall be not less than 2 'cubic inches per
wire-to-wire connection. The minimum cover opening shall be no
less than 1.5 inches.
(2) For alternating current motors, having a maximum of 12
leads entering the terminal box shall incorporate terminal boxes
no smaller than as shown in Table 430-12(b)(1).
(3) For direct current motors having a maximum of 6 leads
entering the terminal box shall have dimensions and usable
volumes not less than shown in Table 430-12(b)(2).
UL fact-finding investigation indicates that this is an
important factor which facilitates wire installation.
3. In the wire range of 2/OAWG and smaller, most motor control
installations use copper wire. The UL fact-finding
investigation indicates that copper wire is easier to
manipulate. Further, a smaller size copper wire is generally
used for the equivalent ~l~)acity rating of aluminum wire.
4. Motor controllers are designed to permit the additio~of
accessories such as control transformers, auxiliary contacts,
pushbuttons, selector switches, pilot lights, etc., which result
in oversize enclosures for many applications.
5. Since motor controllers are not permitted to be used as
junction boxes by the NEC, only one wire per terminal need be
considered for wire sizes 2/OAWG and smaller.
6. Motor controllers are generally easily removed from their
enclosures which can improve access to the wire connectors and
f a c i l i t a t e the connection of wires to the connectors.
7. Manymotor controllers are designed in a manner which al!ows
easy removal of the wire connectors from the coBtroller. The
connector can be fastened to the wire and reassembled to the
controller.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Accepted Proposal No. 15.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
ATTACHMENT A
Table 430-12(b)(1)
Alternating-Current Motors
Motors Over 11 Inches in Diameter
Max. Full-load
Current for Three
phase Motors with
Max.'of Twelve
Leads
430-10(b)-(New): Accept
CMP 11
SUBMITTER: Harold E. Whiting, St. Charles, IL
!~TOl~O'S'At-~". 15
Identify present paragraph as (a) General.
~ w
(b) and Table 430-I0(b) as follows:
(b) Wire Bending Space in Enclosures. Minimum wire bending
space within the enclosures of motor controllers shall be in
accordance with Table 430-I0(b) when measured in a straight line
from "the end of the lug or wire connector (in the direction the
wire leaves the terminal) to the wall or barrier. Where
alternate wire termination means is substituted for that
supplied by the manufacturer of the controller they shall be of
a type identified by the manufacturer for use with the
controller and shall not reduce the minimum wire bending space.
Table 430-10(b). Minimum Wire Bending Space at the Terminals
of Enclosed Motor Controllers (In Inches)
AWG or
Circular-Mil
Size of Wire
14 - 10
8 - 6
4 - 3
2
1
-
i/0
2/0
3/0-- 4/0
250
300
350 - 500
600 - 700
750 - 900
5
6
5
6
7
8
10
12
14
18
7
8
10
12
16
19
Usable
Volumn
Minimum
~ubic
Inches
Typical
Maximum
Horsepower
Three Phase
230 volt
460 volt
Amperes
45
70
110
160
250
400
600
*Wires Per Terminal
1
2
Not specified
1 1/2
2
2 I/2
. 3
~
Terminal
Box
Minimum
Dimension
Inches
w
2.5
3.3
4.2
5.4
7.0
9.3
10.7
26
55
100
190
330
600
1100
15
25
40
60
100
150
250
30
50
75
125
200
300
500
Table 430-12(b)(2)
Direct-Current Motors
Motors Over 11 Inches in Diameter
Maximum Full-load
Current for
Motors with
Maximum of Six Leads
Terminal Box
Minimum
Dimensions
Inches
Usable
Volume
Minimum
Cubic Inches
3.3
4.2
5.4
7.0
g.3
10.7
15.0
5b
100
190
330
600
1100
2000
Amperes
68
105
165
240
375
600
900
*Where provision for 3 or more wires per terminal exists the
minimum wire bending space shall be in accordance with
requirements of Article 373.
SUBSTANTIATION: A fact finding investigation by a nationally
recognized testing laboratory has indicated a need to specify
the wire bending space necessary within enclosed motor
controllers. Evidence also indicates this space should be
different for I and 2 wires per terminal from that required for
cabinets and cut out boxes as listed In Table 373-6(a) and
therefore a separate table in 430-10 is required.
The table presented in this proposal provides adequate space
for wiring by experienced installers using approved wiring
techniques without increasing the unsupported lengths of wire to
dimensions which might permithazardous deflection during high
current fault conditions.
Control of the type of alternate wire termination means must
be l e f t with the manufacturer of the controller to assure
l i s t i n g requirements and wire bending space requirements of the
controller are not v i o l a t e d .
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOI~ENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
SCHRAM: An affirmative vote is cast to support the addition
of bending space requirements in Article 430. However, i t
should be noted that the proposal differs in several respects
fro~ the proposals being considered for Article 373. We believe
the requirements in Article 430 would need to treat motor
control centers, which have some design elements similar to
switchboards and others similar to motor controllers, in a
manner consistent with the treatment proposed for Article 373.
SUBSTANTIATION:' Most users of motors find the terminal box
sizes Ilsted in present Sec, 430-12(b) to be entirely
inadequate. This inadequacy stems both from insufficient space
for all the wires and splices and from the necessity for
oversharp bending of the wires. Both of these contribute to
physidal overstressing of the insulation which results in
inordinate failure rates of conductors in the termlnal boxes.
In seme studies i t has been found that one-quarter of all
"motor" failures occurred in the terminal boxes. While failure
rate is not a basic criterion of the Code, there is ample
evidence in other articles to prove that adequate wiring space
is prescribed for freedom from failures, a major cause of fires;
Articles 370, 373 and others require more satisfactory space for
making bends and connections.
Knowledgeable users have simply been specifying larger
terminal boxes on factory orders to obtain serviceable
equipment. Others, and those purchasing motors from stock,
discard the original boxes and fabricate more adequate ones for
the installation. The manufacturers hold that Original
Equipment Manufacturers buy the major proportion of motors, and
require the very minimum sizes of terminal boxes. I t must be
remembered that few OEM's actually use these items and many do
not even wire up the motors. In any event, OEM's do not
ordinarily become involved with maintaining the motors,
replacing bearings, etc. which require disconnection and
reconnection of the motor, involving disassembly and reasse~foly
of the wiring In the terminal boxes. For this very important
reason, i t is suggested that the OEI~viewpoint is unsound, and
i f Sec. 430-12(b)is based on this, the section would be better
deletes from the Code.
430-12(b): Accept
CMP 11
SUBMITTER: A. C. Clark, Manufacturing Chemists Assn.
!~R-OIs~L-~." 16 Revise as follows:
---Tb-)--l~imensions and Space--Wire-To-Wire Connections. When
these terminal housings enclose wire-to-wire connectlons, they
194
I t Is well known that the bending of stranded wires more
sharply than as outlined i 9 Sec. 373-6 for a single 90° bend, or
double these dimensions for a 180° bend will result in
inserviceable operation, through stretching of the outer strands
and inordinate pressure on the insulation. Space and size of
motor terminal boxes requires that the splices be made up
outside the boxes, then formed into the boxes, usually incurring
a U-bend. The proposed sizes of the terminal boxes in Sec.
430-12(b) provide space for making these bends and splices
without exceeding the bending sharpness specified in Sec. 373-6.
PANEL RECOMMENDATION: Accept as Revised:
First two Tables on page 292 in the 1978 NEC to be shown as in
Attachment A. Also in Attachment A, Table 430-12(b)(1), column
3 entitled "Usable Volume Minimum Cubic Inches," change fourth
figure down from "190" to "180." In same Table, column 2
entitled"Terminal Box Minimum Dimension Inches" change the
following: from "4.2" to "4.0," "5.4" to "5.0," "7.0" to "6.0,"
"9.3 to "7.2" and "10.7" to "8.8."
In Table 430-12(b)(2), column 2 entitled "Terminal Box Minimum
Dimensions Inches" change the following: from "4.2" to "4.0,"
"5.4" to "5.0," "7.0" to "6.0," "9.3" to "7.2," "10.7" to "8.8"
and "15" to "10.7." In same Table, column 4 entitled "Usable
Volume Minimum Cubic Inches," change third figure down from
"190" to "180."
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Wood.
EXPLANATION OF VOTE:
WOOD: The revision made by CMP 11 does not help to a l l e v i a t e
the space problem in smaller sized motors as o r i g i n a l l y
proposed. The Panel's revisions r e s u l t in V i r t u a l l y no change
from present values.
430-16: Reject
CMP 11
SUBMITTER: O. E. Dillon, Border County Div. IAEI
PITOIRT~_-~.'20 Revise as follows:
Exposure to Dust Accumulation. In locations where dust
or flying material collects on or in motors in such quantities
as to cause the motor temperature to rise beyond its rating, a
motor that will not overheat under the prevailing conditions
shall be used. Conditions may require the use of enclosed
pipe-ventilated motors, or enclosure in separate dust-tight
rooms, ventilated from a source, of clean air.
SUBSTANTIATION: The use of the words "seriously interfere" and
"dangerous temperatures" renders this section legally
unenforecable. See the attached opinion* of the San Diego City
Attorney.
*See Border County Div. IAEI substantiation for CMP 1 Proposal
No. for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: No significant contribution to safety would
result.
VOTE ON PANELRECO~bMENDATION: Unanimously Affirmative.
430-22(a): .Accept
CMP 11
SUBMITTER: J. J. Kark, National Electrical Manufacturers
~ o n
PROPOSAL: 21 Revise the f i r s t paragraph to read as follows:
Branch-circuit conductors supplying a single "AC" motor, "or a
DC motor operating from a source other than a rectified
single-phase AC supply," shall have an ampacity not less than
125 percent of the motor full-load current rating.
Add the following new paragraph between the existing second
and third paragraph (retain the existing paragraph entitled
"Exception" as the fourth paragraph):
In case of direct-current motors operating from a single-phase
power supply, the conductors between the controller and the
motor shall have an ampacity of not less than the following
percent of the motor full-load current ratinggiven in Table
430-147:
(1) Where a r e c t i f i e r bridge of the single-phase half-wave
type is used, 190 percent•
(2) Where a r e c t i f i e r bridge of the single-phase full-wave
type is used, 150 percent.
SUBSTANTIATION: This proposal recognizes the existence of
significant form factors for integral-horsepower motors
operating from single-phase power supplies and the need t o
select conductors on the basis of rms current rather than on the
basis of average current. CMP-11may wish to e d i t o r i a l l y
restructure this section for any c l a r i t y believed necessary to
incorporate the intent of the proposal.
PANEL RECOMMENDATION: Accept as Revised:
Change existing Exception to Exception No. 1 and add the
following as Exception No. 2:
Exception No. 2: For direct current motors operating from a
rectified single-phase power supply, the conductors between the
controller and the motor shall have an ampacity of not less than
the following percent of the motor full-load current rating:
a. Where a r e c t i f i e r bridge of the single-phase half-wave
type is used, 190 percent.
b. Where a r e c t i f i e r bridge of the single-phase full-wave
type is used, 150 percent.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
Table 430-12(c)(1):
Accept
CMP 11
SUBMITTER: TSC-Nomina] Voltage
~
17 Change"volts" in the l e f t column heading to read
Volts"
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept as Revised:
I
In addition, f i r s t l i n e of f i r s t column should read "240 or
less" and second line of the f i r s t column "over 240 through 600."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
I
430-12(e)-(New): Accept
CMP 11
SUBMITTER:, Idaho Chapter IAEI
I~TOIsl~S'AT~.
• 18 Add a section (e) to Section 430-12.
~quipment
Grounding Connections. Equipment grounding
connection devices or f i t t i n g s as required by Section 250-113
shall be provided at motor terminal housings. Such devices or
f l t t i n g s shall be located so that the equipment grounding
conductor may be terminated either inside or outside the motor
terminal housing.
SUBSTANTIATION: Termination f i t t i n g s for grounding conductors
are not provided in motor terminal housings. Use of the cap
screws that fasten the motor terminal housing to the motor is a
violation of Section 250-i14(a). Th~ connection device or
f i t t i n g should be installable for use inside or outside the
motor terminal housing. This would then be compatible with the
permissive methods of Section 250-79(e) Installation-Equipment
Bonding Jumper.
PANEL RECOMMENDATION: Accept as Revised:
(e) Equipment Grounding Connections. A means for connection
of an equipment grounding conductor in accordance with Section
250-113 shall be provided at motor terminal housings for
wire-to-wire connections or fixed terminal connections. The
means for such connections shall be permitted to be located
either inside or outside the motor terminal housing.
Exception: Where a motor is installed as a part of
factory-wired equipment, which is required to be grounded and
without additional connection being required at the motor
terminal housing during equipment installation, a separate means
for motor grounding at the motor terminal housing shall not be
required.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
430-Part C: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
PROPOSAL: 22 Revise Part C Title as follows:
~ t o r
and Branch Ciruit Overload Protection.
SUBSTANTIATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
436-32 (a)(1): Accept
CMP 11
SUBMITTER: A. P. White, A t t l e b o r o , NSA
I~-R-O-FD-S-A-[-[.
" 23
In the last paragraph, delete the words
"motor-running" and replace with the word "motor."
SUBSTANTIATION: See A. P. White substantiation f o r proposal f o r
U1agram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
430-14(a): Reject
CMP 11
SUBMITTER: O. E. Dillon Border County Div. IAEI
19 Revise as follows:
~entilation
and Maintenance. Motors shall be accessible
to f a c i l i t a t e maintenance, such as lubrication of bearing and
replacing of brushes can be readily accomplished. Ventilation
will be sufficient to prevent the temperature rise of the motor
from exceeding that temperature for which the motor is rated.
SUBSTANTIATION: The use of the words "adequate" and "readily"
render thls section legally unenforceable. See the attached
opinion of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for CMP 1 Proposal
No. go for 110-16(a).
• PANELRECOMMENDATION: Reject.
PANEL COMMENT: No significant contribution to safety would
result.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
430-32(b): Accept
CMP 11
SUBMITTER: Roger C. Troupe, Fremont, NB
~ 2 4
Amendsection t i t l e to read: One Horsepower or
~nautomatically
Started.
SUBSTANTIATION: Section (b) is designed to be more lenient in
respect to the overload protection of motors, one horsepower or
less, not permanently installed, and within sight from the
location of the person starting them. Emendation of the wording
in the manner shown will make i t specifically understood that
paragraph (b) concerns motors started by personal intervention,
not just those started by a manual-type controller. (Note:
195
NONAUTOMATIC, as defined in Article 100.) Additionally, i t will
make clear that Sections (b) and (c) outline the required
overload protection on all continuous-duty motors rated one
horsepower or less.
PANEL RECO~IENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Motors with marked service factor
not less than 1.15 . . . . . . . . . . .
140 percent
Motors with a marked temperature rise
not over 40°C. . . . . . . . . . . . . . 140 percent
All other motors . . . . . . . . . . . . 130 percent
SUBSTANTIATION: See related proposals for Section 430-7(a),
motor namepTate marking, and for Sect!on 430-40, overload relay
marking.
Section 430-34 as presently written states that "the overload
device shall have sufficient time delay to permit the motor to
start and accelerate its load" without providing any means for a
user to select an overload relay to meet this requirement. The
control industry in NEMAStandard Part ICS 2-222 and a
nationally recognized testing laboratory in ANSI C33.76-1976
provide class designations as a way of indicating the time
available for the motor to accelerate its load to rated speed.
When a user selects the next higher size overload relay of a
lower class designation rather than one with a lower ratio of
t r i p ~current to motor full-load current, he sacrifices
protection unnecessarily. By taking f u l l advantage of an
existing class designation system, the user can provide
sufficient time for this motor and load to accelerate and s t i l l
retain the best running overcurrent protection.
For example, i f a Class 10 overload relay selected in
accordance with Section 430-32 does not provide sufficient time
for a service factor 1.0 motor to accelerate, present Section
430-34 raises the maximumpermissible overload relay trip
current from 115 percent to 130 percent of motor full-load
current. I f the load inertia is within that specified for the
motor (as i t should be) then the fault lies with the overload
relay and i t must be changed. Howeverby changing to a higher
class designation rather than a higher trlp current, the user
can bring his motor up to speed and s t i l l retain 115 percent
protection. Typical insulation l i f e for a Class B insulated
service factor 1.0 motor when operated at 115 percent of motor
full-load current is 5,000 hours compared to go0 hours when
operated at 130 percent of motor full-load current.
The ~lass designation system for overload relays provides for
motor acceleration without sacrificing running overcurrent
protection and should be used to reduce motor burnout, a
significant cause of electrical fires.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
~RECOMMENDATION:
UnanimouslyAffirmative.
430-32(b)(1), Exception: Accept
CMP 11
SUBMITTER: TSC-Nominal Voltage
25 Change"125 volts" to "127 volts"
~UU$1ANIIATION: To conform to the guidelines established by the
TSC on Nomlnal Voltages.
PANEL RECOMMENDATION: Accept as Revised:
I "Any such motor shall be permitted on a nominal 120 volt
branch circuit protected at not over 20 amperes."
VOTE ON PANELRECO!~ENDATION: UnanimouslyAffirmative.
430-32(d): Accept
CMP 11
SUBMITTER: A. P. White Attleboro, MA
, ~
26 Delete the word "running."
~!~'ARTIATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-34: Reject
CMP 11
SUBMITTER: Charles B. Kish, The Travelers Insurance CoL
l~TOI~S'AL-~.27" Delete the reference to "Section 430-32 (a)(1)."
~]I~:'~TI'IATION: While I agree that for motors of one horsepower
or less as referred to in Section 430-32 (c)(1) the higher
overload relay trip settings may be necessary due to heater
sizes available, and possibility of a serious accident is not
great; the use of oversize heaters on motors over one horsepower
referred to in section 430-32 (a)(1) is unwarranted and
dangerous. The ~ount of destructive power available in the
larger motors, is much greater. This danger is further
compounded i f used in a three phase circuit and single phasing
is caused by one line opening.
'PANEL RECOMMENDATION: Reject.
PANEL COMMENT: No evidence to support the suggested change.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 15.
NEGATIVE: Gubany, Kish.
EXPLANATION OF VOTE:
GUBANY: I am voting negative on Panel rejection as I agree
with the author's supporting comments. With the ever decreasing
size and thermal capacity of motors, i t is more important than
ever that.motors be protected at values closer to their name
plate ratings.
KISH: Based on my original substantiation remarks for this
proposal that I submitted -- "While I agree that for motors of
one horsepower or less as referred to in Section 430-32(c)(1)
t h e higher overload relay trip settings may be necessary due to
heater sizes available, and possibility Of a serious accident is
not great; the 'use of oversize heaters on motors over one
horsepower referred to in Section 430-32(a)(1) is unwarranted
and dangerous. The ~ount of destructive power available in the
larger motors is much greater. This danger is further
compounded i f used in a three phase circuit and single phasing
is caused by one line opening." In addition I feel that when
larger heaters have to use i t indicates a misapplication of the
motor and we should not exceed the normal ,heater s~ze in order
to compensate for thls error.
430!35{a): Accept
CMP 11
SUBMITTER: A. P. White, Attleboro,'MA
PROPOSAL: 29 Delete the word "running" in line 2.
~]B'~FA-N-I~IATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-35(a): Accept
CMP 11
SUBMITTER: Roger C. Troupe, Fremont, NE
PITO-I~]~-~.'30 Amendsection to read: Nonautomatically
For a nonautomatically started motor, the running
overload protection may be shunted or cut out of the circuit
during the starting period, cut out cannot be l e f t in the
starting position and i f fuses or inverse time circuit breakers
rated or set at not over 400 percent of the full-load current of
the motor are so located in the circuit as to be operative
during the starting period of the motor.
SUBSTANTIATION: Substitution of the word, nonautomatlcally, for
manually In both instances makes i t readily understood that
Sections (a) and (b) are integral.
I t also allows the elimination of the explanatory sentence in
parentheses which reads "including starting wlth a magnetic
starter having pushbutton control," as the word nonautomatic
already has that meaning by the definition given i t in Article
100.
PANEL RECOMMENDATION: Accept as Revised:
In third line remove "running" and replace "may" with "shall
be permitted to."
In the 4th line replace the commawith "of the motor i f the
device by which the overload protection is shunted or."
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-34: Reject
CMP 11
SUBMITTER: Marvin T. Stevens, Greendale, WI
~
l TO~
l O~FA1-~
•. 28
Selection of Overload R e l a y . .
(a) Class Designation. I f not shunted during the starting
period of the motor as provided in Section 430-35, the class
designation of the overload relay selected in accordance with
Sections 430-32(a)(1) and 430-32(c)(I) shall not exceed the
maximum overload relay class shown on the motor nameplate.
Fine print note. See Section 430-40 for definitions.
(b) MaximumProtection Rati'oL Where the overload relay
selected in accordance with Section 430-32(a)(1) and
430-32(c)(1) is not sufficient to start the motor and accelerate
the load, an overload relay with a higher class designation
shall be used, provided the conditions of Section 430-34(a) are
met. Where the overload relay of the highest permissible class
is not sufficient to start the motor or to carry the load, the
next higher size overload relay of the highest permissible class
as shown on the motor nameplate shall be permitted to be used,
provided the rating (trip current) of the overload relay does
not exceed the following percentage of motor fu11-1oad current
rating:
430-35(b): Accept
CMP 11
SUBMIT-rER: A. P. White, Attleboro, MA
!~TOIR~'A-L-~.31 Deletethe word "running" in line one.
~:[]I~'TA]TTIATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
196
430-37: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
.l~ArOPO-S'AL-~.32 Delete the word "running" In line 2.
~'T;~ITTIATION: See A. P. White substantiation for proposal for
Dlagram 430-I
PANEl. RECOMMENDATION: Accept.
VOTE ON PANELRECOI~ENDATION: UnanimouslyAffirmative.
Table 430-37: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MAI IJRUPUbAL: 33 Delete the word "running" in the t i t l e .
~'IIb-S"FAI~rIATION: See A. P. White substantiation for proposal for
Diagram 430-I.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOP~IENDATION: UnanimouslyAffirmative.
I
430-38: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
~
34 Delete the word "running" in line 2.
~Jl]~TTA]~I'IATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMI~ENDATION: UnanimouslyAffirmative.
430-39: Accept
CMP 11
SUBMITTER: A. P. White, Attlebo'ro, MA J
~
35 Delete the word "running" in line 2.
~S'~'A]~TIATION: See A. P. White substantiation for proposal
for Diagram 430-I.
PANEL RECO~HENDATION: Accept as Revised:
I Also delete "Running" in t i t l e .
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
I
I
430-40: Accept
CMP 11
SUI~HITT£R: A. P. White, Attleboro, MA
~
36 Delete the word "running" in line 2.
~'UI~'A]~IATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430~40: Accept
CMP 11
SUBMITTER: KennethL. Paape, Allen-Bradley Co.
!~TOPO'S'At-~. 37 Add a new paragraph as follows:
overload relays shall be marked with their
short-circuit, withstand rating. Where a current element
selection table is furnished with the overload relay, showing
the current element short-circuit withstand ratings (or a method
for determining them) on the table shall be permitted.
SUBSTANTIATION: Section 110r10 requires those components that
do not play an active role in clearing a short-circuit to have a
short-circuit withstand rating which must be considered in
selecting an overcurrent device. Manufacturers of thermal
overload relays can measure or calculate the amount of energy
that each current element can absorb without burnout under
short-circuit conditions in order to qualify for listing by a
nationally recognized testing laboratory ( i . e . , select the
proper fuse for short-circuit testing). This energy is equal to
the resistance of the thermal element multiplied by the I2t
let through by the fuse under short-circuit conditions. Hence
the short-circuit withstand rating of the current element can be
expressed in terms of 12t. Semeoverload relay current
elements designed foF low f u l l load motor currents (wire coil
type) can also be destroyed by the mechanical effect of high
fault currents, Ip. For such designs a maximum Ip withstand
rating would also have to be specified.
Users of motor control equipment have indicated to us that
short-circuit withstand ratings ought to be furnished with the
overload relay so that those who wish to protect current
elements from burnout under short-circuit conditions have the
information required to do so., They would install short circuit
protective devices that limit the 12t and Ip to not more than
the withstand ratings of the overload relays. L~sted short
circuit protective devices are available to provide this level
of protection.
Standards' presently used by nationally recognized testing
laboratories "permit listing of controllers with overload relays
that burn open and cause arcing under short-circuit conditions.
Merely complying with the Code or the information furnished with
the overload relay does not provide the user with sufficient
information to protect his current elements from burnout i f he
considers such protection essential. A standard method of
designating the short-circuit rating of thermal overload relays
is required so that manufacturers of short-circuit protective
devices can respond in like terms.
PANEL RECOMMENDATION: Accept.
V~TE ON PANEL RECOMMENDATION:
AFFIRMAIIVE: 13.
NEGATIVE: Cannady, Mierendorf, White, Wood.
EXPLANATION OF VOTE:
CANNADY: I wish to register my vote negative on Proposal No.
37 since this would require a marking that is presently
permitted. I t should not be required at this time since I t will
mislead those in the field and become a requirement for
inspection where I t is intended only to supply information.
MIERENDORF: Proposal No. 37 deals wlth the important subject
of component coordination with. short circuit protective devices
under short circuit conditions.
Information regard!ng 12t and I~ let-through values for
short circuit protectlve oevlces ?or a range m values of short
circuit currents is not yet available.
Because of application problems inherent when information is
incomplete, this proposal is not yet appropriate for inclusion
in the Code.
WHITE: Such practice is not prohibited by the present Code
and application problems are involved which make this proposal
inappropriate for the NEC.
WOOD: This proposal should be rejected as thls practice is
not presently prohibited by the Code. I t is improbable that the
installer will have suf~iclent information at the Job-slte to
properly implement this type of requirement.
430-40: Reject
CMP 11
SUBMITTER: Marvin T. Stevens, Greendale, WI
VKUVU3AL: 38 Revise as follows:
~F~J-O'z2RT~-.Thermal Cutouts and Overload Relays.
(a) Protection. Thermal cutouts, overload relays, and other
devices for motor-running overload protection that are not
capable of opening short circuits shall be protected by fuses or
circuit breakers with ratings or settings in accordance with
Section 430-52 or by a motor short-circuit protector In
accordance with Section 430-52.
Exception No. I: Where approved for group installation and
marked to indicate the maximum size of fuse or inverse time
circuit breaker by which they must be protected.
Exception No. 2: The fuse or circuit breaker ampere rating
shalI be permitted to be marked on the nameplate of approved
equiI~nent in which the thermal cutout or overload relay is used.
For instantaneous t r i p circuit breakers or motor short-clrcuit
protectors, see Section 430-52.
(b) Overload Relay Class Designation. An overload relay, or
the current element selection table that is provided where the
overload relay includes replaceable current elements (heaters),
shall be marked with its class designation.
Fine print note. Definition: The class designation of an
overload relay is a number that indicates the maximum time (In
seconds) in which the overload relay will function when carrying
a current equal to 600 percent of its current rating.
Fine print note. Definition: The current rating of an
overload relay is the minimum value of continuously applied
current that is expected to cause all like relays to function
(trip) under designated conditions. This value, for an
individual relay, may equal or exceed its ultimate t r i p current
under these conditions.
SUBSTANTIATION: Related proposals have been submitted (I) to
revise Section 430-34 to provide the means by which a user
selects the overload relay that has "sufficient time delay to
permit the motor to start and accelerate the load" and (2) to
add a maximum overload relay class designation to the motor
nameplate (430-7(a)). All three proposals should be considered
as a package.
The overload relay class designation system offers a way to
provide better running overcurrent protection for motors without
increasing manufacturing or installation costs.
PANEL RECOMMENDATION: Reject.
PANEL COI~IENT: Proposal is primarily a design consideration.
VUIL ON PANtL RECOMMENDATION: UnanimouslyAffirmative.
430-41-(New): Reject
CMP 11
SUBMITTER: KennethL. Paape, Allen~Bradley Co., Milwaukee, WI
PROPOSAL: 39 Add new section as follows:
~ .
Overload Relay Classes. Overload relays or
controllers which include overload relays shall be marked with
their class designation. Where a current element selection
table is furnished with the overload relays, showing the class
designation on the table shall be permitted.
SUBSTANTIATION: For many years Underwriters Laboratories had a
performance requirement in their standard for Industrial Control
(UL503) that required each overload relay to t r i p at 600 percent
of its current rating within 30 seconds. The current rating of
an overload relay is that current which when continuously
applied to the relay will ultimately cause i t to t r i p . For a
motor having a service factor of 1.0, the minimum ratio of relay
rating to motor f u l l load current permitted by Section 430-32 is
115 percent. Control manufacturers provide a table which
permits the installing electrician to select an overload relay
element and automatically comply with this requirement.
When T-frame motors became a major factor in industrial
applications, Underwriters Laboratories changed the performance
standard to 20 seconds. In order to maintain a UL listing,
control manufacturers then had to show that their overload
relays responded in not more than 20 seconds to a current equal
to 600 percent of the overload relay rating. This change was to
197
match the reduced thermal overload capability of T-frame
motors. Too many motors were burning out under locked rotor
conditions with the 30 second maximum overload relay design.
Concurrently motor manufacturers recognized that some of their
motors, particularly those associated with air conditioning and
refrigeration equipment had even shorter permissible locked
rotor time and they demanded from the control industry a line of
overload relays that were called "Fast Tripping." Meanwhile,
original equipment manufacturers and industrial users who had
high inertia loads attached to their motors realized that very
often the new 20 seconds maximum overload relay was too fast and
would t r i p out before the motor and its high inertia load came
up to speed. They needed a line of "Slow Tripping" overload
relays.
A few years ago Underwriters Laboratories, in conjunction with
representatives of the control industry, developed the concept
of class designations for overload relays. These class
designations are in the NEMAStandard for Industrial Control
(ICS-1970) and UL508. The essence of the class designation is
the maximum time (in seconds) in which the overload relay must
operate when subjected to a current equal to 600 Rercent of its
current rating. The end result is that Class 10, Class 20, and
Class 30 overload relays are available'in today's marketplace.
.Any one of them can be used for a given f u l l load motor
current. Thus for any one motor f u l l load current a user can
select any one of 3 relays, each with the same current rating,
but a different class des4gnation. Under continuous overload
conditions all 3 relays will ultimately t r i p at the current
equal to their common rating, but their response time to a
locked rotor or a longer start period is dramatically different.
Attached are the time-current characteristics of the 3 classes
of relays, each having the same maximum ultimate t r i p
characteristic permitted under Section 430-32 for a service
factor 1.0 motor. Also shown on the attachment is a tabulation
of the marked decrease in insulation l i f e as a result of
subjecting the motor windings to overtemperature. Note that
curren~ is expressed as multiples of motor full-load current,
not mu~tlples of relay ratings.
Section 430-34 recognizes the problem of bringing a motor and
its associated high inertia load up to speed by permitting an
increase in the protection factor under such conditions to 130
percent of motor full-load current for a service factor 1.0
motor. We believe that there is less danger of motor burnout
and hence a reduced f i r e hazard i f instead of moving to an
overload relay with higher ultimate t r i p current as provided by
Section 430-34, the user would select a higher class designation
overload relay. In this way he could obtain more locked rotor
time without sacrificing protection under running conditions.
We f e l t that the way to start was to add class designations
for overload relays in 2 places in the Code; f i r s t a new section
proposed as 430-41, secondly under motor marking requirements
(430-7). We f e l t that motor manufacturers and manufacturers of
motor ~iven equipment would both know the overload capability
and inertia of their equipment and thus be the most qualified to
select the class of overload relay that provides optimum
protection for the motor and yet precludes the nuisance tripping
which necessitated Section 430-34. I t was our hope that once
proposals such as we have submitted for Sections 430-7(a) and
430-41 were incorporated Into the Code, consideration could be
given to modifying Section 430-34 in some way so as to solve the
problem of nuisance tripping without sacrificing running
overcurrent protection.
PANEL RECOt~MENDATION: Reject.
PANEL COMMENT: The CMP believes that'extending the requirements
as indicated by this Proposal is not necessary as the Code now
permits this marking.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 15.
NEGATIVE: Lopez, Schram.
EXPLANATION OF VOTE:
LOPEZ: See Comment on Proposal No. 8.
SCHRAM: See explanation of negative vote on Proposal No. g.
I believe this proposal should be accepted with a revision to
add a definition of the overload relay class designation, such
as the f i r s t fine print note included in Proposal No. 38,
Section 430-40.
(2) Do not exceed device marking.
(3) Individual running overload protection conforms to Section
430-52.
However, 430-42(a) states that you Just have to apply rule (1)
and (2) (as listed above) but not (3). This is a direct
conflict. Also the overload protection as stated in Section
430-52 is essential and clearly defined in the code.
B. Section 430-42(b) basically restates rule 430-53(a)3, and
therefore is unnecessarily redundant, and should be eliminated.
C. Summary:
1. Eliminate Section 430-42(a).
2. Eliminate Section 430-42(b).
3. MoveSection 430-42(c) and (d) to 430-53.
PANEL RECOMMENDATION: Reject.
PANEL COMHENT: The Panel does not agree with the supporting
comment.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-42(b): Accept
CMP 11
SUBMITTER: A. P; White, Attleboro, MA
~ 4 2
Delete the word "running" in lines 3 and 5.
~]]~?r~I~rIATION: See A. P. White substantiation for proposal for
Diagram 430-I.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAfFirmative.
I
430-42(c): Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
~ 4 3
Delete the word "running" in lines 3 and 8.
~I]ITS'FAITTIATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
430-43: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
PROPOSAL: 44 Delete the word "running" in llne one.
~'I]I~'II~'FIATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-51: Accept
CMP 11
SUBMITTER: CMP 11
PROPOSAL: 44A Add a new sentence between second and third
~ s
of the f i r s t paragraph reading: "The devices
specified in Part D do not include the types of devices required
by-Sections 210-8 and 230-95."
SUBSTANTIATION: Officlal Interpretation No. 75-1.
PANEL RECOMMENDATION: Accept as Revised:
In Section 430-51, add a new sentence after the second
sentence of the f i r s t paragraph reading: "The devices specified
in Part D do not include the types of devices required by
Sections 210-8 and 230-95.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-52: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
~ 4 5
Delete the word "running" in lines 2 and 7.
5UBSrANIIATION: See A. P. White substantiation for proposal for
Diagram 430-I.
PANEL RECOMMENDATION: Accept as Revised:
Delete the word "running" in lines 2 and 7 of the second
paragraph only. In thSrd paragraph, line I , and in last
paragraph, line 1, insert the words "short-circuit and
ground-faul't" after the words "branch-circuit."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-42(a): Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
. ~ 4 0
Delete the word "running" in line 2.
~'I~s'rAI~rFIATION: See A. P. White substantiation for proposal for
Diagram 430-I.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
~30-52: Accept
CMP 11
SUBMITTER: TSC-Approvedfor the Purpose
PROPOSAL: 46 See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
In secona paragraph in lines 3 and 4 and also lines g and 10
(2 places) delete "and i f the combination is especially approved
for the purpose"; insert "and" in place of comma in line i ;
insert "and" between "conductor" and " i f " in llne 8; add new
sentence at end of paragraph, "An instantaneous t r i p circuit
breaker or motor short-circult protector shall be used only as
part of a combination motor controller which provides
coordinated motor branch circuit overload and short-circuit and
ground-fault protection."
Make the following additional changes in Section 430-52.
430-42(a) and (b): Reject
CMP 11
SUBMITTER: Warren Anderson, Mount Vernon, WA
PRUPOSAL: 41 Delete 430-42(a) and (b) and relocate (c) and (d)
ll-6-S'-6~-Ton 430-53.
SUBSTANTIATION:
A. 430-4Z{a} and (b) should be eliminated as i t directly
contradicts 430-53(a) and (b). 430-53(a) states three rules
that motors under I HP must follow. They are:
(1) MaximumFLC = 6 amps.
198
\
c.b. (430-52 ex: c). There i s n ' t any upper limit specified for
the other means of branch c i r c u i t protection.
In the overload range, overload relay curves better duplicate
motor damage curves and thus can be adjusted to t r i p sooner and
provide increased protection.
By allowing the instantaneous t r i p circuit breaker or motor
short c i r c u i t protector to be applied separate from the
co{nblnation controller, branch c i r c u i t short circuit and ground
fault protection will be provided by these devices, while
overload protection wlll be provided by the heaters, which are
at the load end of the branch c i r c u i t . There shouldn't be
concern over the protection of the conductors as other sections
of the Code allow up to 25 f t . of unprotected feeder taps, with
protection at the load end.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The evidence submitted is inconclusive.
vuIt ON PANEL RECOI~ENDATION: Unanimously Affirmative.
( I ) Delete third paragraph and make wording of third
paragraph Exception No. 1 to f i r s t paragraph. Delete Exception
under existing third paragraph and rearrange as new Exception
No. 2 to f i r s t paragraph, as follows: °Exception No. 2: Where
the rating specified in Table 430-152 is not sufficient for the
starting current of the motor: a. (same as (a) of existing
Exception}. b. (same as (b) of existing Exception). c. (same
as (e) of existing Exception). d. (same as (f) of existing
Exception). ~ Make new Exception No. 3 to f i r s t paragraph, same
as Item (d) of existing Exception. Make new Exception to second
paragraph as follows: "Exception: Where the setting specified
in Table 430-152 is not sufficient for the starting current of
the motor, the setting of an instantaneous t r l p circuit breaker
shall be permitted to be increased but shall in no case exceed
1300 percent of the moto~ full-load current. ~
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
430-52: Accept
CMP 11
SUBMITTER: Joseph L. Yosafat, General Electrlc Co.
~ 4 7
Add a new paragraph at end of 430-52 as follows:
"--S"~Tt-~b-le fuses shall-be permitted in lieu of devices listed in
Table 430-152 for an adjustable speed drive system provided that
the marking for replacement fuses is provided adjacent to the
fuses.
SUBSTANTIATION: Fuses now recognized by the Code for short
c i r c u i t protection for adjustable speed drives provide
inadequate protection for the drive semiconductors. As
semiconductors have very small thermal capacities, very fast
acting energy limiting fuses are ~equired.
These same fuses provide adequate short circuit protection for
other devices in the branch circuit as these other devices have
larger thermal capacities as demonstrated by short circuit
tests. These fuses are used only for short circuit protection
and are coordinated with other approved means for providing
overcurrent protection in.the adjustable speed drive system.
Marking wlll assure that the replacement fuses provide the fast
protective action required.
PANEL RECOMMENDATION: Accept as Revised:
Add a new paragraph at the end of 430-52 as follows:
For an adjustable speed drive system, special purpose fuses
for protection of semiconductors shall be permitted in lieu of
devices listed in Table 430-152, provided that:
(a) The fuse(s) is part of a controller having motor overload
and also short-circuit and ground-fault protection in each
conductor.
(b) The combination provides coordinated motor branch circuit
overload and short-circuit and ground-fault protection,
(c) Marking for.replacement fuses is provided adjacent to the
fuses.
VOTE ON PANELRECOMMENDATION:
- AFHRMATIV~: 16.
NEGATIVE: White.
EXPLANATION OF VOTE:
WHITE: Thls proposal should be rejected because i t is
incomplete and confusing. The proposed format is faulty where
i t does not include a requirement for maximum permissible fuse
rating as is done for all the other items in Section 430-52.
Additionally, there is no reason to limit this proposal ~o a
controller having overload and short circuit and ground f a u l t
protection i f the same limitations on fuse rating apply as for
nontime delay fuses in Section 430-52 and Table 430-152, since
to do so would prevent the use of other forms of overload
protection permitted in Section 430-32. The proposal woul~
therefore become unnecessarily restrictive and mandate the
addition of one form of protection even though other acceptable
protection was provided. I t was indicated during Panel
discussion that the maximum fuse rating could be specified to be
the same as for nontime delay fuses; the original proposal
should be restored with the nontime delay fuse rating limitation
added.
430-52: Reject
CMP 11
SUBMITTER: J. CannateITi, Gould Inc.
48 Changethe wording of paragraph 2 to read:
~tantaneous
t r l p circuit breaker shall be used only i f
a~justable and motor-running overload protection is provided in
each conductor. A motor short circuit protector shall be
permitted in lleu of devices listed in Table 430-152 i f
motor-running overload protection is provided in each conductor
and i f i t will operate at not more than 1300 percent off u l l - l o a d motor current.
SUBSTANTIATION: This would remove the restriction that
instantaneous trip" type circuit breakers and motor short circuit
protectors need to be in a combination controller. I t will
allow both types of devices to be f u l l y UL listed as opposed to
being Recognized Components, and be applied as separate devices.
The time'current curve represented by an overload relay and
either the instantaneous c.b. or motor short circuit protector
provides greater protection for a motor and its branch circuit
conductor than the allowed settings or ratings of inverse time
c.b. or non-time delay or time delay fuses.
Both the instantaneous c.b. and the motor short circuit•
protector have NEC specified high fault limits - 1300% for motor
short circuit protectors (430-52) and 1300% for instantaneous.
430-52: RejeCt
CMP 11
SUBMITTER: Claude E. Deering, Jr., American Petroleum Institute
PRDPOSAL: 49
Delete the words "and ground-fault" in the f i r s t
paragraph and in 'two places in the second paragraph.
SUBSTANTIATION: The wording of Section 430-52 in the 1978 Code
Is the same as in the 1975 Code. I t was changed e d i t o r i a l l y
from the 1971 Code, and the words "and ground f a u l t " were added
in three places. The present wording can be interpreted to
require special ground-fault protective devices in each motor
branch c i r c u i t .
Official Interpretation No. 75-I, dated February 18, 1975,
stated that i t was not the intent of Section 430-52 of the 1975
Code to require any form of ground-fault protective device
beyond that provided by the motor branch-circuit overcurrent
device specified in Article 430-52 of the 1971 Code. I t is
recommended that specific references to ground f a u l t protection
be eliminated from Section 430-52 to c l a r i f y the meaning, in
line with Official Interpretation No. 75-1.
PANEL RECOi~ENDATION: Reject.
PANEL COMMENT: See action on Proposal No. 44A.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
430-52, Exception Nos. 2 and 3: Reject
CMP 11
SUBMITTER: Kenneth L. Paape, Allen-Bradley Co.
~ 5 0
Add new exceptions as follows:
Exce~ion No. 2: Where the motor full-load current is less
than 3.75 amperes in a polyphase motor c i r c u i t and the motor
/ controller includes motor-running overcurrent protection in each
conductor, an adjustable instantaneous t r i p c i r c u i t breaker, not
as part of a combination motor controller, shall be permitted to
serve as the short-circuit and ground-fault protective device,
providedthe length of the conductors between the instantaneous
t r i p circuit breaker and the motor controller does not exceed 25
feet, and the conductors are suitably protected from physical
damage.
Exception No. 3: Where the motor full-load current is' less
than 3.75 amperes in a polyphase motor c i r c u i t , the rating of an
inverse tlme circuit breaker shall not exceed 400 percent of the
full-load current.
SUBSTANTIATION: Section 430-52 requires that the setting of an
instantaneous t r i p circuit breaker shall in no case exceed 1,300
percent of motor f u l l load current. Hence the worst case
condition permitted by Exception No. 2 proposed above would be
an instantaneous t r i p circuit breaker set for 48.62 amperes to
protect a motor with ~ full-load current of 3.74 amperes, Where
the full-load current is less than 3.74 amperes, the maximum
permissible t r i p s~tting is proportionally less. Motor c i r c u i t
conductors for motors having a full-load current of less than
3.75 amperes have ampacities not less than 15. (Table 310-16
specifies 15 as the minimum ampacity of #14 AWG wire and 21 as
the ~npacity of #18 AWG wire, the latter shown only for 90
degrees Celsius insulation.)
The current elements (heaters) for overload relays usually
used to provide motor running overcurrent protection in
polyphase motor circuits have a resistance inversely
proportional to the square of their current rating. Thus the
lower the motor full-load current, the higher the resistance of
the current element.
The smallest standard rating of an inverse time circuit
breaker is 15 amperes. Inverse time circuit breakers rated 15
amperes t r i p instantaneously at approximately 105 amperes or
more,
As the resistance of the current elements in the circuit
increases, the magnitude of any fault which can be produced on
the load side of the elements decreases to.the point where i f a
short-clrcuit occurs in a 240 volt system supplying a motor with
a full-load current of one ampere or less, the maximum
fault current is not sufficient to activate the instantaneous
t r i p mechanism of an inverse time circuit breaker, r~gardless of
the short-circuit current available at the line terminals of the
circuit breaker. For every supply voltage and any fault current
available at the circuit breaker line terminals, there is some
overload relay current element appropriate for the motor
full-load current where there is no instantaneous tripping
action by'a 15 ampere inverse time circuit breaker possible,
because of the element's resistance. A f a u l t current greater
199
than 1,300 percent of motor full-load current that is not
sufficient to t r i p an inverse" time circuit breaker
instantaneously subjects the overload relay element to a current
beyond its limit of self protection and the element burns open
before the inverse time portion of the circuit breaker can cause
the breaker to t r i p . When the current element burns open i t
arcs and usually causes a new short-circuit within the
controller enclosure. This second short-circuit is now not
limited by the resistance of the current element and the circuit
breaker now responds instantaneously, but only after the
overload relay has been severely damaged.
Adjustable instantaneous t r i p circuit breakers rated less than
15 amperes are commercially available, some with t r i p settings
as low as 7 amperes. By using instantaneous t r i p circuit
breakers in lieu of inverse time circuit breakers in motor
circuits where the full-load current is less than 3.75 amperes,
immediate instantaneous trip action by the circuit breaker can
be obtained. The risk involved in having up to 25 feet of
conductors between a separately mounted instantaneous t r i p
circuit breaker and its associated motor controller protected
against short circuit and ~round faults at not mere than 324
percent of their mnpacity tworse case is 48.62/15 : 3.24} is
less than the 333 percent permittedfor transformer feeder taps
by Exception No. 8 under Section 240-21..
The wording of proposed Exception No. 3 is such that i t should
encourage development and a v a i l a b i l i t y of polyphase inverse time
circuit breakers that are rated less than 15 amperes and have
time versus current-to-trip characteristics lower than those for
inverse time circuit breakers rated 15 amperes. When such
circuit breakers are available, they could be recognized as
standard sizes in Section 240-6.
Note that this proposal would not restrict the use of 15
ampere inverse time circuit breakers in single phase motor
circuits.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirement is necessary. The Panel
belleves that extending the requirements as intended by this
Proposal is not appropriate at this time.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
I
430-53(b): Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
~ 5 4
Delete the word "running" in line 4.
~I]ITS'TAI~FIATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept as Revised:
Add to proposal - In line 1 and line 6 insert the words
"short-circuit and ground-fault" after the words
"branch-circuit."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-53(c): Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
PROPOSAL: 55 Delete the word "running" in lines 2 and 3.
~I]I~TTTI]TTIATION: See A. P. White substantiation for proposal for
Diagram 430-1
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
430-53(c)(1):
Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
PROPOSAL: 56 Delete the word "running" in line one.
~'UI~S'TAITTIATION: See A. P. White substantiation for proposal for
Diagram 430-I. PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-53(c)(3):
Reject
CMP 11
SUBMITTER: Alton R. Thompson, Durham, NC
]~-O-PO-~A
' -L-~." 57 Revise as follows:
~ a c h
circuit breaker is.of the inverse time type and, i f
rated more than 60 amperes, 'Is approved for group installation.
SUBSTANTIATION: When fuses are required, especially on
resldent~al a/c units, a raintight pull out or a raintlght
switch is used. With a raintight pull out a child can put a
screwdriver or a small piece of conducting material into the
pull out and get a lethal shock. With a raintlght switch a
child can get his whole hand in the switch and get a lethal
shock. We are trying to protect small component parts and
forgetting our small friends who do not know any better than to
open a l i d on a switch. In my own experience of 10 years of
electrical contracting and specializing in air conditlon.and
refrigeration inst~llations, I used inverse time circuit
breakers with desirable results.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necesslty.
VOTE ON PANELRECOMMENDATION:
AFFIR~t~TIYE: 14.
NEGATIVE: Cannady,White.
NOT VOTING: Aquilino.
EXPLANATION OF VOTE:
AQUILINO: Conslderable test data has been presented both for
and ~gainst this proposal. In view of the conflicting data, and
lacking the f a c i l i t i e s to confirm the test results myself, I do
not feel there is sufficient Justification for either an
affirmative or negative vote at 'this time.
CANNADY: I vote against rejecting this Proposal because we
have seen very strong evidence that circuit breakers are doing a
better Job than fuses in limiting current, interrupting and
protecting circuits. I feel that to reject this is
discriminating against circuit breakers ~nd showing preferential
treatment to fuses.
" WHITE: The proposal was shown to be valid by the UL
Fact-Finding data and information provided to the Panel on
performance of circuit breakers and fuses in that the same level
of performance is provided as presently specified.
430-52, Exception No. 2-(New): Reject
CMP 11
SUBMITTER: Idaho Chapter IAEI
51
In Section 430-52 change "Exception" to
~l~-~-~-t-fon No. i . " Add a new Exception No. 2.
Exception No. 2: The values given in Table 430-152 shall not
apply to adjustable speed drive motors when the power conversion
equipment provides overload protection for the motor.
Additional protection is not then required.
SUBSTANTIATION: Section 430-52 does not address short-circuit
and ground-fault protection for the branch circuits of D.C.
motors on the load side of power conversion equipment for .
adjustable speed drives. Section 430-2 Adjustable Speed Drive
Systems in the f i r s t paragraph, second sentence, gives much
inferred requirements. This sentenceshould be deleted from
Section 430-2 and moved to Section 430-52 where i t belongs. In
the field some manufacturers of adjustable speed drive equipment
are providing neither overload or short-clrcuit and ground-fault
protection for the D.C. motors and branch circuit conductors.
This requirement should b~ clarified in the proper section of
the Code.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel's action on Proposal Nos. 5 and 47,
Sections 430-2 and 430-52.
VOTE ONPANEL RECOMMENDATION: UnanimouslyAffirmative.
430-53(a): Accept
CMP 11
SUBMITTER: TSC-Nominal Voltage
I~TO]~-O-~L-T•. 52 Revise the text as follows:
"Several motors each not exceeding one horsepower in rating
shall be permitted on a nominal 120 volt branch circuit
protected at not over 20 amperes or a branch circuit of 600
volts, nominal, or less protected at not over 15 amperes, i f all
of the following conditions are met:"
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-53(c)(3), Exception-(New): Reject
CMP 11
SUBMITTER: R.B. Boyd, Jr., Raleigh, NC
58 Add exception as follows:
~ i o n :
Each circuit breaker is of the inverse time type
and, i f rated more than 60 amperes, is approved for group
installation.
~q
SUBSTANTIATION: For many years we have treated single phase,
Z50 volt window air-conditioning units as a single motor load
and permitted branch circuit overcurrent protection to consist
of either time limit or inverse time circuit breakers. As far
as can be determined, f i e l d experience using such breakers rated
at 50 amperes and less has been good. I f this information is
correct, then why not permit the smaller inverse time circuit
breakers to be used on residential and small commercial branch
circuits within the prescribed limits. Also many such fixed
installations have been and are being accepted and f i e l d reports
do not indicate d i f f i c u l t i e s resulting from the use of smaller
inverse time circuit breakers.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necesslty.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-53(a)(3): AcE~pt
CMP 11
SUBMITTER: A. P. WHite, Attleboro, MA
;I}ITOI~OSAIZ-T. 53 Delete the word "running."
~]B-S"FAI~I'IATION: ,See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept as Revised:
Add to proposal - In paragraph (a)(2) insert the words
"short-clrcuit and ground-fault" after the words
"branch-clrcuit."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
200
20 ampere overcurrent protective device against some high
impedance faults within the overcurrent devices rating or when
hlgh short-circult currents are available. As written, this
proposal violates 110-10 and 240-1 of the NEC. Also, circuit
transformers cannot be protected by secondary control.circuit
protection. A control transformer should have the same
protection in a motor controller enclosure as well as any other
enclosure. Control transformers should be protected as required
in Article 450. Control transformers are a big source of f i r e
since the primary protection is usually much too great to
provide any protection.
430-53(d): Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, HA
~I~TOPO'S'AL-~.sg Delete the word "running" in line 8.
SUBSTANTIATION: See A. P. White substantiation for proposal for
Diagram 430-I.
PANEL RECOMMENDATION: Accept as Revised:
I Add to proposal - In llne 3 insert the words "sho~t-circuit
and ground-fault" after the words "branch-circuit."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-55: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
, I ~ 6 0
Delete the word "running" in lines 2 and 4.
~:I]I~"~¢~IATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-71(b)-(New): Reject
cMP 11
SUBMITTER: A. C. Clark, Manufacturing Chemists Assn.
PROPOSAL: 64 Add new (b) as follows:
~onductor
size. Motor control circuit cofiductors shall
be sized in accordance with Section 310-5.
Exception:' Where the motor control conductors are smaller
than No. 14, the provisions of Article 725 shall apply.
SUBSTANTIATION: .To correlate with companion proposal for new
Exception No. 5 to Section 430-72(a). (See that proposal for
additional"substantiation.) Changewill also correlate with
proposed addition of, Section 725-2(e).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See action on Proposals Nos. 63 and 65.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-59-(New): Reject
CMP 11
SUBMITTER: J. M. Rice, Allen-Bradley Co.
61 Add new 430-59 as follows:
~r~o-:5"~]~-'. Interrupting Rating. Every overcurrent protective
device installed in a polyphase motor circuit where the voltage
to ground exceeds250 volts shall be marked with an interrupting
rating.
SUBSTANTIATION: Section 240-83(c) requires that circuit
breakers be marked with their interrupting rating only i f i t is
other tha~ 5,000 amperes. Section 240-60(c) requires that fuses
be marked with their interrupting rating only i f i t is other
than 10,000 amperes. At locations where polyphase power is
supplied to motors at 480 and 600 volts there is high
probability that the fault current avallable will exceed 5,000
amperes. Manywill exceed 10,000 amperes.
By requiring an interrupting rating to be marked on the
overcurrent protective device there is an automatic reminder to
the installer to consider the fault current available at the
point of installation. Our company is aware of two cases in the
past year where a serious fault occured in an industrial
application and the overcurrent protective device did not clear
the fault successfully. In both cases personnel were injured.
We should not overlook an opportunity to add a requirement to
the Code that will focus attention on the need to have
overcurrent protective devices with interrupting ratings equal
to or exceeding the fault current available.
PANEL RECOMMENDATION: Reject.
PANEL C~ENT: Panel feels subject is adequately covered.
VOTE ON PANELRECOI~MENDATION:
AFPIRMJ~IIV~: 16.
NEGATIVE: Gubany.
"'
EXPLANATION OF VOTE:
GUBANY: I am voting negative on Panel rejection since I agree
with the author's supporting comment. This proposal will
enhance compliance with 110-9 and 110-10.
430-72: Accept
CMP 11
SUBMITTER: TSC-Control Circuit Protection
PROPOSAL: 65 Revise as follows:
~ .
Overcurrent Protection.
(a)' General. ,A motor control circuit tapped from the load
side of a motor branch-circuit short-circuit and ground-fault
protective device(s) and functioning to control the motor(s) ,
connected to that branch-circult shall be protected against
overcurrent in accordance with Section 430-72. Such a tapped
control circuit shall not be considePed to be a branch-circuit
and shall be permitted to be protected by.either a supplementary
or branch-circuit overcurrent protective device(s). A motor
control circuit other than such a tapped ~ontrol circuit shall
be protected against overcurrent in accordance with Section
725-12 or 725-35, as applicable.
(b) Conductor Protection.
(1) Conductors larger than No. 14 shall be protected
against overcurrent in accordance with their ampacities. The
ampacities for control circuit conductors No. 14 and larger
shall be those given in Tables 310-16 through 310-19, without
derating factors, and the limitations of Section 310-1 shall not
apply.
(2) Conductors of Nos. 18, 16 and 14 shall be considered as
protected by an overcurrent device(s) of not more than 20
amperes rating.
Exception No. 1 for (I) and (2} above: Conductors which do
not extend beyond the motor control equipment enclosure shall
be considered as protected by the motor branch-clrcuit
short-circuit and ground-fault protective device(s) where the
rating of the protective device(s) is not more than 400 percent
of the ampacity of the control circuit conductors for conductors
No. 14 and larger; or not more than 25 amperes for No: 18 and 40
amperes for No. 16. The ampacities for conductors No. 14 and
larger shall be the values given in Table 310-17 for 60 C
conductors.
Exception No. 2 for (1) and (2) above: Conductors of No. 14
and larger which extend beyond the motor control equipment
enclosure shall be considered as protected by the motor
branch-clrcuit short-circuit andground-fault protective
device(s) where the rating of the protective device(s) is not
more than 300 percent of the ampacity of the control circuit
~onductors. The ampacities shall be the values given in Table
310-16 for 60 C conductors.
Exception No. 3 for (1) and (2) above: Conductors supplied~by
the secondary side of a single-phase transformer having only a
2-wire (single-voltage) secondary shall be considered as
protected by overcurrent protection provided on the primary
(supply) side of the transformer, provided this protection is in
accordance with Section 450-3 and does not exceed the value
determined by multiplying the secondary conductor ampacity by
the secondary-to-primary voltage ratio. Transformer secondary
conductors (other than 2-wire) are not considered to be
protected by the primary overcurrent protection.
Exception No. 4 for (1) and (2) above: Conductors of control
circuits shall be considered as protected by the motor
branch-clrcuit short-circult and ground-fault protective
device(s) where the opening of the control circuit would create
a hazard, as for example, the control circuit of a f i r e pump
motor, and the like.
(c) Control Circuit Transformer. Where a motor control
circuit transformer is provided, the transformer shall be
protected in accordance with Articl~ 450.
Exception No. 1: Where the control circuit transformer is an
integral part of the motor controller and is located within the
motor controller enclosure, and where an ov~rcurrent device(s)
rated or set at not more than 200 percent of the rated secondary
current of the transformer Isprovided in the secondary circuit.
430~52(b): Reject
CMP 11
SUBMITTER: Robert J. Cunningham, Duquesne Light Company
l~ITOl}l~TAt-~ 62 Add a second paragraph, requiring numbering
exlstlng paragraph as follows:
(b) Future Additions
(1) Existing unnumbered paragraph.
(2) When a motor feeder ampacity is oversized by a
specific growth factor in amperes this growth factor shall be
added to "the sum of the full-load currents of the other motors
of the group" in Section 430-62(a) when determining the feeder
protective device rating.
SUBSTANTIATION: The purpose of Part E is to allow the ratings
of the protective devices on motor feeder circuits to be higher
than the conductor ~npacity so that locked rotor current will
not cause nuisance operation of the protective device during
motor starting. When growth factors are designed into a motor
feeder i t is intended that motors will be added to utilize this
capacity. This proposal will allow the feeder protective device
to be selected for the intended load, eliminating future
nuisance operations and costly protective device changes,
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
i
430-71(a): Accept
CMP 11
SUBMITTER: TSC-Control Circuit Protection
PROPOSAL: 63 Delete second paragraph of Section 430-71(a).
~]~'~'AI~I'IATION: Provision covered in TSC Proposal No. 4 for
~evislon of Section 430-72. See 430-72(a).
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Gubany.
EXPLANATION OF VOTE:
GUBANY: I am voting negative on Panel acceptance since i t can
be proven that No. 16 and No. 18 wire cannot be protected by a
201
Exception No. 2: Where the transformer supplies a Class 1
power-limited, Class 2 or Class 3 remote control circuit
conforming,with the requirements of Article 725.
Exception No. 3: Where protection~is provided by other
approved means.
\
Exception No. 4: Overcurrent protection shall be omitted
where the opening of the control circuit would create a hazard,
as for example, the control circuit of a f i r e pump motor, and
the like.
SUBSTANTIATION: For coordination of control circuit
requirements. The intent is to apply Section 430-72 to all
portions of a control circuit tapped from a motor branch
circuit, and to apply Article 725 in all other cases, as
specified in Section 430-72(a). Other than editorial changes,
the following relates proposed revised Section 430-72 to the
1978 NEC and other TSC proposals.
430-72(a) To coordinate with Article 725, as stated above.
See" also TSC Proposal No. 5 for new Section 725-2(e).
430-72(b) (1) - Coordinates provisions from second paragraph,
of Section 430-72(a) of 1978 NEC with Section 725-12(a).
430-72(b) (2) - Permits No~. 18 and 16 control circuit
conductors and coordinates with Section 725-12(b).
430-72(b), Exception No. 1 - Equivalent to Section 430-72(a),
Exception No. 1 in 1978 NEC. The values of 25 amperes for No.
18 and 40 amperes for No. 16
conductors are based on 400 percent of ampacities of 7 and 10
amperes respectively, as specified in Table 400-5, and reflect
recognized practice. Reference to Table 310-17 reflects
recognized practice.
430-72(b), Exception No. 2 - Equivalent to Section 430-72{a),
Exception No. 2 in 1978 NEC.
, 430-72(b), Exception No. 3 - Equivalent to Section 43eO-72(b),
Exception No. I in 1978 NEC. Sameas Section 240-3, Exception
No. 5 with word "only" preceding "a 2-wire (single-voltage)
secondary. . . . " for clarification of intent. See also TSC
Proposal No. 7 for new Section 725(a) and (b), Exception No. 3.
430-72(b), Exception No. 4 - Equivalent to Section 430-72(a),
Exception No. 4 of 1978 NEC.
430-72(c) - To coordinate with Article 725. See TSC Proposal.
No. 9 for new Section 725-12(c).
430-72(c), Exception No. I - Similar to Section 430-72(b) in
• 1978 NEC but restricted to (1) control circuits tapped from
motor branch-circuit and (2) transformers integral with motor
controller where transformer primary is within controller, not
field-wired.
430-72(c), Exception No. 2 - Equivalent to Section 430-72(b),
Exception No. 2 in 1978 NEC. Coordinates with Article 725.
430-72(c), Exception No. 3 - Same as Section 430-72(b),
Exception No. 3 in 1978 NEC.
430-72(c), Exception No. 4 - Equivalent to Section 430-72(b),
Exception No. 4 in 1978 NEC.
PANEL RECOfC4ENDATION: Accept as Revised:
In Section 430-/Z[b)(1) of the Proposal, second sentence,
a f t e r "ampacities" delete the words "for control circuit
:conductors No. 14 and larger."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Gubany.
EXPLANATION OF VOTE:
GUBANY: I am voting against the Panel's acceptance for the
same reasons as for Proposal No. 63.
case of small conductors forming an integral part of electronic
controls.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See action on Proposals Nos. 63 and 65.
VOIE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-72(a) Exception No. 5-(New): Reject
CMP 11
SUBMITTER: A. C. Clark, Manufacturing Chemists Assn.
~
l TO$RZTSSTL-~.68
Add a new exception as follows:
~ i o n
No. 5: Where the motor control circuit conductors
are smaller than No. 14, overcurrent protection shall be in
accordance with Article 725.
SUBSTANTIATION: Correlates with proposed additions of Sections
430-.IZ(b} and 725-2(e).
Contrary to published reports, not all remote control circuits
must comply with Article 725. Motor-control circuits are an
exception to Article 725 unless they cannot be described without
empSoying any of the considerations given t6 remote control
circuits in Article 725.
The attached problem and analysis* indicates the typical
confusion that users face in deciding on the applicability of
Article 430F vs. Article 725. Since #14 copper and larger motor
cntrol circuits do not meet the parameters of Article 725 and
are covered elsewhere in the Code, as indicated in the problem
analysis, confusion will be reduced by stating in Article 430F
where Article 725 is applicable.
*Attachment has been supplied to CMP members.
PANEL RECOMMENDATION: Reject.
PANEL COMMENt: See action on Proposals Nos. 63 and 65.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-72(b): Reject
CMP 11
SUBMITTER: Paul Hoh, Bussmann Mfg.
PROPOSAL: 69 Revise as follows:
-~hen
a motor control circuit transformer is provided i t
shall be protected according to Section 450-3.
SUBSTANTIATION: Control transformers are a potential f i r e
hazard whether they are a motor control transformer or a control
transformer for other type(s) of equipment. Control
transformers should be protected in compliance with 450-3. The
same level of protection should be afforded control transformers
for motor control.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necesslty.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 15.
NEGATIVE: Gubany, Kish.
EXPLANATION OF VOTE:
GUBANY: I am voting negative on Panel's rejection since I
support the author's reasoning that control transformers should
be protected asper Article 450. The transformer does not know
where i t i s located. I t should be protected on the primary as
required in Article 450.
Control transformers are a big source of equipment f i r e .
Sooner or leter the transformer will break down and should not
result in a f i r e .
I t can be easily demonstrated that a shorted primary or
secondary willcause ignition.
KISH: A transformer should be protected according to Section
450-3 and we should not make an exception without Justification.
-
l
430-72(a): Reject
CMP 11
SUBMITTER: Joseph L. Yosafat, General Electric Co.
~ 6 6
In the second paragraph, before the last three
~ h a l l
not apply" add the words "regarding ampacities."
SUBSTANTIATION: The purpose of this proposal is to c l a r i f y the
requirement that only the ampacities stated in Article 310 are
• applicable to the conductors of control circuits within an
enclosure. I t is possible to interpret the present wording to
mean that all requirements of Article 310, such as minimum size
of conductors, are applicable.
PANEL RECOMMENDATION: Reject.
PANEC COMMENT: See action on Proposals Nos. 63 and 65.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative. I
430-86(a): Reject
CMP 11
SUBMITTER: Robert G. MacManus, Pawtucket, RI
PROPOSAL: 70 Delete Section 430-86(a).
~'I]I~S"IS~IATION: Section 430-86(a) allows the motor and driven
machinery to be out of sight from the controller location i f the
controller disconnecting means is capable of being locked in the
open position. A similar condition existed with Section 430-102
previous to the 1965 NEC, but the words "or be arranged to be
locked in the open position" was omitted from the 1965 NEC
apparently because of a hazard to a man working on the
controller. Since the same hazard exists when the motor and
driven machinery are out of sight from the controller location,
there seems to be an apparent contradiction between Section
430-86 and Section 430-102.
PANEL RECOI~ENDATION: Reject.
PANEL.COMMENT: The Panel does not agree with the supporting
comment.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Wood.
EXPLANATION OF VOTE:
WOOD: I am votlng negative on this proposal since I agree
with the Panel's original recommendation to accept as revised.
."Delete Sections 430-86(a) and (b). Section 430-86 to read:
Motor not in Sight from Controller. Where a motor and the
driven machinery are not in sight from the controller location a
manually operable switch that will disconnect the motor from its
source of supply shall be placed within sight from the motor
location. FPN to remain in Code."
430-72(a), Exception No. 1 and (b),
Exception No. 5: Reject
CMP 11
SUBMITTER: Joseph L. Yosafat, General Electric Co.
PROPOSAL: 67 At the end of (a) Exception No. 1 add, "except
rating or setting of the overcurrent protective
device(s) shall not be required to be smaller than 15 amperes."
Add a new Exception No. 5 to (b) as follows:
Exception No. 5: The rating or setting of the overcurrent
protective device(s) shall not be required to be smaller than 15
amperes.
SUBSTANTIATION: Tables 310-16 through 310-19 do not show
ampacltles less than 15 amperes. Conductors having ampacities
less than 15 amperes, but not less than one-quarter of this
value, are protected to the same degree as is permitted by
Exception No. 1 under 430-72(a).
The present requirement is particularly impractical in the
202
'
the exception i s required.
Further Supporting Comment, Not for inclusion in "Preprint":
The loophole created by this lack of positive definition of
"portable" has been taken advantage of by a major electrical
manufacturer with extensive Code representation, to the extent
that hazards to its e~oloyees are greatly increased. (One lost
an arm, largely because of non-lockability of cord and plug.)
This company looks on "portable" with the example illustrated by
Webster, and its legal representatives defend this position on
that basis. I t cites legal references to "portable cranes" as
an example of use of this word. On this basis, even an electric
locomotive could be considered as "portable."
PANEL RECOMMENDATION: Accept as Revised.
For a cord- and p]ug-connected motor an attachment plug and
receptacle having ratings no less than the motor ratings shall
be permitted to serve as the disconnecting means. A horsepower
rated attachment plug and receptacle shall not be required for a
motor rated 2 horsepower or less.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Schram.
EXPLANATION OF VOTE:
SCHRAM: A negative vote is cast to draw attention to the fact
that receptacles and attachment plugs rated over 60 amperes may
be marked "For Disconnect Use Only" and not be rated or intended
for current interrupting. Also, attachment plugs and
receptacles rated 60 amperes or less are tested at 150 percent
of rating. Since we believe the intent of Exception No. 5 was
to permit the plug and receptacle to be the disconnect means for
cord- and plug-connected appliance only, in accordance with
Article 422, we recommend consideration of the following for the
second sentence of the Panel Recommendation.
"A horsepower rated attachment plug and receptacle shall not
be required for a cord- and plug-connected appliance in
accordance with Section 422-22.
430-87, Exception: Accept
CMP 11
SUBMITTER: TSC-Nomlnal Voltage
~ROI~}~'AL~T. 71 Change "For motors of 600 volts or less . . . . " to
l ~ r
motors rated 600 volts or less . . . . "
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nomlnal Voltages.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously A f f i r m a t i v e .
430-101 FPN-(New): Reject
CMP 11
SUBMITTER: Idaho Chapter IAEI
I~lTOPO-S']~L-~.'72
Add a third fine print note following Section
See Section 110-23 for disconnecting means for controllers
used to control loads other than motor loads.
SUBSTANTIATION: To cross reference that a disconnect is
requlred In slght from all controllers that serve to govern
electrical power. (See proposal for new Section 110-23
Disconnecting Means for Controller.)
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Outside the scope of Panel 11.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
430-102, Exception No. i: Reject
CMP 11
SUBMITTER: Joseph L. Yosafat, General Electric Co.
~ 7 3
Revise as follows:
~ i o n
No. i: The controller disconnecting means shall be
permitted to be out of sight of the controller, provided that
the controller is marked with a warning label giving the
location and identification of the disconnecting means. The
controller disconnecting means shall be capable of being locked
in the open positio6.
SUBSTANTIATION: The exception permitting the disconnecting
means to be out of sight of the controller i f i t is lockable in
the open position is equally safe for motor circuits under 600
volts as well as for other controller circuits. Elimination of
the "motor circuits over 600 volts" limitation will make this
section more compatible with Section 430-86(a).
This amendment would provide safety benefits in many
industrial f a c i l i t i e s by permitting grouping of various
disconnecting moans in an electrical room wherein maintenance is
penformed by qualified personnel. I t also minimizes electrical
equipment in areas where unqualified personnel are permitted to
work.
•
PANEL RECOMMENDATION: Reject.
PANEL C{X4MENT: The Panel does not agree with the supporting
comment.
VOTE ON PANELRECOMMENDATION:
AFFIRMAIIVE: lb.
NEGATIVE: Mierendorf.
EXPLANATION OF VOTE:
MIERENDORF: The requirements of Proposal No. 73 to provide a
warning label and locking means when the controller
disconnecting means is out of sight of the controller is
considered to be of less danger to personnel than relying on the
disconnecting means being "in sight of" the controller.
In multi-motor installations, many switches look alike and
could easily lead to confusion when trusting to an "in sight of"
situation.
Another indirect undesirable consequence of rejection of this
proposal is the possibility of controllers being located in
undesirable environments, with attendant risks of malfunction in
order to have the associated disconnect moans located "in sight
of" the controller.
430-110(c)(1):
Reject
CMP 11
SUBMITTER: J. J. Kark, National Electrical Manufacturers
~ o n
PROPOSAL: 75 Changethe reference to "Table 430-151" in third
paragra--~-~h to read "Table 440-XX."
SUBSTANTIATION: See NEMAProposal on Table 430-151.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Proposal No. 85A.
VOTE ONPANEL RECOMMENDATION: Unanimously Affirmative.
430-110(c)(I), Exception: Accept
CMP 11
Secretary's Note: I t was the action of the Correlatin'g
Committee that the Panel review the Recommendation to c l a r i f y
the use of "shall be permitted to be" and the units to be
compared.
SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration
T ~
PROPOSAL: 76 Revise as follows:
~ i o n :
Where part of the concurrent load is resistance
load, and where the disconnecting means is a switch rated in
horsepower and amperes, the horsepower rating of the switch "is
permitted to be" not less than the combined load of the
motor(s), "provided" the ampere rating "is" not less than the
locked-rotor current o f the motor(s) plus the resistance load.
SUBSTANTIATION: Change is for permissive wording. Section
430-110(c)(1) provides for adequate rating of disconnect without
application of exception. When motor load is small with respect
to resistance heater load, exception may permit lower adequate
rating of disconnect; however, when motor load is larger with
respect to resistance heater load, application of exception
could result in higher rating of disconnect than necessary.
PANELRECOIeJ4ENDATION: Accept as Revised:
Exception: Where part of the concurrent load is resistance
load, and where the)disconnecting means is a switch rated in
horsepower and amperes, the horsepower rating of the switch
shall be permitted to be not less than the combined load of the
motor(s), i f the ampere rating of the switch is not less than
the locked-rotor current of the motor(s) plus the resistance
load.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
430-109, Exception No. 5: Accept
CMP 11
SUBMITTER: Ralph H. Lee, Lee Electrical Eng., Inc.
~ 7 4
Revise as follows:
---E'R'Ce~ion No. 5: For motors of portable appliances rated at 2
horsepower or less and 300 volts or less, an attachment plug and
receptacle having ratings no less than the motor ratings shall
be permitted to serve as the disconnecting means.
SUBSTANTIATION: This proposal is intended to c l a r i f y a
condltlon presently misinterpreted in Code application. For
example, a "portable motor" is interpreted, even in legal
actions, as one which is movable, even by use of powered
hoisting apparatus, such as fork l i f t trucks, and weighing a ton
or more. This is patently beyond the intent of the Code, which
intended "portable" to accompany the definition of "Appliance,
Portable: which is actually moved or can easily be moved--in
normal use." Thls'indicates that the appliance may be moved
while in use, such as a portable electric d r i l l , saw, vacuum
cleaner, concrete finisher or the like, not.a piece of equipment
weighing a ton or more and movable only with powered hoisting
equipment.
This rewording and limit o~the exception is in general
agreement with Exception 2, especially in view of the control
device being separate from the disconnecting means.
Lacking a direct definition for "portable," reference must now
be made, by some parties, to Webster, which includes as an
example, "a portable schoolhouse." To prevent misuse with the
attendant hazards, positive definition of the intended scope of
430-113, Exception No. 2-(New): Reject
CMP 11
SUBMITTER: A.C. Clark, Manufacturing Chemists Assn.
PRDPOSAL: 77 Add exception as follows:
~ i o n
No. 2: In industrial establishments only, where
conditions of maintenance and supervision assure that only
qualified persons will service the installed motor and
motor-operated equipment, all disconnecting means shall be
permitted to be remotely located provided the disconnecting
means for other than control and signal devices is capable of
being locked in the open position.
SUBSTANTIATION: In industrial establishments, the term
motor-operated equipment sometimes covers such a broad scope as
to make the provisions of Section 430-113 overly restrictive.
For example, an extruder is a piece of motor-operated equipment
that consists of a motor drlve and several sectlons of electrlc
203
heaters around the extruder barrel. Established industry
practice has been to use motor and heater disconnects that are
remotely located and capable of being locked open. Section
430-113 now prohibits this.
A second example of motor-operated equipment is a motor driven
conveyor with photocell sensors along the conveyor. For these
photocells there is no safety need to require a local disconnect
for these photocells.
Established industry practlce has been to
use disconnects that are remotely located. These remote
disconnects are often contained in a panelboard and are
generally of the non-lockable type.
A motor i t s e l f often contains RTD's, thermistors, or switches
within the motor housing. Established industrial practice has
been to use only remote disconnects for these sensors.
Industrial establishments have followed the above established
practices for years and have achieved an excellent safety record
where the equipment is serviced by qualified personnel. For
such reasons, Section 430-113 is overly restrictive and should
be changed by the proposed Exception 2.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Present requirement is necessary.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Dye.
EXPLANATION OF VOTE:
DYE: I contend that operator safety is jeopardized as the'
Code now stands requiring disconnect switches adjacent to the
motor or motor operated equipment for each source of energy.
In the f i r s t place the .number of switches required would block
the operator's view of the process especially in multi-motor (up
to 100 or more motors per line) processes such as steel, auto,
chemical, and paper.
In the second place the danger to an operator of pulling a DC
f i e l d switch on a DC motor or a synchronous motor is great. I t
would also be dangerous to the operator i f he pulled the
disconnect switch on safety devices such as pressure,/flow, zero
speed, o~ photocell switches.
The hostile operating floor environment ( o i l , d i r t , corrosive
chemical, and hazardous atmospheres) that these switches would
be located in will lead to early failure. This is a hazard to
operators from an electrical energy release and from
malfunctions of safety devices.
430-113, Exception No. 2-(New): Accept
CM~ 11
SUBMITTER: Alton R. Thompson, Durham, NC
l~TO]~I~SKL-T.'78 Add~anexception as follows:
---E'x~e-p~-ion-No. 2: A separate disconnecting means shall not be
required for a Class I I or Class I l l remote-control circuit of
50 volts or less.
SUBSTANTIATION: This would resolve a lot of problems in the
f i e l d where now a disconnect is required. Class 2 and Class 3
circuits of 50 volts or less would not create a shock hazard,
f i r e hazard, or a mechanical hazard. This exception is needed
to clear up confusion by specifically permitting what is
generally being excepted.
PANEL RECO~IENDATION: Accept as Revised:
Change "Class I I and Class I l l " to "Class 2" and after
" c i r c u i t " change the rest of the sentence to read "conforming
lwith Article 725, rated not more than 30 volts and which is
~isolated and ungrounded."
I Changeexisting exception to Exception No. i and add the
Iproposed exception as Exception No. 2.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ANANIAN: My reason for voting affirmative on the proposal is
that i t provides some r e l i e f relative to alleviating the
necessity to supply immediately adjacent disconnects for some
Class 2 circuits used in control and monitoring systems.
However, in my voting affirmative to reject Proposal No. 77, I
feel this proposal should be expanded to include the following
additional exceptions:
Exception No. 3: External interlock control circuits and
monitoring circuits operating at less than 150 volts need not be
disconnected provided that the circuit conductors are grouped,
identified and covered and a warning "label is attached adjacent
to the equipment enclosure disconnect(s) identifying the source
and location of the interlock contacts and monitoring circuits.
Exception No. 4: Separately excited synchronous and direct
current motors need not have their field circuits disconnected
provided that a warning label is attached adjacent to the f i e l d
terminal box identifying the location of the remote source
disconnecting means capable of being locked in the open position.
My substantiating comments for proposing to add Exceptions No.
3 and No. 4 are:.
Section 430-113, as written, is so broad and far reaching as
to be impractical.
For example, the term "energy," unless
defined as to magnitude and potential, would include any device
such as thermo-couple outputs which potential is in millivolts
creating no hazard. Also included would be telemetering
circuits, proximity switch outputs, sensor outputs, dry safety
control interlock contacts, etc. In an integrated process or
highly automated assembly or manufacturing operation, a central
control system could have many sources of energy. I t would be
highly impractical and essentially not feasible to provide
disconnects on ali of these sources. Greater hazards would be
created in the event ~hat a safety interlock were l e f t open
after servicing the equipment. The switch could f a i l or become
inoperative due to a loose wire or contamination resulting in
the opening of a critical interlock circuit which may result in
extensive damage to a process or create an explosion hazard. In
hazardous areas, explosion-proof switch devices would need to be
added, increasing the hazard potential in these areas. As more
terminations and switches are added, r e l i a b i l i t y decreases.
Industry has been operating for decades without providing
immediately adjacent disconnecting means from each source of
electrical energy relative to control and monitoring circuits
with a good safety record. There is no Justification to impose
this high cost, impractical requirement on industry and
commerce. In many applications, this Panel member feels
strongly that a greater hazard would be created by s t r i c t
adherence to Section 430-113 in its present form.
430-122: Reject
CMP 11
SUBMITTER: L. A. Burton, Oconomowoc, WI
!~rO~'O-S'At-~.79
Add a new sentence as follows: The controller
~ s o
be marked with the fuse designation which will
properly coordinate the fuse with the interrupting rating of the
contractor.
• SUBSTANTIATION: Although the control manufacturer's literature
may contain sufficient information to make a proper fuse
selection, this information is not l i k e l y to be available to the
inspection authority or to an electrician when a fuse is
replaced.
I f the contacts of instantaneous relays (e.g., groundrfault
relays) are in the control circuit or i f the control voltage for
the contactor is obtained from the power systems through a
control transformer, there is an opportunity for a serious
mishap to occur under fault conditions.
The contactor will
begin to open at the inception of the fault.
I f the total clearing time of the fuse exceeds the contactor
minimum dropout time, the contactor will attempt to interrrupt
the fault current while the fuse is melting or arcing. I f the
fault current is greater than the interrupting rating of the
contactor, the fault will not be cleared by the contactor.
Ionized gases from a contactor which is f a i l i n g to interrupt may
result in other flashovers within the controller, possibly ahead
of the fuses.
The interrupting rating and opening time of contactors vary
with manufacturer and cannot be controlled by Industry
Standards. For example, a commercially available contactor has
an interrupting rating of 4400 amperes at rated voltage and an
opening time of .020 seconds. The attached* clearing
time-current curves for Motor Starter Current Limiting fuses
show that this contactor cannot be used with 9R, 12R, 18R, or
24R fuses, because fault currents in the cross-hatched area will
not be cleared by these fuses in the time i t takes for the
contactor to open. Under-these fault conditions, there is no
coordination and the contactor would be placed in the position
of attempting to interrupt a current higher than its rating.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VDTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Gubany.
EXPLANATION OF VOTE:
GUBANY: I am voting negative on Panel's rejection since I
agree with the author's substantiating comment. I t is very
timely that equipment be adequately marked for proper protection
in order for the installation to comply with Section 110-10 and
Section 240-2. The proper matching of overcurrent protective
devices with the withstand ratings of equipment and components
should'be made very obvious.
430-125(a): Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
I~TO]~[-T.'80
Delete the words "running overcurrent (overload)"
l an-6-d--~e~Face with the word "overload."
SUBSTANTIATION: See A. P. White substantiation for proposal for
Diagram 430-I.
PANEL RECOMMENDATION: Acceptas ~evised:
I Revise proposal to read - In lines 2 and 3 delete the words
"motor-running overcurrent (overload)" and replace with the word
"overload."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
"
i
430-132(d), (e), and (f)-(New): Reject
CMP 11
SUBMI1-FER: R. S. Pinkerton, Los Angeles, CA
IMTOI~S'A~-T.'81 Add new (d), (e), and (f) as follows:
--'T-d-F--Motor control equipment which is accessible to
unqualified persons shall be enclosed and shall be arranged to
be operated, including the resetting of overcurrent protective
devices, from the outside of the enclosing case.
Exception No. I: The resetting means need not be externally
operable provided the disconnecting means is part of the
controller and is so interlocked that the controller door cannot
be opened when any bare parts are energized in the controller
enclosure.
Exception No. 2: Elevator control equipment located as
204
J
providedkln Article 620 need not be enclosed.
(e) Where mechanical equipment such as valves, guages,
regulators or similar equipment which requires manual adjustment
are installed within the same enclosure with live parts,
barriers shall be provided to separate llve parts from
mechanical equipment.
(f) Where two or more contactors or other controllers are
installed in the same cabinet or other enclosure, suitable
barriers shall be installed between them.
Exception: Where all the devices in the enclosures serve a
single machine and are simultaneously de-energized by a single
disconnecting means, barriers will not be required.
SUBSTANTIATION: In the normal process of operating many types
of machines, frequent overloads require resetting of the motor
overload device or replacing fuses., Rarely is time taken to
call an electrician for this simple operation and the machine
operator resets the equipment. As people are operating this
equipment who are unqualified in terms of electrical hazards, i t
is necessary to specify and provide control equipment which is
t o t a l l y enclosed and the necessary resetting can be acc6mpllshed
without exposing the operator to energized live parts.
Furthermore, controller enclosures frequently contain
mechanical equipment which requires adjustment or contains
several controllers for independently operating machines.
Mechanics for the machines should not be exposed to live
energized parts when they turn a v~Ive or set regulator or
manually adjust mechanical equipment. Maintenance electricians
should not be required to replace motor controllers or replace
parts where there are adjacent non-barriered and energized motor
controllers.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
430-132(d), (e), and (f)-(New): Reject
CMP 11
SUBMII-I'ER: SouthwesternSection IAEI
I~-01~17TL-~.'82
(d) Motor control equipment which is accessible
~lified
persons shall be enclosed and shall be arranged
to be operated, including the resetting of overcurrent
protective devices, from the outside of the enclosing case.
Exception No. I: The resetting means need not be externally
operable provided the disconnecting means is part of the
controller and is so interlocked that the controller door cannot
be opened when any bare parts are energized in the controller
enclosure.
Exception No. 2: Elevator control equipment located as
provided in Ar{icle 620 need not be enclosed.
(e) Where mechanical equipment such as valves, gages,
regulators or similar equipment which requires manual adjustment
are installed within the same enclosure with live parts,
barriers shall be provided to separate live parts from
mechanical equipment.
(f) Where two or more contactors or other controllers are
installed in the same cabinet or other enclosure, suitable
barriers shall be installed between them.
Exception: Where all the devices in the enclosures serve a
single machine and are simultaneously de-energized by a single
disconnecting means, barriers will not be required.
SUBSTANTIATION: In the normal process of operating many types
•o f machines, frequent overloads require resetting of the motor
overload device or replacing fuses. Rarely is time taken to
call an electrician for this simple operation and the machine
operator resets th9 equipment. As people are operating this
equipment who.are unqualified in terms of electrical hazards, i t
is necessary to specify and provide control equipment which is
t o t a l l y enclosed and the necessary resetting can be accomplished
without exposing the operator to energized live parts.
Furthermore, controller enclosures frequently contain
mechanical equipment which requires adjustment or contains
several controllers for independently operating machines.
Mechanics ~or the machines should not be exposed to live
energized parts when they turn a valve or set a regulator or
manually adjust mechanical equipment. Maintenance electricians
should not be required to replace motor controllers or replace
parts where"there are adjacent non-barriered and energized motor
controllers.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is primarily a design consideration.
VOTE ON PANELRECOMMENDATION: Unanimousl~ Affirmative.
430-145(a) FPN-(New): Accept
SUBMITTER: IdahoChapter IAEI
l~TOl~)-S'At-~.'83
Add a fine print note following Section
Table 430-149: Accept
CMP 11
SUBMITTER: J. J. Kark, National Electrical Manufacturers
iITg~-6~Ta-~'fon
PROPOSAL: 84 Removethe four columns and the heading for
~ o u s
Type Unity Power Factor Amperes. Removethe +
reference at the bottom of the Table..
l SUBSTANTIATION T h i s synchronous motor portion of the two-phase
Table 430-14B should either be revised to show voltages of 230,
460 and 575 with currents for these voltages or the columns
should be eliminated.
By the time of issue of the 1981 Code, i t is the opinion of
the Submitter that there will be practically no need for this
information.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Table 430-151: Reject
CMP 11
SUBMITTER: J. J. Kark, National Electrical Manufacturers
7T~B~l'a-t-Ton
PROPOSAL: 85 Removethis Table from Article 430 and add the
of this Table as Table 440-XX in Article 440.
SUBSTANTIATION: Someconfusion has developed because the
present NEMAfable for locked-rotor.current differs some from
the values in Table 430-151. As part of Article 430, the Table
430-151 has been considered as a specification for general
purpose motors, whereas, the Table is intended for use in
conversion between current and hp ratings of other branch
circuit components. Changes in the values in Table 430-151 are
not practical because of numerous approvals of apparatus based
on these currents which are known to provide satisfactory
applications.
Correlating changes are required in Sections 430-110 and
440-12..
PANEL RECOMHENDATION: Reject.
PANEL COMMENT: See Proposal No. 85A.
VOlE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Table 430-151: Accept
CMP 11
SUBMITTER: CMP 11
85A Revise t i t l e of Table and add Fine Print Note,
Table 430-151. Conversion Table of Locked-Rotor Currents for
Selection of Disconnecting Means and Controllers as determined
from horsepower and voltage rating. For use only with Sections
450-110, 440-12 and 440-41.
Single Phase
115v
58.8
82.8
96 ,
120
144
204
336
480
600
230v
115v
200v
29.4
41.4
48
60
72
102
168
240
300
24
33.6
43.2
62
81
13.8
19.3
24.8
35.9
46.9
66
105
152
193
290
373
469
552
718
B97
1063
1325
1711
2153
2484
3312
230v
' 460v
12
16.8
21.6
31.2
40.8
58
91
132
168
252
324
408
480
624
780
924
1152
1488
1872
2160
2880
6
8.4
10.8
15.6
20.4
26.8
45.6
66
84
126
162
204
240
312
390
462
576
744
936
1080
1440
575v
Max.HP
Rating
4.8
6.6
8.4
12.6
16.2
23.4
36.6
54
66
102
132
162
192
246
312
372
462
594
750
864
1152
1/2
3/4
I
1 1/2
2
3
5
7 1/2
10
15
20
25
30
40
. 50
60
75
100
125
150
200
(FPN) *These values of motor locked-rotor current are-.
approximately 6 times the full-load current values given in
Tables 430-148 and 430-150.
SUBSTANTIATION: See Substantiation for Proposals 85 and 9g, and
to correlate with values in Tables 430-148 and 430-150.
PANEL RECOMMENDATION: Accept.
vuIE ON PANELRECOI~MENDATION: UnanimouslyAffirmative.
CMP 11
~ i o n
430-12(e)for grounding connection devices or
I f i t t i n g s required at motor terminal housings.
SUBSTANTIATION: To cross reference the grounding termination
requirements at motor terminal housings of the preceding
proposal. (See proposal 430-12(e).
PANEL RECOMMENDATION: Accept as Revised:
I Modify by changing "devices or f i t t i n g s " to "means."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Motor Locked-Rotor Current Amperes*
Two or Three Phase
• Table 430-152: Accept
CMP 11
SUBMITTER: A. P. White, Attleboro, MA
~
86
In the t i t l e , add the words, "Short-Circuit," and
~-G'~o-6-6"~ault'' after the words "Branch-circuit."
SUBSTANTIATION: See A. P. White substantiation for proposal for
ulagram 4~U-I.
PANEL RECOMMENDATION: Accept.
VUIL UN PANtL RECUMMLNDATION: UnanimouslyAffirmative.
I
205
ARTICLE 440 -- AIR-CONDITIONINGAND REFRIGERATINGEQUIPMENT
440-12(a)(2) and (b)(1)b.: Reject
CMP 11
SUBMITTER: J. J. Kark, National Electrical Manufacturers
~ o n
PROPOSAL: go Changethe references to "Table 430-151" to read
~Ta~Te-i[40-XX."
SUBSTANTIATION: See NEMAProposal - on Table 430-151.
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: See Proposal 85A.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
440-3(b): Reject
•
CMP 11
SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration
T
~
PROPOSAL: 87
Add a sentence before the iast sentence as
In no case shall the ma~ked maximumrating of the
branch-circuit short-circuit and ground-fault protective device
be less than the marked minimum supply circuit conductor
ampacity.
[
.
SUBSTANTIATION: The actual marked values may be greater than
~ m i n i m u m ,
and/or may be less than the calculated
maximum. Under the present rules, the,marked maximumrating of
the branch-circuit short-circuit and ground-fault protective
device (fuse or circuit breaker) could be less than the marked
minimum supply circuit conductor ampacity, especially since the
marked maximumfuse or circuit breaker rating is normally
redbced from the calculated maximum to a standard rating as
given in Section 240.6. The possibility of this occurrence is
greatest when a substantial part of the combination load is
electric resistance space heating. There are heat pumps on the
market with this cross-over of marked limits. Although Section
440-22(b) permits the rating of the fuse or circuit breaker to
be increased to the next standard rating higher than the
conductor ampacity (by reference to Section 430-53, which
references Section 240-3 Exception No. I ) , the marked maximum
rating of the fuse or circuit breaker cannot be exceeded. The
change is to remove unintended permission for a crossover of the
minimum and maximummarked values.
PANEL RECOMMENDATION: Reject.
~ANELCOMMENT: See Panel comment on Proposal No. 10.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Schram.
EXPLANATION OF VOTE:
SCHRAM: While we agree a design consideration is involved, i t
is the design of the marking. We do not believe the Code should
permit a marking which is in conflict with the intent, as stated
in the proposal.
440-12(b)(1), Exception: Accept
CMP 11
Secretary's Note: I t was the action of the Correlating
Committee that the Panel review the Recommendation to clarify
the use of "shall be permitted to be" and the units to be
compared.
SUBMITTER: Richard J. Denny, Air-Conditioning & Refrigeration
PROPOSAL: 91 Revise as follows:
x--~ion:
Wherepart of the concurrent load is a resistance
load and the disconnecting means is a-switch rated in horsepower
and amperes, the horsepower rating of the switch "is permitted
to" be not less than the combined load to the
motor-compressor(s) and other motor(s) at the locked-rotor
condition, "provided" the ampere rating is not less than this
locked-rotor load plus the resistance load.
SUBSTANTIATION: Change is for permissive wording. Section
440-12(b)(1) provides for adequate rating of disconnect without
application of exception. Whenmotor load is small with respect
to resistance heater load, exception may permit lower adequate
rating of disconnect; however, when motor load ~ larger with
respect to resistance heater load, application of exception
could result in higher rating of disconnect than necessary.
PANEL RECOMMENDATION: Accept as Revised:
Exception: Where part of the concurrent load is a resistance
load and the disconnecting means is a switch rated in horsepower
and amperes~the horsepower rating of the switch shall be
permitted to be not less than the combined load to the
motor-compressor(s) and other motor(s) at the locked-rotor
condition, i f the ampere rating of the switch is not less than
this locked-rotor load plus the resistance load.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
440-3(b): Reject
CMP 11
SUBMITTER: Alton R. Thompson, Durham, NC
I~rOIR~-~.~ Add a sentence before the last sentence as
440-14: Accept
CMP 11
Secretary's Note: I t was the action of the Correlating
Cor~nittee that the Panel review the Recommendation with respect
to the fine print note.
SUBMITTER: L~uis Miraglia, Boston, MA
~-R-O-F~'A-L-~.'92 Delete the word "readily."
~]~r~'~I~I'IATION: In my opinion refrigerators have had outlets
behind them for years. I have yet to hear of any person who has
been injured from such an installation:
Household refrigerators should be considered as an applicance
occupying dedicated space as per 210-25(b) (second paragraph).
PANEL RECOMMENDATION: Accept asRevised:
Change Section 440-14 to read:
Location. A disconnecting means shall be located within sight
from and readily accessible from the air-conditioning or
refrigerating equipment. Add an exception reading:
Exception: Cord- and plug-connected appliances.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
SCHRAM: The only change in Section 440-14 is to add the
exception. The present fine print note should be retained.
In no case shall the marked maximumrating of the
branch-circuit, short-circuit and ground-fault protective device
be less than the marked minimum supply circuit conductor
amapcity.
SUBSTANTIATION: The actual marked values may be greater than
the calculated minimum, and/or may be less than the calculated
maximum. Under the present rules, the marked maximumrating of
the branch-clrcuit, short-circuit and ground-fault protective
device (fuse or circuit breaker), could be less than the marked
minimum supply circuit conductor ampacity, especially since the
marked maximumfuse or circuit breaker rating is normally
reduced from the calculated maximum to a standard rating as
given in Section 240-6. The possibility of this occurrence is
greatest when a substantial part of the combination load is
electric resistance space heating. There are heat pumps on the
market with this cross-over of marked limits. Although" Section
440-220(b) permits the rating of the fuse or circuit breaker to
be increased to the next standard rating higher than the
conductor ampacity (by reference to Section 430-53, which
references Section 240-3 Exception No. I ) , the marked maximum
rating of the fuse or circuit breaker cannot be exceeded. The
change is to remove unintended permission for a cress-over of
the minimum and maximummarked values.
PANEL RECOMMENDATION: Reject.
I
PANEL COMMENT: See Panel comment on Proposal No. 10.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Schram.
EXPLANATION OF VOTE:
SCHRAM: See Comment on Proposal No. 88.
440-21: Accept
.CMP 11
SUBMITTER: A. P. White, Attl~boro, MA
l~TO!~O~'Al~.'g3" Delete the word "overcurrent" in line one.
~'I~']7~rIATION: See A. P. White substantiation for proposal for
Diagram 430-I.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative:
•
440-3(c) FPN: Reject
CMP 11
SUBMITTER: W. L. Howard, General Electric Co.
P]TOI~T~L-~." 89 Revise the last sentence of fine print note as
The value of the branch-circuit selection current will
never be less than the rated load current.
SUBSTANTIATION: Present wording would have the effect of
arbitrarily adding some value of current to a rated load current
which is already greater than or equal to 64.1% of the maximum
continuous current of the compressor.
PANEL RECOI~ENDATION: Reject.
PANEL COMMENT: The present wording adequately ~eflects the
Panel's intent.
VOTE ON PANELRECO~@IENDATION: UnanimouslyAffirmative.
440-22(b) Exception No. 3-(New~(HOD 1978 NEC): Accept
CMP 11
Secretary's Note: I t was the action of the Correlating
Committee that this Proposal be reported as a "reject," because
less than two-thirds of the members eligible to vote havenot voted
in the affirmative.
SUBMITTER: J. A. Pietsch, General Electric Company
~ 9 4
Add Exception No. 3 to Section 440-22(b) as
TBT~.
Exception No. 3: Where the branch circuit, short-circuit and
ground-fault protection is rated 60 amps or less and 250 volts
or less, either fuses or inverse-time type circuit breakers may
be installed unless otherwise .li@ited by marking on the
equipment nameplate.
SUBSTANTIATION: The intent of this proposal and a related
proposal to change Section 424-22(a) is to permit the use of
inverse time t~q~e circuit breakers where appropriate on fixed
Heating, Air Conditioning and Refrlgeration Equipment branch
circuits.
206
installation, or possibly group installations should even be
prohibited.
LOPEZ: I am abstaining from voting on this proposal and
deferring this to the judgment of other Panel members who have
the specialized know how and experience relative to the
application and protection of the equipment covered by this
proposal.
MYERS: Circuit breaker test data submitted at the Panel
meeting was impressive but i t was a test of only one
manufacturers circuit breaker. I f this proposal is approved i t
would give blanket approval to all circuit breakers. I feel
this is a problem that must be resolved between the
manufacturers and a recognized testing agency, not the
CodeLMaking Panel.
O'BRIEN: Our position is to reject Proposal No. 94 due to
insufficient evidence to support the suggested changes. I t is
our position that the consumer is better protected w i t h t h e
present language in the Code.
OSBORN: Data submitted puts serious doubts on the
advisability of multi-motor branch circuit with any type of
overcurrent protection. CMP 11 now should restudy multi-motor
branch circuit protection.
SMITH: The present wording of the proposal automatically
qualifies inverse-time type circuit breakers for the purpose.
The NEC should not be the judge of a products a b i l i t y to perform
adequately or safely. The agency to perform the above should be
a recognized testing laboratory.
I f the capability of the circuit breaker to protect is
demonstrated and documented then this proposal is acceptable.
Successful results with specific equipments approved as
individual types or models for circuit breaker branch circuit
protection have shown that such devices do not constitute a
safety hazard. And, the circuit breakers permit improved
protection to power u t i l i z a t i o n equipment by disconnecting all
ungrounded supply conductors simultaneously.
PANEL RECOMMENDATION: Accept as Revised.
Change 60 amps. to 50 amps.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 7.
NEGATIVE: Ananian, Gubany, Kish, Lawry, Myers, O'Brien,
Osborn, Smith.
NOT VOTING: Aquilino, Lopez.
COP~MENTON VOTE:
SCHRAM: We believe the data submitted supports acceptance of
the proposal without the reduction to 50 amperes.
WOOD: I have voted in the affirmative on this proposal since
i t is generally known that a large percentage of these
installations have been installed with circuit breaker
protection.
There appears to be very l i t t l e evidence of this type
installation causing or contributing to loss of l i f e or f i r e .
Through the various test data supplied to the Panel i t has
become apparent to me that no overload devices, fuses or circuit
breakers, provide adequate protection on multi-motor circuits.
This Panel should review its position regarding protection on
all types of multi-motor circuits as i t appears that damage to
circuit components is prevalent when any single overload device
is used.
EXPLANATION OF VOTE:
ANANIAN: In reviewing the Fact-Finding Report conducted by UL
for the Air Conditioning and Refrigeration Institute and
subsequent tests conducted by fuse and circuit breaker
manufacturers, i t appears that inadvertent use of either 60
ampere fuses or circuit breakers may result in equipment
component and/or wire damageand burning. One would have to
conclude that the equipment branch-circuit/short-circuit and
ground fault protective devices used in these tests, whether
fuse or circuit breaker, cannot assure the protection of No. 18
nor No. 16 tap conductor wires nor certain components. Small
wire sizes, overload heaters and contactors have limited thermal
~tc~;~Yan~h~r~l~i~t~tec~X~e~,W~a~h
440-22(b), Exception No. 3-(New): Reject
• CMP 11
SUBMITTER: J.J. Kark, National Electrical Manufacturers Assn.
Pl~-OlTO-S'XL-~.95
Add Exception No. 3 as follows:
~"xc-eption No. 3: Where the branch-circuit, short-circuit and
ground-fault protection is rated 60 amps or less and 250 volts
or less, and where the available f a u l t current is 5000 amps or
less, either fuses or inverse-time type c i r c u i t breakers may be
installed unless otherwise limited by marking on the equipment
nameplate.
SUBSTANTIATION: The intent of this proposal and a related
proposal to cnange 424-22(a) is to permit the use of
inverse-time type circuit breakers where appropriate on fixed
heating, air conditioning and refrigeration equipment branch
circuits.
A UL Fact-Finding Report dated Nov. 1, 1976 was conducted to
investigate the s u i t a b i l i t y of inverse-tlme circuit breakers for
these applications.
Unfortunately~ close timing between issuance of the Report and
the final vote by the panel l e f t l i t t l e time for thorough study
for the 1978 Code.
A careful review indicates that circuit breakers were t o t a l l y
acceptable in 97% of the 387 tests summarized in the report.
The remalning tests had minor discrepancies.
A f i e l d survey included in the report indicates that over 50%
of the defined units installed since 1971 are in fact protected
by circuit breakers with no f i e l d problems.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See action on Proposal No. 94.
,VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
are
conditioning equipment incorporating multi-motor loads or motors
mixed with other loads and u t i l i z i n g reduced wire size tap
conductors in compliance with 430-53(d) would appear to need to
be tested as an integrated and coordinated system u t i l i z i n g
"specific branch circuit protective devices. The circuit
components and associated wiring would need to be tested at both
low and high level fault currents to verify 12T withstand and
thermal ratings approved for the installation by a recognized
testing laboratory.
AQUILINO: Considerable test data has been presented both for
and against this proposal. In view of the conflicting data, and
lacking the f a c i l i t i e s to confirm the test results myself, I do
not feel there is sufficient j u s t i f i c a t i o n for either an
affirmative or negative vote at this ~ime.
GUBANY: I am voting against acceptance of Proposal No. 94 for
the following reasons:
I . This is the same type of proposal which was declared
nonconsensus for the 1978 Code.
2. No new substantiating data was submitted at the last
OMP 11 meeting to refute the ARI/UL Fact-Finding Report which
recorded destroyed and damaged air-conditioning and electric
furnace components. Section 110-10 requires component
protection and 240-2 requires protection of equipment, not "
destruction.
3. Using 50A, 60A and even IOOA overcurrent devices to
protect No. 18 and No. 16 wire is out of concert with other
sections of the NEC as well as the intent of the NEC which
limits the protection to 20A as in 240-4, such as in fixtures
and approved cords for appliances which generally do not exceed
six (6),feet. Even in 725-12, where the conductors leave the
enclosure, the overcurrent protection is limited to 20A.
K
.
4. The change from 60A to 50A branch clrcult doesn't change
the damage and destruction recorded in the ARI/UL Fact-Finding
Report of 1978 and no new Fact-Finding Report was submitted on
component protection. An air-conditioner or any other equipment
can have any size branch circuit.
5. The owners" or users' equipment or property should not be
permitted to be subjected to the damage and destruction reported
in the 1978 ARI/UL Fact-Finding Report using circuit breakers.
NOTE I : Section 240-2 refers to Protection of Equipment, not
destruction. Also, note 240-1, the word "protection" is
prominent.
NOTE 2: This Proposal is for all practical purposes the same
as Proposal No. 57 which the Panel voted to reject.
KISH: Approval for either fused or inverse-time type circuit
breakers should not get a blanket approval. While tests were
run on specific fuses and circuit breakers to show their
worthiness, approval should come only from recognized testing
laboratories for each grouping.
LAWRY: I t has been suggested that test data submitted to CMP
11 indicates that circuit breakers are as safe as fuses for
group motor installations and consequently, as for fuses, should
be recognized for group installations without specific approval
for that purpose. In my opinion, the test data indicates that
both fuses and circuit breakers should be approved for group
440-52(b), Exception: Reject
CMP 11
SUBMITTER: R. L. Eichhorn, Whirlpool Corp.
~ 9 6
Revise exception by adding:
~ o n
20-, 30-, 40-, or 50-ampere single-phase branch
circuits as provided in Section 440-56."
SUBSTANTIATION: This is a correlating proposal to the proposal
to add Section 440-56 Cord-and-Attachment Plug-Connected
Motor-Compressors and Equipment on 20-, 30-, 40-, or 50-Ampere
Branch Circuits.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
440-55 and (b): Reject
CMP 11
SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration
T ~
PROPOSAL: 97 Revise as follows:
7F4-O-z-5=~F~
- . Cord-and-Attachment Plug Connected Motor-Compressors
and Equipment on 15-, 20-, 30-, 40- or 50-Ampere Branch
Circuits. Overload protection for motor-compressors and
equipment that are cord- and attachment plug-connected and used
on 15-or 20-ampere 120-volt, or 15-, 20-, 30-, 40- or 50-ampere
208-or 240-volt, single-phase, branch circuits as permitted in
A~ticle 210 shall be permitted as indicated in (a), (b) and (c)
below.
(b) The rating of the attachment plug and receptacle shall
not exceed 20 amperes at 125 volts or 50 amperes at 250 volts.
SUBSTANTIATION: Equipment for circuits larger than 20 amperes
require additional testing to meet the present code requirements.
440-22(b), Exception No. 2 provides for such equipment to be
considered as a single motor.
Section 210-21(b)(I) and Tables 210-21(b)(2) and 210-21(b)(3)
207
allow for individual branch circuits and matching plug
receptacles up to 50 amperes.
Further, Section 210-23 states " I t shall be acceptable for an
individual branch circuit to supply any load for which i t is
rated."
The overload protection need only protect the equipment per
440-52(a). The protection of the branch circuit and control
apparatus required under 440-52(b) is not needed since i t is
,provided by the branch circuit protection.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
Change line I f i r s t paragraph word: "Running" to "Overload."
Change lines 2 and 3 f i r s t paragraph words: "running
overcurrent" to "overload."
Change lines I and 2 second paragraph words: "overcurrent" to
"short-circuit and ground-fault."
Change lines i and 3 third paragraph words: "overcurrent" to
"short-circuit and ground-fault."
Change line 1 fourth paragraph word: "overcurrent" to
"short-circuit and ground fault."
SUBSTANTIATION: See A. P. White substantiation for proposal for
Diagram 430-1.
PANEL RECOMMENDATION: Accept as Revised.
In Chapter 9, Example 8 change the following'to read:
Change the heading "Overcurrent Protection" to "O~erload and
Short-Circuit and Ground-Fault Protection.
Change subheading "Running" to "Overload."
Add to paragraph 1, before "the 25-h.p. motor," "Where
protected by a separate overload device."
In the 1st sentence add after "42.5 amperes.", "(Section
430-32(a)(i))."
In the second sentence before "the 30-h.p. motor," add "Where
protected by a separate overload device." Also in the second
sentence add after "not over'50 amperes.", ,"(Section
430-32(a)(i))."
At the end of paragraph I , add a new sentence to read: For a
motor marked "thermally protected" overload protection is
provided by the thermal protector (see Sections 430-7(a)(12) and
430-32(a)(2)). Change second subheading "Branch Circuit" to
read "Branch Circuit, Short-Circuit and Ground-Fault."
In subheading "Feeder Circuit" add to the end of paragraph
"(Section 430-62(a)). ~
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
COMMENT ON VOTE:
SCHRAM: The Panel Recommendation should be to add the changes
identified to thechanges proposed.
WHITE: The Panel Recommendation revision should be in
addition to the original proposal and not as a replacement.
Otherwise, the revision contemplated in Proposal No. 100 would
be incomplete.
440-56-(New): Reject
CMP 11
SUBMITTER: R. L. Eichhorn, Whirlpool Corp.
98 Add a new sentence as follows:
2RFO-z~T~--. Cord-and Attachment Plug-Connected Motor-Compressors
and Equipment on 20-, 30-, 40-, 50-Ampere Branch Circuits.
Overload protection for motor-compressors and equipment that are
cord-and attachment plug-connected, approved for the purpose,
and used on 20-, 30-, 40-, or 50-amphere 208- or 24D-volt,
single-phase branch circuits as permitted in Article 210 shall
be permitted as indicated in (a), (b), and (c) below.
(a) The motor compressor shall be provided with overload
protection as specified in Section'44O-52(a). Both the
controller and motor overload protective device shall be
approved for installation with the short-circuit and
ground-fault protective.device for the branch circuit to which
the equipment is connected.
(b) The rating of the attachment plug and receptacle shall
not exceed 50 amperes at 250 volts.
(c) The short-circuit and ground-fault protective device
protecting the branch circuit shall have sufficient time delay
to permit the motor-compressor and other motors to start and
accelerate their loads.
SUBSTANTIATION: Cord-and attachment-plug connected equipment
for circuits 20 amperes and larger may require additional
testing to meet the existing code requirements. This additional
testin~ is considered unnecessary since field experience with
well over a million room air conditioners rated over 15 amperes
to 40 amperes and not tested in accordance with the existing
code have not ~hown any safety problems due to this lack of
testing. Results of an AHAMsurvey of manufacturers disclosed
this information.
Section 440-22(b), Exception No. 2 provides for such equipment
to be considered a single motor for the purpose of specifying
branch-circuit short-circuit and ground-fault protection.
Section 210-21(b) (I) permits a single receptacle installed on
an individual branch circuit up to the rating of the branch
circuit and up to 50 amperes.
See correlating proposal for revision of section 440-52(b)
Exception.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
Table 440-XX-(New): 'Reject
CMP 11
SUBMITTER: J. JL Kark, National Electrical Manufacturers
~ o n
PROPOSAL: 99 Use the complete contents of Table 430-151 from
Code with the following t i t l e :
TABLE 440-XX. Conversion Table of Locked-Rotor
Currents for Selection of Disconnecting Means
and Controllers
As determined from horsepower and voltage rating. For use
only with Sections 430-110, 440-12 and 440-41.
SUBSTANTIATION: The addition of the purpose of the Table to the
bold face heading should eliminate any confusion about the use
of the Table in application of the Code. Also, see the comment
on the NEMA
proposal - on Table 430-151.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Proposal No. 85A.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
CHAPTER 9 -- TABLES AND EXAMPLES
Chapter 9, Example No. 8: Accept
CMP 11
Secretary's Note: I t was the action of the Correlating
Committee that the responsibility for the Examples has been
assigned to the Chairman of the Panel and the Secretary of the
Correlating Committee.
SUBMITTER: A. P. White, Attleboro, MA
Lb-R~-POSAL: 100 Change in t i t l e word: "Overcurrent" to overload
~t-Circuit
and Ground-Fault."
Change in line I f i r s t paragraph words: "running overcurrent"
to "overload."
Insert in l~ne 2 f i r s t paragraph words: "short-circuit and
ground-fault ahead of "protection."
Change heading "Overcurrent Protection" to "Overload and
Short-Circuit and Ground-Fault Protection."
Under heading Overeurrent Protection-
208
REPORT OF CODE-MAKINGPANEL NO. 22
ARTICLE445 -- GENERATORS
445-I: Reject
CMP 22
SUBMITTER: IdahoChapter IAEI
]5~-Ob
l -O-SA
' ~-~." 1
AmendSection 445-1 to include Article 240.
~]I~rANTIATION: 240-21 t e l l s us all conductors shall be
protected at point of supply. The inherent design of a
enerator only protects the generator i t s e l f . Nowherein
r t i c l e 445 does i t give any specific overcurrent protection for
the conduEtor leading from the generator.
These generators can be changed in the field to a larger
generator without any knowledge of conductor ~npacity or
overcurrent requirements thereby causing an overload on the
conductors and creating a f i r e hazard. In some installations
the conductors leading from the generator to the f i r s t
overcurrent device is greater than 100 feet.
See Proposal No. 3 for 445-5.
"PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Unduly restricting design for larger units where
other methods to prevent overloading of conductors have shown to
be adequate. Supporting comment is not persuasive. This
article outlines requirements for protection of generators.
Other sections of the NEC cover conductor overcurrent
protection. Modifications of systems must be reviewed
completely for compliance with all rules applicable in the NEC.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: g.
NEGATIVE: Flach.
EXPLANATION OF VOTE:
FLACM: I don't think adding Article 240 to the l i s t of other
Articles will create any controversy. By doing this, Code users
will be alerted to the fact that the inherent design of a
generator does not protect conductors connected to the generator
output terminals.
~
be adequate. Overcurrent protectioh should be as close as
practicle, but 25 feet is too restrictive.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Flach, Scalone.
EXPLANATION OF VOTE:
FLACH: I agree that 25 feet may be too short for large
machines, but there should be some statement in the Article
which requires overcurrent protection for the conductors
connected to the generator.
SCALONE: The installation of an unprotected feeder for great
distances within a building might cause a greater threat to
human l i f e such as f i r e , explosion or electrocution, than would
be caused by the lack of emergency power. I suggest modifying
the proposed wording:
"The length of exposed feeder installed from the generator
terminals to the f i r s t overcurrent protective device shall not
exceed 25 feet."
445-6: Accept
CMP 22
SUBMITTER: TSC-Nominal Voltage
I~TOIR)~L-~.4 Change"generators of more than 150 volts to
grou-~-u-6~--to read "generators operated at more than 150 volts t o
iground.,
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 480
STORAGEBATTERIES
480-5(b):Accept
CMP 22
SUBMITTER: TSC-Nominal Voltage
I~ROIoI)~3~-~.
• 5
Add "nominal" after "24 volts" to read "(24
vo-'61"t-~7-5,
nominal)."
SUBSTANTIATION: To conform to the guidelines established by the i
TSC on Nominal Voltages.
PANEL RECOI~MENDATION: Accept
VOTE ON PANELRECOMMENDATION: Unanimously AffirmatiVe.
445-5: Reject
CMP 22
SUBMITTER: GeorgeW. Flach, New Orleans, LA
2
Reviseby adding "and neutral" after "phase
~ r s . "
The sentence will then read: "The ampacity of the
phase conductors and neutral from the generator terminals to the
f i r s t overcurrent device shall not be less than 115 percent of
the nameplate current:rating of the generator.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal see
actlon on Proposal No. 2A, Section 445-5.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 700 -- EMERGENCYSYSTEMS
Article 700: Reject
CMP 22
SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn.
]~-OPO~'-A-L-~.'6 CemblneArticles 700 and 750.
~'I]I)'S'TA)~TIATION: Adopt the report of CMP TSC to combine Articles
700 and 750r Complete text as shown on pages 391, 392, 393, 394
of the "Preprint of the proposed amendments for the 1978
National Electrical Code." NFPANO. 70 PR 78.
The present separation of the articles, both of which deal
with alternate power sources and distribution systems intended
to be functional when normal power supplies are disrupted, is
illogical and is a source of conflict in application and
enforcement.
The TSC report was well conceived and the integrated subject
matter provides a much more coherent coverage of alternate Power
Systems. The supporting comment by CMP 22 which accompanied the
proposal thoroughly covers the subject and is s t i l l pertinent.
The Correlating Co¢mnittee (see Secretary's note) apparently
agreed with the developed material, but unfortunately the
assignment to "process new material in the appropriate articles"
was not accemplished. Such action to pull apart the work of the
TSC would be ill-advised and would destroy the logical
arrangement.
PANEL RECOMMENDATION: Reject
PANEL COMMENT: See CMP action on Proposal No. 7. The
Correlatlng ~emmittee has instructed CMP 22 to keep the articles
separate.
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
COW,lENT ON VOFE:
FLACH: Separating this proposal as has been done in Proposal
NOS. 21A through 21S should reduce this confusion between
requirements for emergency, legally required stand-by, and
optional stand-by systems.
445-5: Accept
CMP 22
SUBMITTER: CMP 22
I~TOITO-S)'~-~
". 2A
Add a sentence to the end of 445-5 as follows:
be permitted t o size the neutral conductors in
accordance with Section 220-22.
SUBSTANTIATION: To clarify requirements for sizing the neutral.
To be consistent in sizing the neutral with other sources and
distribution methods.
PANEL RECOMMENDATION: Accept as revised. I t shall be permitted
to slze the neutral conductors in accordance with Section
220-22. Conductors which must carry ground-fault currents shall
not be smaller than required by Section 250-23(b).
PANEL COII~ENT: Where the generator neutral is not grounded at
Its terminal, the neutral cohductor must be of adequate size to
carry ground-fault current.
VOTE ON PANELRECO~B~ENDATION: UnanimouslyAffirmative.
445-5: Reject
CMP 22
SUBMITTER: IdahoChapter IAEI
3
Amend445-5 by adding another sentence stating
~ductor
shall not be over 25 feet in length and shall
terminate with a single circuit breaker or a single set of fuses
that will limit the load to the ampacity of the conductors."
SUBSTANTIATION: 250-5(d) states that generators are a
separately derived system. I f they are such we should have some
rules for giving the conductors from the generator proper
protection. There are times when i t is hard to install an
overcurrent device at the generator location. I f we used a 25
foot tap rule from the generator to the overcurrent device i t
would prevent installations of great distance from the generator
to the overcurrent device.
240-21 tells us all conductors shall be protected at point of
supply. The inherent design of a generator only protects the
generator i t s e l f . Nowherein Article 445 does i t give any
specific overcurrent protection for the conductor leading from
the generator.
See Proposal No. 1 for 445-I.
PANEL RECOMMENDATION: Reject
PANEL COMMENT: Unduly restricting design for larger units where,
other methods to prevent overloading of conductors have shown to
- -
Article 700 and 750-(New)(HOD 1978 NEC): Reject
CMP 22
SUBMITTER: CMP 22
RTOIO~3XLr•~. 7
Reportof CMP TSC to combine Articles 700 and 750
ARTICLE 700
ALTERNATE POWERSYSTEMS
A. General
' 700-1. Scope. The provisions of this article apply to the
installation, operation, and maintenance of systems consisting
of circuits and equipment intended to distribute and control
electricity for illumination and/or power when the normal supply
or system is interrupted. Unless specifically referenced, these
provisions do not apply to health care f a c i l i t i e s which are
covered by Article 517.
j
700-2. An alternate power system shall be classified as one of
the following:
332
-
REPORT OF CODE-MAKINGPANEL NO. 13
450-3: Reject
CMP 13
SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn.
]~TOPO-S'~I[-T 4
Add a new sentence as follows:
~ondary
side of a transformer shall be permitted to be
protected by one or more secondary overcurrent devices where
secondary taps are not over 10 feet long and the total capacity
of the protective devlce(st does not exceed 125 percent of the
transformer rating.
SUBSTANTIATION: There are problems in this area in the
interpretation of this section as to when secondary overcurrent
protection is required when secondary taps are involved. We
believe this proposal will correct the problem, and Is
consistent with Sections 240-3 and 240-21.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Already~overed by Section 240-21.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 450 -- TRNASFORMERSAND TRANSFORMERVAULTS
450-1, Exception No. g-(New): Reject
CMP 13
SUBMITTER: J. D. Riley, Industrial Gas Cleaning Institute
1
ExceptionNo. g: Transformer used as controlled
power supplles for electrostatic precipitators.
SUBSTANTIATION: To exempt electrostatic preciptator power
supplies from any require~nts for protection from explosion,
f i r e and/or tank rupture such as9 Vaults, pressure r e l i e f
vents, space separation, barriers, water spray systems,
enclosures, dikes, basin or trapped drains.
Such requirements are being enforced by so~ interpreters of
NEC Articles 450-23, 450-24, 450-25 and 450-26.
Industrial Electrostatic Precipitator Power Supplies are not
used as transformers in the normal sense, but rather as sources
of hlgh voltage (35,000-75,000 volts) and low current (less than
3 amps) power for operation of electrostatic precipitators. In
such use they are connected to a sophisticated, automatic
primary control system complete with overload protection,
secondary current sensing and spark sensing and limiting
circuitry which effectively prevents the occurrence of
conditions which would cause explosions within thetank.
Operating experience since the early 1goD's in thousands of
applications has yielded no known occurrences of explosions of
electrostatic precipitator power supplies.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Total exem1~tion from all requirements of Article
450 is not justified in view of the possible significant amount
of combustibles involved.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
450-3(a): Accept
CMP 13
SUBMITTER: TSC-Nomlnal Voltage
•
5
Add "neminal" after "600 volts" in (at, ( a t ( I t ,
an---~2 )
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECO~IENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimogslyA f f i r m a t i v e .
l
450-3(a) and Table 450-3(a)(2): Accept'
CMP 13
SUBMITFER: F. L. Cameron, NEMASG-2 High Voltage Fuse Technical
~PROPOSAL: 6
450-3(a)(1) - Change 150 percent to 250 percent.
~ n
No. I to above - Change 150 percent to 250 percent.
Table 450-3(a)(2): Under the column: Primary, Over 600
Volts, Fuse Rating - Change 200 percent to 300 percent. Under
the column: Secondary, Over 600 Volts, Fuse Rating - Change 150
)ercent to 250 percent and change 125 percent to 225 percent.
SUBSTANTIATION: Prior to 1975, the allowable fuse sizing was
permitted to be as large as 250 percent of the rated primary
current of the transformer. Becauseof some reputed troubles
with transformers rated 600 volts or less, the value was reduced
to 125 percent. There had been no reported cases of
d i f f i c u l t i e s with high voltage equipments utilizing the 250
percent value. The institution of low ratio values for high
voltage transformers does, i t s e l f , lead to problems when the
primary protection consists of high voltage fuses. \
Example: 1. The inherent overload capacity of the
transformer cannot be utilized when the ratio of fuse rating to
transformer rating is low. Transformers are large devices with
a significant thermal capacity. Fuses are small in mass and
cannot handle the same degree of overloading. This severely,
and unnecessarily, limits the user.
Example: 2. A low ratio of fuse to transformer rating
sometimes leads to melting of the fuses on inrush when the
transformers are energized. Sometransformers today allow
inrush currents of 35-40 times the f u l l load rating current.
High voltage fuses confronted with this type of melting will
react, at best, by nuisance tripping and may even f a i l to
adequately clear the hlgh voltage circuit i f the i n i t i a l energy
is inadequate to f u l l y burn-back the fuse element(s).
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-2 (New): Accept
CMP 13
Secretary's Note: I t was the action of the Correlating
Committee that further consideration be given to the comments
expressed in the voting and that the Panel put the references to
the various standards into fine print notes rather than a
mandatory requirement.
SUBMITTER: CMP 13
PROPOSAL: 33 (CMP I) Add a new paragraph after Exception No. 2
as-~-T611-ows:
As used in the Article the term f i r e resistant means a
construction having a minimum f i r e rating of one hour, unless
specified otherwise according to ASTMStandard E 119-75; Fire
Tests of Building Construction and materials, NFPA251-1972;
also Methods of Fire Tests of Building Construction and
Materials ANSI A2.1-1972.
SUBSTANTIATION: C~ 1 referred Proposa.l No. 33 for a new
definition for "Fire-resistant construction" to CMP 13 for
action..
PANEL RECOMMENDATION: Accept
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COF~MENTON VOTE:
O'NEILL: The wording of the new paragraph needs to be
revised. The phrase "unless specified otherwise" is improperly
located., A suggested wording may be: "As used in the Article
the term f i r e resistant means a construction having a minimum "
f i r e rating of one hour according to ASTM. . . . and Materials, ANSI
A2.1-1972, unless otherwise specified in the text.
i
•
450-2, Exception Nos. 1 and 2: Accept
CMP 13
SUBMITTER: TSC-Nominal V~ltage
~
2
In Exception Nos. I and 2 add "nominal" after
~'6"O0"-~[ts. ,
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code.,
PANEL RECOMMENDATION: Accept.
yOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
450-3(b): Accept
C~ 13
SUBMITTER: TSC-Nominal Voltage
7
Add "nominal" af t er "600 volts" in (b), (b)(1),
an-~d-TB)T2).
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code,
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-3: Reject
CMP 13
SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn.
3
Add a new sentence as follows:
~ormer
secondary conductors (other than 2 wire) are not
considered to be protected by the primary overcurrent protection.
SUBSTANTIATION: There are problems in this area in the
interpretation of this section as to when secondary overcurrent
protection is required. We believe this addition will correct
the problem, also i t is consistent with the Exception No. 5 of
Section 240-3.
PANEL RECOMMENDATION: Reject.
•PANEL COMMENT: "Already covered by Section 240-3.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
450-3(b)(I), Exception No. 1: Reject
CMP 13
SUBMITTER: Idaho Chapter IAEI
8
Delete f i r s t sentence and rewrite to read: Where
rated primary of a transformer is 9 amperes or more, an
overcurrent device rated or set at not more than 125 percent of
this current rating shall be.permitted. (The rest of the
Section to remain unchanged.)
SUBSTANTIATION: Permitting the primary overcurrent protection
of a transformer to be increased 125 percent above its primary
rating does not seem to be out of line but'when considering the
supporting comment for Proposal No. 7, Page 178 in the Preprint
for the 1975 Code, i t does, however, lose us in a lot of
mathematical figures, as you will note from the following exerpt:
Due to the required derating of overcurrent devices f u l l use
of transformer design capacity is not now possible. As an
example, a 30kVA, 3-phase, 208-volt transformer has, a full-load
secondary current of 83.33 amps; 125 percent of this value is
104.16. I f a fused switch were used for secondary protection,
the largest size standard fuse that could be used and not exceed
the 104.16 amps is IOD amps. However, UL Standard 98, Section
I
211
214 and NEMAStandard KS 1-1969 Section 2.80(b) states:
"A fused switch shall be marked as a part of the electrical
rating: Continuous Load Current not to exceed 80 percent of the
Rating of Fuses Employed in other than Motor Circuits."
Therefore, the maximum load that could be supplied is 80 amps
or 96 percent of the transformer design capacity.
The proposal would allow 100 percent use of transformer design
capacity and be consistent with similar provisions for motors
(Section 430-52) and conductors (Section 240-5, Exception No. 1).
The comment draws a lot of sympathy in that the 80 percent
continuous duty factor permitted only 96 percent use of the
transformer design but failed to mention the fact that by going,
to the nex't larger size its rating with continuous loading
permitted to 120 percent. Take the case of dry transformers
which are designed with a high heat rise with all this high
temperature wire insulation that is available. With all this
design focused on a 100 percent operation factor is does not
seem logical to push this heat rise another 20 percent providing
the overcurrent device is loaded properly to 80 p~rcent
(continuous load). Overcurrent protection is an item the Code
relies on as, a safety factor when something out of the ordinary
develops or is faulted into a circuit. I t seems that we have
not only lost a partial but a great deal of the safety when this
protection can be increased to 150 percent of the rating of a
transformer when i t is for the purpose of recovering only 4
percent of the transformer design.
The last paragraph of the 1974 Preprint supporting comments
included herein is not only in error, i t serves as the piece o f
wool over the eyes because i t actually permits from 120 to 150
percent loading of the transformer instead of the 100 percent
heralded in the comments. Actual in the field experience is
that the overcurrent device is taken at face value (rating) and
in many cases the transformers are operating at over a 100
percent with the permitted 125 percent factor.
Just because the 125 percent mistake has been made in the past
and has warped all face values out of proportion to where
ampacity ratings are becoming a farce, are we committed to
continue to do so especially when transformers of 112 1/2 KVA
rating and less are not required in a f i r e resistant room?
PANEL RECOI~MENDATION: Reject.
PANEL COMaMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOP~4ENDATION: UnanimouslyAffirmative.
450-5: Accept
CMP 13
SUBMITTER: TSC-Nominal Voltage
I PROPOSAL: 9
In the f i r s t line add "nominal" after "600 volts."
'~IATION:
.To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECO~MENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-8: Accept
CMP 13
SUBMI1-TER: O. E. Dillon, Border County Div. IAEI
!~ITO]~-O-S-AI--~
•. 10 Revise as follows:
450-8. Ventilation. The ventilation shall be adequate to
dispose of the transformer full-load losses without creating
temperature rise which is in excess of the transformer rating.
SUBSTANTIATION: The use of the word "excessive" renders this
section legally unenforceable. See the attached ppinion* of the
San Diego City Attorney.
• See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Accept as Revised:
Fine Print Note to remain.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-21: Reject
P
CMP 13
SUBMI1-TER: TSC-Nominal Voltage
~
12 In the last paragraph add "nominal" after "35,000
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECO~MENDATION: UnanimouslyAffirmative.
I
450-22: Accept
CMP 13
SUBMITTER: R. S. Pinkerton, Los Angeles, CA
I~TOI}-O~'AL-:-.'13 Add a paragraph as follows:
~ormers
exceeding 112 1/2 kVA shall not be located within
12 inches of combustible materials, buildings, f i r e escapes,
roofs, or door or window openings unless separated therefrom as
specified by Section 450-21.
SUBSTANTIAT~QN: A transfQr:mer,which has a seriOUS internal.
~ca~I
UTTer the sameTire nazaro to adjacent combustible
~aterials when installed outdoors as i t does when installed
~ndoors. Therefore, the spacing or separation from combustible
materials should be the same.
PANEL RECOMMENDATION: Accept as Revised:
I "Transformers exceeding 112 1/2 kVA shall not be located
within 12 inches of combustible materials of buildings."
PANEL COI~MENT: Panel agrees with intent of Proposal, but feels
its scope was too broad as submitted.
VOTE ON PANELRECO~ENDATION:
AFFIRMATIVE: 12.
NEGATIVE: Boyd.
EXPLANATION OF VOTE:
,
i
BOYD: Support proposal as submitted. Prescribed clearance to
window and door openings reasonable.
450-22: Reject
CMP 13
SUBMII-fER: SouthwesternSection IAEI
14 Add the following to Section 450-22:
--'T-~a-ns-irormers exceeding 112 I/2 kVA shall not be located within
12 inches of combustible materials, buildings, f i r e escapes
roofs or door or window openings unless separated therefrom as
specified by Section 450-21.
SUBSTANTIATION: A transformer which has a serious internal
fault can offer the same f i r e hazard to adjacent combustible
materials when installed outdoors as i t does when installed
indoors. Therefore, the spacing or separation from combustible
materials should be the same.
PANEL RECO~MENDATION: Reject.
PANEL COI~MENT: This Proposal is identical to Proposal No, 13.
See Panel's action on Proposal'No. 13.
VOTE ON PANELRECOI~MENDATION:
AFFIRMATIVE: 12.
NEGATIVE: Boyd.
EXPLANATION OF VOTE:
BOYD: Samecomment as In Proposal No. 13.
450-23: Reject
CMP 13
SUBMITTER: JeromeM. Frank, Square D Co.
15 In the second sentence of the f i r s t paragraph
~ t h e
words "and'rated over 35,000 volts."
SUBSTANTIATION: Since there are no NEMAor ANSI Standards for
determining flammability, there are no test methods to determine
i f the various liquids meet the requirements of thls paragraph.
Preliminary tests made by Factory Mutual indicated that these
liquids failed the tests given to them. These liquidsdo burn
more readily than Askarel. Article 450-23 at the present time
permits transformers with these nonpropagatlng liquids being
placed in hazardous environments that contain flammable material
like paper dust, wood pulp, coal dust, etc. withoutrequiring
the use of a fireproof vault. Since a nonpropagating liquid can
burn for a period of time before the flame is extinguished,
paper dust, wood dust, coal dust, etc. could be ignited and
cause a f i r e even though the nonpropagating liquid went out. I t
is my understanding that at the present time there are no NEMA
or ANSI or any other Standard that covers the c r l t e r l a for
defining, testing and grading dielectric fluids used in
transformers where flammabl]ity is a c r i t i c a l factor. I t is
also my understanding that industry standards for such fluids
have never been formulated to insure safety and r e l i a b i l i t y .
I t would seem prudent that transformers containing these
liquids be placed in a fireproof vault until such time that
flammability standards have been developed and these liquids
tested and found satisfactory.
PANEL RECOI~ENDATION: Reject.
PANEL CDMM~NT: me supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANELRECO~ENDATION: U11animouslyAffirmative.
450-21: Accept
CMP 13
SUBMITTER: W. Creighton Schwan, Hayward, CA
PROPOSAL: 11 Designate the f i r s t two paragraphs as (a) and (b)
r e s p - ~ v e l y , and designate the two exceptions as Exceptions to
(b).
SUBSTANTIATION: Neither of the two exceptions apply to the
f i r s t paragraph. The suggested editorial revisions will
eliminate confusion for Code users.
PANEL RECOMMENDATION: Accept as Revised:
Assign t i t l e s to (a), (b), and (c).
l~I Not over 112 I/2 kVA.
Over 112 1/2 kVA
(c) Over 35,000 volts
Exceptions Nos. l and 2 shall apply to (b) only.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
212
450-23: Accept
CMP 13
Secretary's Note: I t was the action of the Correlating
Committee that further consideration be given to the comnents
expressed in the voting.
SUBMITTER: ~ 13
15A Revise f i r s t paragraph to read:
-'ITi-~--~'ire Polnt Liquid-Insulated Transformers. Traosformers
insulated with a liquid identified for use in nonconfoustible
buildings of a specific height, housing noncombustible
' occupancies, and having a f l r e point not less than 300°C shall
be permitted. Such transformers installed indoors and rated
over 35,000 volts shall be installed in a vault.
Delete second paragraph.
SUBSTANTIATION: Since all the Askarel substitutes developed to
date will burn to some degree, installations utilizing these
fluids should not be permitted in combustible buildings or those
housing combustible occupancies unless provided with an
automatic f i r e extinguishing system or installed in a vault.
The ability of a noncombustible building to withstand a
transformer insulating fluid f i r e depends upon the type of
construction (steel, concrete, etc.), building height, the
convective and radiative heat release rates per unit area of the
fluid and the surface area of the containment (curbing).
On that basis,leach installation should be evaluated
individually depending upon these four factors. The heat
release rates per unlt area should be determined by a recognized
testing laboratory in accordance with a standard procedure. I f
found excessive, than protection, In the form of an automatic
extinguishing system or a vault, should be provided similar to
that for a combustible building or occupancy.
Allowing the use of any substitute fluid without some form of
f i r e protection may, in some instances, result in a severe
exposure to l l f e and propertyshould an internal fault result in
a transformer f i r e .
PANEL RECOMMENDATION: Accept as Revised:
Revise 450-23 from NEC as follows:
i "Transformers insulated with a listed liquid having a fine
;point not less than 300°C shall be permitted to be installed
l indoors without vaults i f provided with a liquid confinement
a~ea and protected by an automatic f i r e extinguishing system.
Such transformers when installed indoors and rated over 35,000
volts shall be installed in a vault complying with Part C of
this Article.
"
Transformers installed outdoors shall comply with Section
450-27."
VqTE ON PANELRECOMMENDATION:
AFFIRMATIVE: g.
NEGATIVE: Boyd, Mattson, Thomas, Tudor.
COMMENTON VOTE:
ROBINSON: The purpose of this and similar proposals to the
1981 and earlier codes has been to promote the acceptance of a
safe alternate to ASKARELas a transformer insulating f l u i d for
use outside of vaults. While we believe the wording proposed
here is too restrictive, until such authorities as F.M. and U.L.
resolve the technical problems, we have no alternative, in the
interest of safety, but to support the Panel.
EXPLANATION OF VOTE:
BOYD: Am opposed to the panel proposal because i t does not
include provisions for less stringent requirements for a very
desirable "askarel substitute" which has been or may be
developed.
MATTSON: The 'intent of the Task Force I is lost in the
proposal as i t is worded.
An exception is needed to clarify the totalconcept. Tests
conducted by Factory Mutual Research indicate that some of the
high f i r e point insulated liquids are suitable for installation
in non-combustible buildings with non-combustible occupancies
without automatic f i r e extinguishing systems depending on the
heat release rate of the liquid and the height of the building.
The following is recommended: 450-23 (as is)
Exceptions: Transformers insulated with listed liquids
suitable for use in a non-combustlble building and a
non-combustible occupancy area shall be permitted to be
installed, without an automatic f i r e extinguishing system or
vault. (Remaining text of Proposal 15A - as is).
THOMAS: To approve this CMP recommendation, which wouJd
require ~hat al! l i q u i d - f i l l e d transformers containing a liquid
with a fire-point not less than 300°C be diked and sprinklered,
would be to ignore work that has been done and is s t i l l underway
at Factory Mutual Research. FMR is now evaluating substitute
liquids on the bas~s of" their use in non-combustible buildings
With non-combustible occupancies.
To approve this latest revision by" the CMP would be to violate
the spirit of what has been done and would create an
inconsistency between theNEC and what the insurers find
acceptable.
The original proposal, which recognizes the importance of the
building structure and its contents, is much more acceptable to
NEFtA. I t at least sets the stage for later to supply details in
the NEC such as building construction, roof height, building
contents, type of liquids, fire-point of liquids, etc.
TUDOR: The recommended rewording of the proposal by the panel
is too restrictive. The recommendation of the Subcommittee
investigating this proposal was that i f a transformer was
installed in accordance with the requirements of the listing of"
the liquid in the transformer, the unit could be installed
without an automatic f i r e extinguishing system or vault. No
increase in safety has been gained by the elimination of this
exception to the general rule.
Something has been lost, however. At the present time there
are millions of gallons of PCB's in Askarel-filled transformers
in this country. The Environmental Protection Agency has
promulgated rules which encourage the elimination of this
environmental hazard. By requiring an automatic f l r e
extinguishing system or vault for these transformers, should the
user decide to replace them with a high f i r e point
liquid-insulated tFaqsformer or to remove the PCB-containing
Askarel In a unit and replace i t with a high f i r e point liquid,
the proposed requirement will make i t economically unfeasible to
make this change. This, in turn, will mean that many
Askarel-fiIled transformers, which otherwise would have been
replaced or r e t r o f i l l e d , will remain in service, thereby
maintaining a serious environmental hazard and, incidentally,
subjecting the user to stringent reporting rules to the EPA and
forcing him to maintain a possibly catastrophic l i a b i l i t y on his
system.
450-23: Reject
CMP 13
SUBMITTEd: TSC-Neminal Voltage
PROPOSAL: 16" In the f i r s t paragraph add "nominal" after
~T~F~-O~-volts."
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECOI~ENDATION: Reject.
PANEL C~ENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOI~IENDATION: UnanimouslyAffirmative.
450-23: Reject
CMP 13
Secretary's Note: I t was the action of the Correlating
Co~ittee that this Proposal be correlated with Proposal No. 15A.
SUBMITTER: TSC-Approvedfor the Purpose
PROPO~ 17 See the Technical Subcommittee "Recommendations"
un--n-d-e-r-t-~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose= in Article 100.
PANEL RECOMMENDATION: Reject.
FANEL.COMMENT: See Panel action on Proposal No. 15A.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
450-23: Reject
CI~~ 13
SUBMITTER: Tor Orbeck, Dow Corning Corp.
PITO]~'At-~." 18 Revise as follows:
~[Io~0-~72-~-~-. Tranformers Installed Indoors. Transformers insulated
with an insulating liquid of "labeled" and "listed" f i r e
characteristics, having a f i r e point of nQt less than 300°C, and
"approved for the purpose" shall be permitted to be instaTled
indoors or outdoors. The required protection of such a
transformer installation is described in the "approval
principles" which relates f i r e characteristics o~ liquids to
potential f i r e hazards of transformers and determines which
insulating liquids can be used and the protection i f required.
Transformers rated over 35,000 volts and used indoors shall be
installed in a vault.
SUBSTANTIATION: I t is our understanding that to assess the f i r e
hazard of an insulating liquid in its use enviroment in an
electrical installation, i t is necessary to consider the
following characteristics of a material:
I. Ease of ignition - Flash point
Auto ignition temperature
Hot manifold ignition
Transformer explosion tests
2. Fire growth
- Fire point
'Large-scale f i r e tests
Transformer explosion tests
3. Elame s p r e a d
Large-scale
f i r e tests
4. Heat release
Heat of co~oustion
Rate of burning
,
Effects on materials and people
5. Extinguishment - Field tests
6. Smoke
NBS smoke chamber test
obscuration of vision
animal tests
{
eye i r r i t a t i o n
toxicity
7. Fire gases
- Qualitative and quantitative
(Smoldering and
analysis
burning conditions) Animal exposure tests
8. Oxygen depletion - Large-scale tests
Limiting oxygen index
(Effects on people)
The material evaluation must finally be related to use
environment through:
I. Consideration of appiication and quantities involved
2. Consideration of building and location of equipment
/
We also know that the Factory Mutual Research organization has
a project to develop principles by selecting the most important
of these test methods to be used for a listing or labeling
system for insulating liquids.
At present Section 450-23 reads as follows:
213
450-26: Accept
.
CMP 13
Secretary's Note: I t was the action of the Correlating
Committee that i t questions the need for all of the diagrams and
requests the Panel to review them to see i f they can be removed.
SUBMITTER: O. E. Dillon, Border County Oiv. IAEI
~ 2 2
Revise as follows:
~I~'~T~L~-6"~-.Oil,lnsulated Transformer Installed Outdoors.
Oil-Insulated transformers shall not be installed.
I . Within 3 feet horizontal distance of any building wall.
) 2.. Within 10 feet horizontal distance of any required exit.
3. Within 20 feet vertical distance of any building overhang.
4. Within 10 feet radial distance of any window.
The authority having Jurisdiction may consider fire-resistive
barrier, alternate sprinkler systems, etc., as equivalent
)rotection for the conditions so indicated.
SUBSTANTIATION: The vagueness of this language £enders this
section legally unenforceable~ See the attached opinion* of the
San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
i
PANEL RECOMMENDATION: Accept as Revised:
450-26. Oil-lnsulated Transformers Installed Outdoors.
Combustible material, combustible buildings and parts of
buildings, f i r e escapes, and door and window openings shall be
safeguarded from fires originating in oil-insulated transformers
installed on roofs, attached to, or adjacent to a building or
combustible material in conformance with the following:
(a) Space.Separatlonfor Non-Combustible Construction.
Oil-insulated transformers shall be permitted to be located
directly adjacent to non-combustible walls provided the
following clearances are maintained from doors, windows and
other building openings:
(1) Oil-lnsulated transformers shall not be'located within
a zone extending 20 feet outward and 10 feet to either side of a
building door. See Figure 1.
450-23. High Fire Point Liquid-insulated" Transformers.
Transformers insulated with a nonpropagating liquid approved for
the purpose, having a f i r e point not less than 3DO°C, shall be
permitted to be installed indoors or outdoors. Such
transformers installed indoors and rated over 35,0(0) volts shall
be installed in a vault.
For the purposes of this article, a nonpropagating liquid
shall be one which, when subjected to a source of ignition, may
burn but the flame will not spread from the source of ignition.
In this description the terms "high f i r e point liquid" and
"nonpropagating" do not adequately describe the above f i r e
characteristics of a liquid nor the associated f i r e hazard in
their electrical use environment.
• he proper description of the f i r e properties of a fiquid must
be strongly connected with the term "approved for the purpose."
This term is defined in Article 100 as follows:
Approved for the Purpose: Approvedfor a specific purpose,
environment, or application described in a particular Code
requirement.
Suitability of equipment or materials for a specific purpose,
environment or application may be determined by a nationally
recognized testing laboratory, inspec- tion agency or other
organization concerned with product evaluation as part of its
listing and labeling program. (See "Labeled" or "Llsted'.)
Labeled: Equipment or materials having a label, symbol, or
other identifying mark of a nationally recognized testing
laboratory, ihspection agency, or other organization concerned
with product evaluation that maintains periodic inspection of
production of labeled equipment or materials and by whose
labeling is indicated compliance with nationally recognized
standards or tests to determine suitable usage 4n a specified
manner.
Listed: Equipment or materials included in a l i s t published
by a nationally recognized testing laboratory, inspection
agency, or other organization concerned with product evaluation
that maintains periodic inspection of production of listed
equipment or materials, and whose listing states either that the
equipment or materials meets nationally recognized standards or
has been tested and found suitable for use in a specified manner.
The means for identifying listed equipment may vary for each
testing laboratory, inspection agency, or other organization
concerned with product evaluation, some of wMch do not
recognize equipment as listed unless i t is also labeled. The
authority having Jurisdiction should utilize the system employed
by the listing organization to identify a listed product.
Approval Principle: The term approval principle implies a
third party determination of selected f i r e characteristics, of
approved liquids and of required protection. We believe at the
present UL and FM have the capability to perform this function.
PANEL RECOMMENDATION: Reject.
PANEL ~OMHENT: See Panel action on Proposal No. 15A.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
F
,1,1,,111111,.
'
~
IAI
Villi/Ill
I
I II/ll//xl
,o,~ i ooo, i._,o,I
"i--"-w,o,.-'-/
#
/
/
'
Fi~ll'e I
j ...~lIL~.
(2) Ol1-1nsulated transformers shall not be located within
a zone extending 10 feet outward and 10 feet to either side of
an air intake opening. I f the air intake opening is above the
transformer, there shall be a 25 feet vertical distance from the
opening to the transformer. See Figure 2,
450-24: Reject
C~ 13
SUBMITTER: Charles B. Kish, The Travelers Insurance Co.
]IITOIIO~CL-~.19 Add a new second paragraph as follows: Areas
con--EnI'a'rnTng Askarel transformers should never have drain or other
pipe holes to the outside that would a11ow liquid to escape.
Proper diking or other means of containing total liquid spillage
should be constructed. Handling and disposal of spilled liquid
should be to legal guidelines.
SUBSTANTIATION: "Askarel" is a PCB (polychlorinated biphenyl)
which is sometimes mixed with chlorobenzene to glve particular
viscosity characteristics. PCB has been on the E.P.A.
(Environmental Protection Agency) Toxic Pollutant List for
several years. I t is an incredible stable chemical composition
that could gradually accumulate in certain ecological systems.
Any spillage would be a hazard to health and expenslve to clean
up.
PANEL RECOMMENDATION: Reject.
pANEL COMMENT: This Proposal could result in conflict with
later EPA Guldelines.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
7 NwOAI~70MBUSTIBLE
X
~llllilllllA
AIR INTAKEOPENING
' "lllliillllllillll~
t
(3) Oil-lnsulated transformers shall not be located within
a zone extending I0 feet outward and 3 feet to either side of a
building window or opening other than an air intake. See Figure
3.
450-24: Reject
?
CMP 13
SUBMITTER: TSC-Nominal Voltage
20 In the penultimate line add "nominal" after
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately,~eflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
•
NONCOMBUSTIBLEWALL FDOOR OPENING
ONCOMBUSTIBLE
"
~'NWALL
X
~l'illllllllllllJ
450-25, Exception No. 2: Accept
CMP 13
SUBMITTER: TSC-Nomlnal Voltage
21 Revise the f i r s t l i n e as f o l l o w s :
x~lon
No. 2: Where the nominal voltage does not exceed
]
VIIIIlIIIIJ
p;
WIDTH
[]
SUBSTANTIATION: To obtain unlformlty of voltage levels and
ratings throughout the Code.
PANEL RECOMMENDATION: Accept.
VOTEON PANELRECOIe~ENDATION: UnanimouslyAffirmative.
214
o
~.
•
600, etc.
WINDOWOPENING
'
Figure 3
(e) Oil Enclosures. Where oil frem a ruptured transformer
:tank can drain into the protected zones listed above, oil
enclosures that confine the oil shall be installed. Oil
enclosures shall be permitted to consist of f i r e resistant
dikes, curbed areas or basins, or trenches f i l l e d with coarse
stone. Oil enclosures shall be provided with trapped drains
where the exposure and quantity of oil is such that removal of
the oil is important.
(f) On Poles, Structures or Underground. Transformers
installed on poles, structures or underground shall conform to
the National Electrical Safety Code, ANSI C2-1977.
VOTE ON PANEL RECOICMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Jefferson, Mattson, Thomas.
EXPLANATION OF VOTE:
JEFFERSON: The f i r e potential of o i l - f i l l e d transformers is
well known and well-documented. However, I do not feel that
this proposal offers any improvement in safety over the present
code. The only factors considered are the type of building
construction. The proposal makes no distinction as to building
occupancy, residential, commercial or industrial; Building use;
does not consider proximity to structures other than
%uildings"; and does not consider the volume of oil present. I
also object to the format and feel i t is a bad precedent for the
NEC. I also anticipate a flood of future proposals, additions
and exceptions, attempting to address every conceivable building
feature. This proposal is in conflict with Article 90-1 (c)
which states, "This code is not intended as a design
specification nor an instruction manual for untrained persons."
MATTSON: Negative vote would change to an affirmative i f
recognition were to be made of size of the units. At presen~
450-26 allows any transformer to be installed in accordance with
t e x t . By changing the t i t l e the size could be limited.
I t is recognized that the intent of the proposal is for small
units. This philosophy may be lost or misinterpreted in the
future.
Suggest t i t l e be changed to: 450-26 Oil-lnsulated Transformer
Under 10,000 kVA Installed Outdoors.
lllOMAS: Although proposed revision provides additional
detail, t h e r e i s no technical substantiation for the selected
dimensions.
(4) Where the space separations above cannot be attained,
f i r e resistant barriers or automatic water spray systems shall
be permitted to be installed as safeguards. Where a barrier is
used, i t shall extend to a projection line from the corner of
the transformer to the furthest corner of the window, door or
i opening. The height of the barrier shall be I foot above the
t o p of the transformer. See Figures 4 and 5.
F
WINDOWOR OPENING
Jv////////////J
OST,8 WALL
\\
•
%
f
Jv///////////A
I
WINDOWOR OPENING
~
I
~1
~[-~1I
Figure 5
I
(b) Space Separation f o r Combustible Construction. ,
{1) Oil-insulated transformers rated 100 kVA or less shall
~e located according to the provisions set f o r t h f o r
noncombustible construction.
(2) Oil-insulated transformers of more than 100 kVA rating
shall be located according to the provisions set forth for
noncombustible construction but not closer than 10 feet from the
building wall.
(3) Where a roof of co(nbustible material or an overhang of
combustible material is 20 feet or more above the top of an
oil-insulated transformer, the required horizontal distances
shall be measured from the building wall. See Figure 6 Dimension "A." .
Where a roof of combustible material or an overhang of
combustible material is less than 20 feet above the top of an
oil-insulated transformer, the required horizontal distances
shall be measured from the farthest projection of the overhang.
SeeiFigure 6 - Dimension "B."
~
____
•I
/////
///. /
i
•
450-26, FPN-(New): Reject
CMP 13
SUBMITTER: Samuel S. Levinrad, VA, Wash., DC
~ 2 3
Add a fine print note as follows:
Transformer high pressure r e l i e f valves and high voltage
current limiting fuses are recognized safeguards for preventing
catastrophic transformer failure.
SUBSTANTIATION: I t is recommended that Section 450-26,
Oil-lnsulated Transformers Installed Enclosures, be revised to
be consistent with the latest technology and established
engineering practice. Oil-insulated transformers (padmount
transformers) are presently being installed adjacent to school
buildings, townhouses a~d single family residences. They are
installed in shopping center parking lots and in other areas
readily accessible to the general public.
S6ction 450-26 reflects the reco~endatfons contained in
"Recommended Good Practice for Transformer and Switchgear
Installations", published by Factory Mutual Insurance
Association. At the time that this document was written, i t was
the only guide for designers with respect to f i r e safety.
However, we feel i t should have been updated. Since the
National Electrical Code and NFPA have no jurisdiction in the
updating of the aforementioned document, i t is our feeling that
the National ElectriCal Code should become current with present
day practices. Today's emphasis for increased safety margins on
electric u t i l i t y distribution systems has led to a rapid growth
in the use of current-limiting fuses for the protection of
distribution systems.
Available distribution system fault current has increased
significantly because system voltages have increased, and higher
MVA capacity station transformers are being installed. This has
resulted in potential f a u l t duties that exceed the capability of
low-cost fuses historically used to protect distribution
transformers. A major limitation of the expulsion fuse is its
i n a b i l i t y to limit current; as a result, tremendous amounts of
energy can be fed into a fault. I f the fault occurs in a
transformer, there is the possibility of a disruptive failure
endangering l i f e and property. Current-limlting fuses offer a
unique advantage in their a b i l i t y to limit the let-through
current and energy within safe limits with silent, non-venting
operation. Thus, increased emphasis on safety (accelerated by
the development of pad~ounted equipment which can be applied in
close proximity to the general public) has caused u t i l i t y .
engineers to specify current-limiting fuses to prevent these
potentially violent tank failures. When a current-limiting fuse
is applied to a c i r c u i t , not only can the current be
substantially limited, but the arcing time is also decreased.
I t follows then that the energy imparted to a fault can be
l
substantially reduced, since i t is proportional to the
let-through current squared and the total clearing time. This
reduction of energy makes i t possible to protect distribution
equipment from disruptive failures and hence to improve system
safety margins. Consequently,'the a b i l i t y of the transformer t o
,withstand faults without catastrophic failure can be immensely
improved through the.proper application of current-limiting
Figure 6
._~LEARANCE
A"
///////////
(4) Where these space separations cannot be attained,
fire-resistant barriers or automatic water spray systems shall
be permitted to be installed as the required safeguards. Where
a barrier is used, i t shall extend 3 feet beyond each side of
the transformer. The height of the barrier shall be 1 foot
above the top of the transformer. See Figure 7.
f
COMBUSTIBLEWALL (SOLIDOR WITH WINDOWOR OPENING)
~v/////////
ll//////
/ /////~
Figure 7
(c) On Roofs. Oil-insulated transformers installed on roofs
shall meet the requirements of this section and the floor
requirements of Section 450-42.
(d) Fire Escapes. Oil-insulated transformers shall be
located such that a minimum clearance of 20 feet is maintained
from f i r e escapes at all times.
215
)
fuses.
PANEL RECOMMENDATION: Reject.
PANELCOMMENT: Transformer high pressure r e l i e f valves are a
requirement of ANSI C57.12.22-1969. The use of high voltage
current limiting fuses is a system design consideration.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-27-(New): Reject
CMP 13
SUBMITTER: O. E. Dillon, Border County Div. IAEI
PROPOSAL: 24 Add new section as follows:
TS"O'z'27q- . Installation of Transformers in Outdoor Enclosure:
General. Where transformers are installed in an outdoor
enclosure, the enclosure shall consist of a substantial fence
not less than 8 feet high. The fence shall be so constructed
that persons cannot readily climb i t . Where any exposed
current-carrying part is more than 8 feet above the ground, the
height of the fence shall be not less than 10 feet, unless the
Fence is located more than 5 feet horizontally from the nearest
such current-carrying part. The fence i f of metal shall be
grounded in accordance with Article 250. The gate shall be kept
locked, and a permanent sign legible at 12 feet shall be posted
on the gate, gorbidding unauthorized persons to enter. No fence
shall be required where all current-carrying conductors and
parts entering the transformers are lead-sheathed and protected
from physical damage, or are enclosed in metal raceway; the
sheath, or the metal raceway, shall be wiped-in or screwed to
the transformer cases, making a watertight construction, and all
sheaths or raceways and the cases of the transformers shall be
effectively grounded.
When the enclosure is adjacent to platforms, balconies, roofs,
windows or doors, suitable screens shall be provided to prevent
persons coming into contact with current-carrying parts, or
bring conducting materials into contact with them.
SUBSTANTIATION: The vagueness of this language renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Already covered by Sections 110-30 through
110-34, No additional clarification would be achieved by this
proposal.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-27-(New): Accept
CMP 13
SUBMITTER: John C. Dutton, Rome, GA
][R-O-PD-~ki-?.
• 25
Noncombustible Insulant Transformers. Transformers
with a noncombustible dielectric fluid approved for the purpose
shall be permitted to be installed indoors or outdoors. Such
transformers.installed indoors and rated over 35000 volts shall
be installed in a vault.
For the purposes of this section, a noncombustible dielectric
fluid is one which does not have a flash point or autoignition
temperature, and is not flammable in air.
SUBSTANTIATION: Recent regulatory actions have eliminated the
use of PCB's (one of the constituents of askarel liquids) in new
transformers, requiring the development of new types of
transformers and the formulation of new dielectrics.
The wording of NEC Article 450, Part B is the basis for
acceptance of stated transformer designs and specified
dielectrics. Transformers using a noncombustible dielectric
fluid are available, and the proposed NEC section will provide
acceptance of installations utilizing these new types of
transformers.
PANEL RECOMMENDATION: Accept as Revised:
Change lines I-3 to read: Nonflammablefluid-insulated
transformers. Transformers insulated with a dielectric fluid
identified as nonflammable shall be..." In second paragraph,
change the word "noncombustible" to "nonflammable." Renumber
from "450-27" to "450-24." Renumberexisting 450-24, 450-25,
and 450-26 to 450-25, 450-26 and 450-27.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 12.
NEGATIVE: Thomas.
EXPLANATION OF VOTE:
THOMAS: The revision of this section, as proposed by CMP-13,
would be acceptable I f the proposed second paragraph were
revised as follows:
For the purposes of this section, a nonflammable dielectric
fluid is one which does not have a flash point or f i r e point
below boiling and has an autoignltion temperature greater than
lO00°F (538°C).
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Panel feels subject is adequately covered.
VOTE ONPANEL RECOMMENDATION: 'Unanimously Affirmative.
450-29-(New): Reject
CMP 13
SUBMITTER: O. E. Dillon, Border County Div. IAEI
27 Add new section as follows:
~[5~0U~2"9-[ . Installation of Transformers on a Roof. Transformers
may be installed on the roof of a building, where the structure
of the building is of sufficient strength to carry the
additional weight of the transformers and their enclosures and
the equipment used in connection therewith under the following
conditions:
(a) Dry-type and askarel-insulated transformers shall be in
approved weatherproof enclosures.
(b) Where oil-insulated transformers are installed and the
roof is of two-hour flre-resistlve construction, the enclosure
shall conform to Sub-article 450-C, as applicable. Where a
fence enclosure is provided, a curb shall be provided high
enough to contain the oil from the largest of the o i l - f i l l e d
transformers, but in no case less than six inches high. A drain
shall be provided from the enclosures to carry any oll which i t
may contain well away from the building. Where the roof is not
of two-hour flre-resistlve construction, the enclosures shall
conform to Sub-article 450-C, as applicable.
SUBSTANTIATION: The vagueness of this language renders thls
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject;
PANEL COMMENT: The intent is covered by Panel action on
Proposal No. 22.
VOTE ON PANELRECOMMENDATION: UnanlmouslyAffirmative.
450-41: Reject
CNP 13
SUBMITTER: O. E. Dillon, Border County Oiv. IAEI
28 Delete450-41.
~]B~-YA-N~'IATION: The use of the word "practicable" renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
*See Border County Div. IAEI substantiation for proposal for
110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450~42, Exception: Reject
CMP 13
SUBMITTER: JeromeM. Frank Sorgel, Div/Square D Co.
29 Delete the exception.
~O~-~TANTIATION: Section 450-25 requires that oll-lnsulated
transformers installed indoors be placed in a vault. The tank
of an o i l - f i l l e d transformer under fault conditions can rupture
and burning oil can be emitted. Oil floats on water and burning
oil would float on water and spread throughout a building.
It
does not make engineering sense to reduce the flre-resistance
rating from three hours down to one hour under the above
conditlons.
In addition, since transformer vaults contain other electrical
gear which could produce serious and hazardous conditions i f
exposed to water, automatic sprinkling of vaults containing
electrical equipment is highly undesirable and should not be
permitted by the Natlonal Electrical Code.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not agree with the supporting
comment.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-42, Exception: Accept
CMP 13
SUBMITTER: Arthur F. Clchy, Fenwal, Inc., Ashland, MA
~
30 Revise exception as follows:
x - - - ~ - ~ l o n : Where transformers are protected with automatic
sprinkler, water spray, carbon dloxtde or halon, construction of
one-hour rating shall be permitted.
SUBSTANTIATION: Since the writing of thts code, halon has been
selected as the extinguishing agent on numerous transformer
vault installations. As an exemple, attached sheets
representing installations in transformer vaults by ~emval, Inc.
have been supplied to the panel.
PANEL RECOMMENDATION:
Accept.
VOTE ON PANEL RECOMMENDATION:
Unanimously Affirmative.
COMMENTON VOTE:
BECKMANN: Reco,mend"vault" be added before "construction."
I
450-28-(New): Reject
CMP 13
SUBMII-[ER: O. E. Dillon, Border County Div. IAEI
26 Add new section as follows:
Installation of Transformers on Poles. Where
transformers are installed on poles or pole structures, ANSI
C2-1977, Rules fop Overhead Electric Line Construction of the
California Public U t i l i t i e s Commission shall apply.
SUBSTANTIATION: The vagueness of thls language renders thls
216
balanced load should, necessarily be protected against possible
damage from a r b i t r a r i l y applying an unbalanced load which does
not exceed the nominal rated load of the transformer but may
seriously overload portions of its windings.
SUBSTANTIATION: I believe that the trade magazines, In the last
year or so, have cultivated a hopeless state of confusion in the
minds of many electrical inspectors and electrical engineers
about the Code requirements which apply to the installation of
transformers. In essence, the thrust of the published articles
seems to have i t that the Code required primary overcurrent
protection called for in Section 450 must be augmented, as a
general rule, by secondary-slde overcurrent devices to protect
the "secondary circuit conductors" to conform to Section 240
regardless of th E ampacity of these conductors, the rating of
the transformer or the maximumcurrent that the primary
overcurrent would permit to become available to the secondary
terminals 'under any arbitrarily imposed load conditions.
I t seems to be ignored, that there is generally no reason to
expect that a transformer serving a normally balanced load will
ever have the load spontaneously revert to any seriously
unbalanced condition due to some secondary circuit defect. In
other words, there is no reason to expect that the complication
or added expense of providing secondary overcurrent protection
can be Justified as anything other than an academic argument.
In the final analysis, any person sufficiently inept to
intentionally apply a seriously unbalanced load to a susceptible
transformer could be expected to also bypass the safeguards
intended to protect either the transformer or circuit conductors.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel is uncertain of the intent of the
Proposal.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-43, Exception: Accept
CMP 13
SUBMITTER: Arthur F. Cichy, Fenwal, Inc., Ashland, MA
FR-O-PO~I~C~." 31 Revise exception as follows:
x--E'-x~eptiOn: Where transformers are protected with automatic
sprinkler, water spray, carbon dioxide or halon, construction of
one-hour rating shall be permitted.
SUBSTANTIATION: Since the writing of this code, halon has been
selected as the extinguishing agent on numerous transformer
vault installations. As an example, attached sheets
~/
representing installations in transformer vaults by Fenwal, Inc.
have been supplied to the panel.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-43(b): Reject
CMP 13
SUBMITTER: D. F. Wartzok, Fort Wayne, IN
!~R-O-PO-S-AL: 32 Add a new paragraph to existing subpart (b) as
A vault for transformers using PCB-based cooling fluid shall
have a door s i l l or curb of sufficient height to confine within
the vault the fluid from a l l of the transformers. End of
conduits extending through the floor shall be at a height not
less than the door s i l l or curb height.
SUBSTANTIATION: The Federal Toxic Substances Control Act
contains specific requirements regarding the handling and
disposal of polychlorlnated biphenyls, commonly known as PCB's
which are considered hazardous to the environment. Large
liquld-cooled transformers sometimes contain a cooling fluid
which is based on PCB.
The present wording in Article 450-43(b) does not adequately
protect against the escape of PCB-based transformer cooling
fluids into the environment. The proposed additional paragraph
specifies vault construction so that the PCB-based transformer
cooling fluid from all transformers in a vault (instead of Just
the largest) will b~dequately retained in case of transformer
tank rupture or leakage, until i t can be cleaned up.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: This Proposal could result in conflict with
later EPA Guidelines.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 460 -- CAPACITORS
460-6(a): Accept
~
13
SUBMITTER: TSC-Nominal Voltage
I
~
36 In the second line add "nominal" after "50 volts."
~7]I~SnFA-N7"IATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450145(e): Accept
CMP 13
SUBMITTER: J. Brooks Semple, ASHRAE/NFPAStd. 90A
~AL:
33 Delete "automatic closing dampers of not less
than No. 10 MSG steel." Insert "Fire dampers which comply with
Paragraph 3-3.7.1.2 of NFPA90A.N
SUBSTANTIATION: 1. Present wording does not comply with other
NFPA standards
2. IOMSGsteel is a material specification and there is no
substantiation of its effectiveness to stop f i r e .
3. Para. 3-3.7.1.2 is a performance specification which
includes substantiation of its effectiveness.
PANEL RECOMMENDATION: Accept as Revised:
(el Dampers. All ventilation openings to the indoors shall be
provided with automatic closing f i r e dampers that operate in
response to a vault f i r e . Such dampers shall possess a standard
f i r e rating of not less than 1 I/2 hours. Fine Print Note: See
Standard for Fire Dampers, ANSI Z233.1-1972.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
460-Part A: Accept
CMP 13
SUBMITTER: C~ 13
I~TOI}I~'AL-~.
• 36A Revise Title of Part A to read: 600 Volts,
and Under.
SUBSTANTIATION: To comply with the Technical Subcommittee
recommendation on nominal voltages.
PANEL RECO~'6VlEMDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
460-7: Accept
CMP 13
SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.
I}IIOI~)-S'A-L-~:37 Revise as follows:
~Power
Factor Correction-Motor Circuit. The total
kilovar rating of capacitors that are connected on the load side
of a motor controller shall not exceed the value required to
raise the no-load power factor of the motor to unity.
Capacitors so connected shall be permitted only in applications
where the motor is not subject to unusual switching service such
as plugging, rapid reversals, reclosings, Jogging, or other
similar operations which could generate over-voltages and
over-torques.
Delete the exception.
SUBSTANTIATION: The service conditions cited in italicized
"Exceptionu as not permitted when capacitors not exceeding 50
percent of the kVA rating of the motor input are used are
equally unacceptable when capacitor rating is selected on basis
of limiting motor no-load power factor to unity. We believe
these application guides have been followed in the past when
using capacitors for motor power factor correction~ Citing the
unacceptable service conditions only in the italicized
"Exception," by inference, implies such service conditions are
acceptable when capacitor rating is set to limit motor no-load
power factor to unity. With capacitor ratings so set and with
capacitors connected on load side of motor controller,
over-voltages and over-torques could also be generated i f the
motor is subject to plugging, rapid reversals, rec)osings,
Jogging, etc.
I f capacitor ratings up to 50 percent of the kVA rating of the
motor input are permitted to be connected on load side of motor
controller, the motor is subjected to an over-voltage limited
only by saturation ~ach time the motor is disconnected. These
over-voltages may range from 1.2 to 1.6 times normal voltage and
will contribute to premature failure of the motor insulation
system.
.Moreover, setting capacitor rating as 50 percent of the kVA
rating of the motor input does not afford, in most cases, an
appreciable gain in power factor over that achieved by setting
capacitor rating to limit motor no-load power factor to unity.
In support of the preceding sentence, Exhibit A (attached)
450-46, Exception-(New): Reject
CMP 13
SUBMITTER: Charles B. Kish, The Travelers Insurance Co.
34 Add a new exception as follows:
~ i o n :
Areas containing Askarel transformers should never
have drain or other pipe holes to the outside that would allow
liquid to escape. Proper diking or other means of containing
total liquid spillage should be constructed. Handling and
disposal of spilled liquid should be to legal guidelines.
SUBSTANTIATION: "Askarel" is a PCB (polychlorinated biphenyl)
which is sometimes mixed with chlorobenzene to give particular
viscosity characteristics. PCB has been on the E.P.A.
(Environmental Protection Agency) Toxic Pollutant List for
several years. I t Is an incredible sta~le chemical composition
that could gradually accumulate in certain ecological systems.
Any spillage would be a hazard to health and expensive to clean
up.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: This Proposal could result in conflict with
later EPA Guidelines.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-XX: Reject
CMP 13
SUBMITTER: R. C. Cathcart, Kalamazoo, MI
35 AmendSection 450 to state specifically the
~ f
the NEC with respect to protecting the primary and
secondary transformer windings (themselves) frem overcurrent,
with the object being to make a clear distinction from the
overcurrent consideration for the primary and secondary circuit
conductors which are involved with tranformer installations.
This should focus on whether transformers designed for a
217
balanced load should, necessarily be protected against possible
damage from a r b i t r a r i l y applying an unbalanced load which does
not exceed the nominal rated load of the transformer but may
seriously overload portions of its windings.
SUBSTANTIATION: I believe that the trade magazines, In the last
year or so, have cultivated a hopeless state of confusion in the
minds of many electrical inspectors and electrical engineers
about the Code requirements which apply to the installation of
transformers. In essence, the thrust of the published articles
seems to have i t that the Code required primary overcurrent
protection called for in Section 450 must be augmented, as a
general rule, by secondary-slde overcurrent devices to protect
the "secondary circuit conductors" to conform to Section 240
regardless of th E ampacity of these conductors, the rating of
the transformer or the maximumcurrent that the primary
overcurrent would permit to become available to the secondary
terminals 'under any arbitrarily imposed load conditions.
I t seems to be ignored, that there is generally no reason to
expect that a transformer serving a normally balanced load will
ever have the load spontaneously revert to any seriously
unbalanced condition due to some secondary circuit defect. In
other words, there is no reason to expect that the complication
or added expense of providing secondary overcurrent protection
can be Justified as anything other than an academic argument.
In the final analysis, any person sufficiently inept to
intentionally apply a seriously unbalanced load to a susceptible
transformer could be expected to also bypass the safeguards
intended to protect either the transformer or circuit conductors.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel is uncertain of the intent of the
Proposal.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-43, Exception: Accept
CMP 13
SUBMITTER: Arthur F. Cichy, Fenwal, Inc., Ashland, MA
FR-O-PO~I~C~." 31 Revise exception as follows:
x--E'-x~eptiOn: Where transformers are protected with automatic
sprinkler, water spray, carbon dioxide or halon, construction of
one-hour rating shall be permitted.
SUBSTANTIATION: Since the writing of this code, halon has been
selected as the extinguishing agent on numerous transformer
vault installations. As an example, attached sheets
~/
representing installations in transformer vaults by Fenwal, Inc.
have been supplied to the panel.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-43(b): Reject
CMP 13
SUBMITTER: D. F. Wartzok, Fort Wayne, IN
!~R-O-PO-S-AL: 32 Add a new paragraph to existing subpart (b) as
A vault for transformers using PCB-based cooling fluid shall
have a door s i l l or curb of sufficient height to confine within
the vault the fluid from a l l of the transformers. End of
conduits extending through the floor shall be at a height not
less than the door s i l l or curb height.
SUBSTANTIATION: The Federal Toxic Substances Control Act
contains specific requirements regarding the handling and
disposal of polychlorlnated biphenyls, commonly known as PCB's
which are considered hazardous to the environment. Large
liquld-cooled transformers sometimes contain a cooling fluid
which is based on PCB.
The present wording in Article 450-43(b) does not adequately
protect against the escape of PCB-based transformer cooling
fluids into the environment. The proposed additional paragraph
specifies vault construction so that the PCB-based transformer
cooling fluid from all transformers in a vault (instead of Just
the largest) will b~dequately retained in case of transformer
tank rupture or leakage, until i t can be cleaned up.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: This Proposal could result in conflict with
later EPA Guidelines.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 460 -- CAPACITORS
460-6(a): Accept
~
13
SUBMITTER: TSC-Nominal Voltage
I
~
36 In the second line add "nominal" after "50 volts."
~7]I~SnFA-N7"IATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450145(e): Accept
CMP 13
SUBMITTER: J. Brooks Semple, ASHRAE/NFPAStd. 90A
~AL:
33 Delete "automatic closing dampers of not less
than No. 10 MSG steel." Insert "Fire dampers which comply with
Paragraph 3-3.7.1.2 of NFPA90A.N
SUBSTANTIATION: 1. Present wording does not comply with other
NFPA standards
2. IOMSGsteel is a material specification and there is no
substantiation of its effectiveness to stop f i r e .
3. Para. 3-3.7.1.2 is a performance specification which
includes substantiation of its effectiveness.
PANEL RECOMMENDATION: Accept as Revised:
(el Dampers. All ventilation openings to the indoors shall be
provided with automatic closing f i r e dampers that operate in
response to a vault f i r e . Such dampers shall possess a standard
f i r e rating of not less than 1 I/2 hours. Fine Print Note: See
Standard for Fire Dampers, ANSI Z233.1-1972.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
460-Part A: Accept
CMP 13
SUBMITTER: C~ 13
I~TOI}I~'AL-~.
• 36A Revise Title of Part A to read: 600 Volts,
and Under.
SUBSTANTIATION: To comply with the Technical Subcommittee
recommendation on nominal voltages.
PANEL RECO~'6VlEMDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
460-7: Accept
CMP 13
SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.
I}IIOI~)-S'A-L-~:37 Revise as follows:
~Power
Factor Correction-Motor Circuit. The total
kilovar rating of capacitors that are connected on the load side
of a motor controller shall not exceed the value required to
raise the no-load power factor of the motor to unity.
Capacitors so connected shall be permitted only in applications
where the motor is not subject to unusual switching service such
as plugging, rapid reversals, reclosings, Jogging, or other
similar operations which could generate over-voltages and
over-torques.
Delete the exception.
SUBSTANTIATION: The service conditions cited in italicized
"Exceptionu as not permitted when capacitors not exceeding 50
percent of the kVA rating of the motor input are used are
equally unacceptable when capacitor rating is selected on basis
of limiting motor no-load power factor to unity. We believe
these application guides have been followed in the past when
using capacitors for motor power factor correction~ Citing the
unacceptable service conditions only in the italicized
"Exception," by inference, implies such service conditions are
acceptable when capacitor rating is set to limit motor no-load
power factor to unity. With capacitor ratings so set and with
capacitors connected on load side of motor controller,
over-voltages and over-torques could also be generated i f the
motor is subject to plugging, rapid reversals, rec)osings,
Jogging, etc.
I f capacitor ratings up to 50 percent of the kVA rating of the
motor input are permitted to be connected on load side of motor
controller, the motor is subjected to an over-voltage limited
only by saturation ~ach time the motor is disconnected. These
over-voltages may range from 1.2 to 1.6 times normal voltage and
will contribute to premature failure of the motor insulation
system.
.Moreover, setting capacitor rating as 50 percent of the kVA
rating of the motor input does not afford, in most cases, an
appreciable gain in power factor over that achieved by setting
capacitor rating to limit motor no-load power factor to unity.
In support of the preceding sentence, Exhibit A (attached)
450-46, Exception-(New): Reject
CMP 13
SUBMITTER: Charles B. Kish, The Travelers Insurance Co.
34 Add a new exception as follows:
~ i o n :
Areas containing Askarel transformers should never
have drain or other pipe holes to the outside that would allow
liquid to escape. Proper diking or other means of containing
total liquid spillage should be constructed. Handling and
disposal of spilled liquid should be to legal guidelines.
SUBSTANTIATION: "Askarel" is a PCB (polychlorinated biphenyl)
which is sometimes mixed with chlorobenzene to give particular
viscosity characteristics. PCB has been on the E.P.A.
(Environmental Protection Agency) Toxic Pollutant List for
several years. I t Is an incredible sta~le chemical composition
that could gradually accumulate in certain ecological systems.
Any spillage would be a hazard to health and expensive to clean
up.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: This Proposal could result in conflict with
later EPA Guidelines.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
450-XX: Reject
CMP 13
SUBMITTER: R. C. Cathcart, Kalamazoo, MI
35 AmendSection 450 to state specifically the
~ f
the NEC with respect to protecting the primary and
secondary transformer windings (themselves) frem overcurrent,
with the object being to make a clear distinction from the
overcurrent consideration for the primary and secondary circuit
conductors which are involved with tranformer installations.
This should focus on whether transformers designed for a
217
depicts motor power factor improvement over load range from 0 to
125 percent load with corrective kVAR at value to:
(a) raise motor no-load power factor to unity;
(b) equal 50 percent of the kVA rating of the motor input.
In the f i r s t two examples depicted, 7.5 HP, 1200 RPM & 10 HP,
900 RPM ratings, the motor no-load KVARis more than 50 percent
of the kVA rating of the motor input. In these cases, which are
typical of ones having inherently low motor power factor and
where power factor improvement would be most beneficial, the
italicized "Exception" is simply not applicable and thus affords
no potential for additional gain in power factor improvement.
In the second two examples, 40 HP, 1200 RPM & 200 HP, 1800 RPM
ratings, corrective kVAR as value to raise motor no-load power
factor to unity yeilds better power factor improvement up
through 75 percent load than attained by corrective KVARequal
to 50 percent of the kVA rating of the motor input. For loads
above 75 percent, the converse is true, but there is no notable
overall difference ih power factor improvement between the two
approaches.
I PANEL RECOMMENDATION: Accept as Revised:
Insert in f i r s t sentence between "motor to" the words "branch
circuit."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Beckmann,Jefferson, Tudor.
EXPLANATION OF VOTE:
BEC!<MANN: I rejected this proposal because I believe that
insufficient documentation has been received to Justify changing
the Code for motors rated 600 volts nominal or less and not
exceeding 50 HP. Documentation has been received from Industry
indicating l i t t l e or no trouble from using the present Code at
these ratings.
I would agree to accepting the proposed change i f i t included
the following exception:
Exception: Whenmotor ratings do rbot exceed 600 volts nominal
and 50 horsepower; capacitors not exceeding 50 percent of the
kVA rating of the motor input shall be permitted to be connected
on the load side of the motor controller.
JEFFERSON: I agree with NEMAthat the wording of the
exception in the present code can and has led to improper
interpretation of the entire article. However, I do not think
this proposal is the solution to the problem. The effect of the
entire article is to restrict the optimum use of capacitors by
attempting to reduce the potential for errors by untrained
persons. As a compromise, shbrt of eliminating the article, I •
could support an article consisting of the First sentence of the
proposal as revised and adding a fine print note pointing out
the necessity for special consideration when the motor is
subject to unusual switching service.
TUDOR: This proposal is unnecessarily restrictive. The
present requirements are sufficient for a safe installation.
460-7: Reject .
CM@ 13
SUBMITTER: E. Griffy, I l l , Oklahoma City, OK
]~-O!51~TA-C~•. 38 Revise to read:
The total kIlovar rating of capacitors that are connected on
the load side of a motor controller shall not exceed the value
required to raise the power factor of the motor branch circuit
to unity.
SUBSTANTIATION: Nothing can be done to change the power factor
of the MOTORunless Capacitors are interposed in the Motor
Windings, or, Power Factor Improvement Capacitors are attached
to the Motor Housing or, incorporated within the Motor Housing,
or, the Motor is a Synchronous Motor. The ONLY "Power Factor"
that is altered is the Power Factor of the Motor Branch Circuit.
I'm sure you'll agree that the wording of the National
Electrical Code should be as technically correct as humanly
ossible to avoid confusing those users of the National
lectrical Code who are not current-"Capacitor," or, Motor
Engineers, and who, not being fluent with vector algebra, might
be misled by the present wording.
I recognize the t i t l e of 460-7 includes the wording "motor
circuit, ° but feel my suggestion is a warranted improvement.
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal; see
action on Proposal No. 37.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
The most important reason for this change is that single pole
switching of low voltage capacitors is hazardous. Single pole
equipments are usually open type knife switches where normal
switching or closing on faults could cause arcs, splattering
molten metal or flying parts. The workman may not open all
ungrounded poles and leave the capacitor energized when i t
should be de-energized.
PANEL RECOMMENDATION: Accept as Revised:
I Change(2) to read: "The disconnecting means shall open all
ungrounded conductors simultaneously." The rest of the Code
remains the same.
VOTE ON PANELRECOI~ENDATION: UnanimouslyAffirmative.
ARTICLE 470 -- RESISTORSAND REACTORS
CMP 13
470, Part A: Reject
SUBMITTER: TSC-Nominal Voltage
PROPOSAL: 40 Revise the t i t l e as Follows:,
~ 0 0
Volts, Nominal, or Less
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 710 -- OVER600 VOLTS, NOMINALGENERAL
710-2: Reject
CFP 13
SUBMITTER: H.K. Glenn, Pacific Coast Electrical Assn.
~ 4 1
Revise as follows:
Provisions applicable to specific types of installation are
included in Section 710-2 interrupting rating and. . . .
SUBSTANTIATION: The Pacific Coast Electrical Association has ,
~~p-roposal
to Panel No. I Section 110-9 proposing that
closing and momentary ratings be added to that section to cover
all devices that interrupt current at fault levels. We believe
that interrupting rating should be covered in one place only,
namely Section 110-9. See Pacific Coast Electrical Assn.
proposal for Section 710-21.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not agree with the supporting
comment.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
710-I: Accept
CMP 13
SUBMITTER: C~ 13
I
~
41A Add the word "nominal" after 600 volts. .
~'I]I~'FA}[TIATION: To'comply with the Technical Subcem~nittee's
recommendations on nominal voltage.
PANEL RECOMMENDATION: Accept.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
CMP 13
710-2: Accept
SUBMITTER: TSC - Skin Effect Current Tracing
P-h--O-P~-~A~-~-.'42 Add "Article 427, Fixed Electric Heating
~ t
for Pipelines and Vessels."
SUBSTANTIATION: To correlate with proposed revisions for
Article 427.
PANEL RECOI~ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
l
710-2: Accept
C~ 13
SUBMITTER: C~ 13
I~TO-h-O-S~A-CT.4
' 2A Add "Article 364, Busways" to Article 710-2 after
X-~'T'c~-'347, Rigid Nonmetallic Conduit.
SUBSTANTIATION: To be consistent with panel action on Proposal
No. 44.
PANEL RECOI~ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
460-B(c)(1),(2),and(3):
Accept
C~ 13
SUBMITTER: Stanley K. Hall, Duquesne Light Company
]~-OII~'TAt-~.
• 39 Revise as follows:
-~isconnecting
Means.
(I) A disconnecting means shall be provided in each
ungrounded conductor to simultaneously open all ungrounded
conductors for each capacitor bank.
(2) The disconnecting means shall be permitted to
disconnect the capacitor from the line as a regular operating
procedure.
(3) The rating of the disconnecting means shall not be less
than 135 percent of the rated current of the capacitor.
SUBSTANTIATION: This proposal will eliminate single pole
switching of low voltage capacitors. This practice is already
obsolete and not in general use. This is already a requirement
for capacitors over 600 volts. Art. 460-24 (a).
710-3(a) and (b): Accept
CMP 13
SUBMITTER: H. F. van der Voort, Cleveland, OH
l~J~rO-F~B~-~." 43 Add the words "in rigid nonmetallic conduit u t o
the f i r s t sentence, paragraph "(a) Aboveground Conductors" after
"in intermediate metal conduit" and before "in cable trays."
In paragraph "(b) Underground Conductors," amend the last
sentence before Table 710-3(b) b~ deleting the words "encased in
not less than 3 inches of concrete."
SUBSTANTIATION: Schedule40 rigid PVC conduit is suitable in
applications where the potential exceeds 600 volts. High
voltage, high current short circuit tests were conducted on 4
inch Schedule 40 Rigid PVC Conduit under a wide •range of
conditions. The results prove that the conduit exhibits l i t t l e
or no signs of deterioration or physical damage due to the
explosions and high temperatures. The report of the results of
218
\
depicts motor power factor improvement over load range from 0 to
125 percent load with corrective kVAR at value to:
(a) raise motor no-load power factor to unity;
(b) equal 50 percent of the kVA rating of the motor input.
In the f i r s t two examples depicted, 7.5 HP, 1200 RPM & 10 HP,
900 RPM ratings, the motor no-load KVARis more than 50 percent
of the kVA rating of the motor input. In these cases, which are
typical of ones having inherently low motor power factor and
where power factor improvement would be most beneficial, the
italicized "Exception" is simply not applicable and thus affords
no potential for additional gain in power factor improvement.
In the second two examples, 40 HP, 1200 RPM & 200 HP, 1800 RPM
ratings, corrective kVAR as value to raise motor no-load power
factor to unity yeilds better power factor improvement up
through 75 percent load than attained by corrective KVARequal
to 50 percent of the kVA rating of the motor input. For loads
above 75 percent, the converse is true, but there is no notable
overall difference ih power factor improvement between the two
approaches.
I PANEL RECOMMENDATION: Accept as Revised:
Insert in f i r s t sentence between "motor to" the words "branch
circuit."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 10.
NEGATIVE: Beckmann,Jefferson, Tudor.
EXPLANATION OF VOTE:
BEC!<MANN: I rejected this proposal because I believe that
insufficient documentation has been received to Justify changing
the Code for motors rated 600 volts nominal or less and not
exceeding 50 HP. Documentation has been received from Industry
indicating l i t t l e or no trouble from using the present Code at
these ratings.
I would agree to accepting the proposed change i f i t included
the following exception:
Exception: Whenmotor ratings do rbot exceed 600 volts nominal
and 50 horsepower; capacitors not exceeding 50 percent of the
kVA rating of the motor input shall be permitted to be connected
on the load side of the motor controller.
JEFFERSON: I agree with NEMAthat the wording of the
exception in the present code can and has led to improper
interpretation of the entire article. However, I do not think
this proposal is the solution to the problem. The effect of the
entire article is to restrict the optimum use of capacitors by
attempting to reduce the potential for errors by untrained
persons. As a compromise, shbrt of eliminating the article, I •
could support an article consisting of the First sentence of the
proposal as revised and adding a fine print note pointing out
the necessity for special consideration when the motor is
subject to unusual switching service.
TUDOR: This proposal is unnecessarily restrictive. The
present requirements are sufficient for a safe installation.
460-7: Reject .
CM@ 13
SUBMITTER: E. Griffy, I l l , Oklahoma City, OK
]~-O!51~TA-C~•. 38 Revise to read:
The total kIlovar rating of capacitors that are connected on
the load side of a motor controller shall not exceed the value
required to raise the power factor of the motor branch circuit
to unity.
SUBSTANTIATION: Nothing can be done to change the power factor
of the MOTORunless Capacitors are interposed in the Motor
Windings, or, Power Factor Improvement Capacitors are attached
to the Motor Housing or, incorporated within the Motor Housing,
or, the Motor is a Synchronous Motor. The ONLY "Power Factor"
that is altered is the Power Factor of the Motor Branch Circuit.
I'm sure you'll agree that the wording of the National
Electrical Code should be as technically correct as humanly
ossible to avoid confusing those users of the National
lectrical Code who are not current-"Capacitor," or, Motor
Engineers, and who, not being fluent with vector algebra, might
be misled by the present wording.
I recognize the t i t l e of 460-7 includes the wording "motor
circuit, ° but feel my suggestion is a warranted improvement.
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal; see
action on Proposal No. 37.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
The most important reason for this change is that single pole
switching of low voltage capacitors is hazardous. Single pole
equipments are usually open type knife switches where normal
switching or closing on faults could cause arcs, splattering
molten metal or flying parts. The workman may not open all
ungrounded poles and leave the capacitor energized when i t
should be de-energized.
PANEL RECOMMENDATION: Accept as Revised:
I Change(2) to read: "The disconnecting means shall open all
ungrounded conductors simultaneously." The rest of the Code
remains the same.
VOTE ON PANELRECOI~ENDATION: UnanimouslyAffirmative.
ARTICLE 470 -- RESISTORSAND REACTORS
CMP 13
470, Part A: Reject
SUBMITTER: TSC-Nominal Voltage
PROPOSAL: 40 Revise the t i t l e as Follows:,
~ 0 0
Volts, Nominal, or Less
SUBSTANTIATION: To obtain uniformity of voltage levels and
ratings throughout the Code.
PANEL RECO~ENDATION: Reject.
PANEL COMMENT: The present wording adequately reflects the
Panel's intent.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 710 -- OVER600 VOLTS, NOMINALGENERAL
710-2: Reject
CFP 13
SUBMITTER: H.K. Glenn, Pacific Coast Electrical Assn.
~ 4 1
Revise as follows:
Provisions applicable to specific types of installation are
included in Section 710-2 interrupting rating and. . . .
SUBSTANTIATION: The Pacific Coast Electrical Association has ,
~~p-roposal
to Panel No. I Section 110-9 proposing that
closing and momentary ratings be added to that section to cover
all devices that interrupt current at fault levels. We believe
that interrupting rating should be covered in one place only,
namely Section 110-9. See Pacific Coast Electrical Assn.
proposal for Section 710-21.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not agree with the supporting
comment.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
710-I: Accept
CMP 13
SUBMITTER: C~ 13
I
~
41A Add the word "nominal" after 600 volts. .
~'I]I~'FA}[TIATION: To'comply with the Technical Subcem~nittee's
recommendations on nominal voltage.
PANEL RECOMMENDATION: Accept.
VOTEON PANELRECOMMENDATION: UnanimouslyAffirmative.
CMP 13
710-2: Accept
SUBMITTER: TSC - Skin Effect Current Tracing
P-h--O-P~-~A~-~-.'42 Add "Article 427, Fixed Electric Heating
~ t
for Pipelines and Vessels."
SUBSTANTIATION: To correlate with proposed revisions for
Article 427.
PANEL RECOI~ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
l
710-2: Accept
C~ 13
SUBMITTER: C~ 13
I~TO-h-O-S~A-CT.4
' 2A Add "Article 364, Busways" to Article 710-2 after
X-~'T'c~-'347, Rigid Nonmetallic Conduit.
SUBSTANTIATION: To be consistent with panel action on Proposal
No. 44.
PANEL RECOI~ENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
460-B(c)(1),(2),and(3):
Accept
C~ 13
SUBMITTER: Stanley K. Hall, Duquesne Light Company
]~-OII~'TAt-~.
• 39 Revise as follows:
-~isconnecting
Means.
(I) A disconnecting means shall be provided in each
ungrounded conductor to simultaneously open all ungrounded
conductors for each capacitor bank.
(2) The disconnecting means shall be permitted to
disconnect the capacitor from the line as a regular operating
procedure.
(3) The rating of the disconnecting means shall not be less
than 135 percent of the rated current of the capacitor.
SUBSTANTIATION: This proposal will eliminate single pole
switching of low voltage capacitors. This practice is already
obsolete and not in general use. This is already a requirement
for capacitors over 600 volts. Art. 460-24 (a).
710-3(a) and (b): Accept
CMP 13
SUBMITTER: H. F. van der Voort, Cleveland, OH
l~J~rO-F~B~-~." 43 Add the words "in rigid nonmetallic conduit u t o
the f i r s t sentence, paragraph "(a) Aboveground Conductors" after
"in intermediate metal conduit" and before "in cable trays."
In paragraph "(b) Underground Conductors," amend the last
sentence before Table 710-3(b) b~ deleting the words "encased in
not less than 3 inches of concrete."
SUBSTANTIATION: Schedule40 rigid PVC conduit is suitable in
applications where the potential exceeds 600 volts. High
voltage, high current short circuit tests were conducted on 4
inch Schedule 40 Rigid PVC Conduit under a wide •range of
conditions. The results prove that the conduit exhibits l i t t l e
or no signs of deterioration or physical damage due to the
explosions and high temperatures. The report of the results of
218
\
REPORT OF CODE-MAKINGPANEL NO. 22
ARTICLE445 -- GENERATORS
445-I: Reject
CMP 22
SUBMITTER: IdahoChapter IAEI
]5~-Ob
l -O-SA
' ~-~." 1
AmendSection 445-1 to include Article 240.
~]I~rANTIATION: 240-21 t e l l s us all conductors shall be
protected at point of supply. The inherent design of a
enerator only protects the generator i t s e l f . Nowherein
r t i c l e 445 does i t give any specific overcurrent protection for
the conduEtor leading from the generator.
These generators can be changed in the field to a larger
generator without any knowledge of conductor ~npacity or
overcurrent requirements thereby causing an overload on the
conductors and creating a f i r e hazard. In some installations
the conductors leading from the generator to the f i r s t
overcurrent device is greater than 100 feet.
See Proposal No. 3 for 445-5.
"PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Unduly restricting design for larger units where
other methods to prevent overloading of conductors have shown to
be adequate. Supporting comment is not persuasive. This
article outlines requirements for protection of generators.
Other sections of the NEC cover conductor overcurrent
protection. Modifications of systems must be reviewed
completely for compliance with all rules applicable in the NEC.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: g.
NEGATIVE: Flach.
EXPLANATION OF VOTE:
FLACM: I don't think adding Article 240 to the l i s t of other
Articles will create any controversy. By doing this, Code users
will be alerted to the fact that the inherent design of a
generator does not protect conductors connected to the generator
output terminals.
~
be adequate. Overcurrent protectioh should be as close as
practicle, but 25 feet is too restrictive.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 8.
NEGATIVE: Flach, Scalone.
EXPLANATION OF VOTE:
FLACH: I agree that 25 feet may be too short for large
machines, but there should be some statement in the Article
which requires overcurrent protection for the conductors
connected to the generator.
SCALONE: The installation of an unprotected feeder for great
distances within a building might cause a greater threat to
human l i f e such as f i r e , explosion or electrocution, than would
be caused by the lack of emergency power. I suggest modifying
the proposed wording:
"The length of exposed feeder installed from the generator
terminals to the f i r s t overcurrent protective device shall not
exceed 25 feet."
445-6: Accept
CMP 22
SUBMITTER: TSC-Nominal Voltage
I~TOIR)~L-~.4 Change"generators of more than 150 volts to
grou-~-u-6~--to read "generators operated at more than 150 volts t o
iground.,
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 480
STORAGEBATTERIES
480-5(b):Accept
CMP 22
SUBMITTER: TSC-Nominal Voltage
I~ROIoI)~3~-~.
• 5
Add "nominal" after "24 volts" to read "(24
vo-'61"t-~7-5,
nominal)."
SUBSTANTIATION: To conform to the guidelines established by the i
TSC on Nominal Voltages.
PANEL RECOI~MENDATION: Accept
VOTE ON PANELRECOMMENDATION: Unanimously AffirmatiVe.
445-5: Reject
CMP 22
SUBMITTER: GeorgeW. Flach, New Orleans, LA
2
Reviseby adding "and neutral" after "phase
~ r s . "
The sentence will then read: "The ampacity of the
phase conductors and neutral from the generator terminals to the
f i r s t overcurrent device shall not be less than 115 percent of
the nameplate current:rating of the generator.
SUBSTANTIATION: Clarification.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: CMP agrees with the intent of the Proposal see
actlon on Proposal No. 2A, Section 445-5.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 700 -- EMERGENCYSYSTEMS
Article 700: Reject
CMP 22
SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn.
]~-OPO~'-A-L-~.'6 CemblneArticles 700 and 750.
~'I]I)'S'TA)~TIATION: Adopt the report of CMP TSC to combine Articles
700 and 750r Complete text as shown on pages 391, 392, 393, 394
of the "Preprint of the proposed amendments for the 1978
National Electrical Code." NFPANO. 70 PR 78.
The present separation of the articles, both of which deal
with alternate power sources and distribution systems intended
to be functional when normal power supplies are disrupted, is
illogical and is a source of conflict in application and
enforcement.
The TSC report was well conceived and the integrated subject
matter provides a much more coherent coverage of alternate Power
Systems. The supporting comment by CMP 22 which accompanied the
proposal thoroughly covers the subject and is s t i l l pertinent.
The Correlating Co¢mnittee (see Secretary's note) apparently
agreed with the developed material, but unfortunately the
assignment to "process new material in the appropriate articles"
was not accemplished. Such action to pull apart the work of the
TSC would be ill-advised and would destroy the logical
arrangement.
PANEL RECOMMENDATION: Reject
PANEL COMMENT: See CMP action on Proposal No. 7. The
Correlatlng ~emmittee has instructed CMP 22 to keep the articles
separate.
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
COW,lENT ON VOFE:
FLACH: Separating this proposal as has been done in Proposal
NOS. 21A through 21S should reduce this confusion between
requirements for emergency, legally required stand-by, and
optional stand-by systems.
445-5: Accept
CMP 22
SUBMITTER: CMP 22
I~TOITO-S)'~-~
". 2A
Add a sentence to the end of 445-5 as follows:
be permitted t o size the neutral conductors in
accordance with Section 220-22.
SUBSTANTIATION: To clarify requirements for sizing the neutral.
To be consistent in sizing the neutral with other sources and
distribution methods.
PANEL RECOMMENDATION: Accept as revised. I t shall be permitted
to slze the neutral conductors in accordance with Section
220-22. Conductors which must carry ground-fault currents shall
not be smaller than required by Section 250-23(b).
PANEL COII~ENT: Where the generator neutral is not grounded at
Its terminal, the neutral cohductor must be of adequate size to
carry ground-fault current.
VOTE ON PANELRECO~B~ENDATION: UnanimouslyAffirmative.
445-5: Reject
CMP 22
SUBMITTER: IdahoChapter IAEI
3
Amend445-5 by adding another sentence stating
~ductor
shall not be over 25 feet in length and shall
terminate with a single circuit breaker or a single set of fuses
that will limit the load to the ampacity of the conductors."
SUBSTANTIATION: 250-5(d) states that generators are a
separately derived system. I f they are such we should have some
rules for giving the conductors from the generator proper
protection. There are times when i t is hard to install an
overcurrent device at the generator location. I f we used a 25
foot tap rule from the generator to the overcurrent device i t
would prevent installations of great distance from the generator
to the overcurrent device.
240-21 tells us all conductors shall be protected at point of
supply. The inherent design of a generator only protects the
generator i t s e l f . Nowherein Article 445 does i t give any
specific overcurrent protection for the conductor leading from
the generator.
See Proposal No. 1 for 445-I.
PANEL RECOMMENDATION: Reject
PANEL COMMENT: Unduly restricting design for larger units where,
other methods to prevent overloading of conductors have shown to
- -
Article 700 and 750-(New)(HOD 1978 NEC): Reject
CMP 22
SUBMITTER: CMP 22
RTOIO~3XLr•~. 7
Reportof CMP TSC to combine Articles 700 and 750
ARTICLE 700
ALTERNATE POWERSYSTEMS
A. General
' 700-1. Scope. The provisions of this article apply to the
installation, operation, and maintenance of systems consisting
of circuits and equipment intended to distribute and control
electricity for illumination and/or power when the normal supply
or system is interrupted. Unless specifically referenced, these
provisions do not apply to health care f a c i l i t i e s which are
covered by Article 517.
j
700-2. An alternate power system shall be classified as one of
the following:
332
-
1
i t has an e l e c t r i c a l r e s i s t i v i t y equal to or less that 102
ohm-cm.
Group F - that a dust be classified e l e c t r i c a l l y ,
semi-conductive i f i t has an electrical r e s i s t i v i t y equal to'or
less than 108 ohm-cm, but greater than 102 ohm-cm.
Group G - that a dust be classified electrlcally
non-conductive i f i t has an electrical r e s i s t i v i t y greater than
ARTICLE 500 -- HAZARDOUS (CLASSIFIED) LOCATIONS
500-1: Accept
CMP 14
SUBMITTER: CMP 14
PROPOSAL: IA Add the following at end of fine print note
~ g
to NFPA No. 493: and Installation of I n t r i n s i c a l l y
Safe Instrument Systems in Class I Hazardous Locations ANSI/ISA
RP 12.6-1976.
\
SUBSTANTIATION: No reference or informatlon on installation
requirements for i n t r i n s i c a l l y safe systems. ANSI/ISA RP 12.6
is such a Standard.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
~U~L KtcOMMENOATION: Accept as Revised:'
In Group P, remove the words "or any similar dust" and replace
with the word "and." Add to the definition of Group F: " . . . b u t
equal to or less than 108ohm-cm.. Add the words "or
combustible" to Group G before the word "plastics" and remove
the comma after "plastics."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Adams, Magison.
COMMENTON VOTE:
EWERS: I would like to point out a problem that •arises with
this classification. Coal and coke dust is now classified as
Group F. However, with this proposal coal dust may be in Group
F or in Group G depending on moisture content.
SHORT: This proposal clarifies the classification of dusts.
My concern js that there is no reference table that gives the
r e s i s t i v i t y of dusts which is readily available to the user.
EXPLANATION OF VOTE:
ADAMS: I believe that by adding a highly technical
specification for grouping dusts, even in a fine print note, the
true explosive potential of the materials are lost. The
grouping in this proposa! is questionable and to make this
change at this time, with almost sure revision in the next Code,
would be a mistake.
MAGISON: Proposal No. 3 provides quantitative definitions of
Groups E, F and G, and is therefore a significant improvement
over the language of the 1978 NEC. However, Proposal No. 5 is a
mere significant improvement in that i t clearly distinguishes
between conductive dusts and nonconductive dusts, and is
therefore in accord with Proposal No. 18 as modified by the
Panel.
500-1: Accept
CMP 14
Secretary's Note: I t was the action of the Correlating
Committee that further consideration be given to the comments
expressed in the voting.
SUBMITTER: CMP 14
PROPOSAL: IB In f i r s t paragraph add: "due to flammable
vapors, combustible dust, or ignitible fiber~ or flyings."
SUBSTANTIATION: The existing statement in the f i r s t paragraph
is not complete. The only f i r e and explosion hazards covered by
Articles 500-503 are due to flammable vapors, combustible dust,
or ignitible fibers or flyings. See 510-1 for similar statement
for Articles 511 through 517.
I PANEL RECOMMENDATION: Accept as Revised:
Add the words "gases or" after "flammable" in Proposal.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 17.
NEGATIVE: Conaway.
EXPLANATION OF VOTE:
CONAWAY: I have voted negative as I belie@e that the proposal
should be changed to include flammable liquids. Liquids are
mentioned in paragraph 2.
The proposal should read: "Due to flan~nable vapors or
liquids, combustible dust, or ignitable fibers or flyings."
500-1, FPN: Accept
CMP 14
SUBMITTER: Howard P. Kempsell, Chairman of NFPA Sectional
on Chemistry Laboratories
PROPOSAL: 2
Add new paragraph to fine print note as follows:
]~o-r-eTe~trical classification of laboratory areas, see Standard
for Fire Protection of Laboratories Using Chemicals NFPA45-1975.
SUBSTANTIATION: Chemistry Laboratories have traditionally been
considered non-hazardous (non- classified) areas, as far as
electrical equipment is concerned. This recognizes the
relatively small quantities of flammable liquid that might be
involved in a spill and the presence of other more obvious
sources of ignition, such as hot plates or bunsen burners (both
of which are indispensable laboratory equipment).
PANEL RECOMMENDATION: Accept as Revised:
Add reference to NFPA 45-1975 to l i s t on page i48 of the NEC.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
500-2: Accept
CMP 14
SUBMITTER: E. C. Magison, Honeywell Inc.
PROPOSAL: 3
Revisedefinitions of Groups E, F, and G as
Group E: . . . s i m i l a r l y hazardous characteristics having
r e s i s t i v i t y of 102 ohm-cm or less.
Group F: ...explosion hazard, or any similar dust having
r e s i s t i v i t y greater than 102 ohm-cm but less than lOB ohm-cm.
Group G: . . . f l o u r , starch, grain, plastics, or chemical dusts
having r e s i s t i v i t y greater than 108 ohm-cm.
SUBSTANTIATION: This recommendation moves the National
Electrical Code toward a more definitive classification of
dusts. The prevalence of dust in industrial processes ( i . e . ,
plastic dust, wood dust, etc., which are not presently
classified by the Code) dictates a more precise classification
based on reliable scientific criteria that will aid users of the
National Electrical Code.
The National Academy of Sciences (NAS), under contract by the
Occupational Safety and Health Administration, set up a Dust
Test Equipment Panel, staffed by prominent experts who studied
the various methods used for testing the characteristics of
dusts. An objective of this study is to be better able to
classify the various dusts according to the Groups E, F, and G
for hazardous locations, as presently described in the NEC. The
test procedure for evaluating the r e s i s t i v i t y of dust used was
the hotplate method being proposed as the International
Electrotechnical Cofmnission test method by Working Group No. 2
of Subcommittee 31H. Details of the method are explained in
the attached report.*
*Attached report has been supplied to CMP.
The i n i t i a l study ~ndicated that the present Groups E, F, and
G in Article 500 of the NEC were classified according to:
Ignition temperature of the dusts, and electrical conductivity
of the dusts (page 2 of the report).
In analyzing various methods pertaining to the electrical
r e s i s t i v i t y of dusts, one important conclusion of the study
would better define the r e s i s t i v i t y of dusts within the Groups.
Group E - that a dust be classified electrically conductive i f
500-2: Accept
CMP 14
SUBMITTER: CMP 14
3A Reword third fine print note to read:
~urposes
of testing, approval, and area classification
various air mixtures . . . . "
• SUBSTANTIATION: For clarification.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
500-2: Accept
CMP 14
SUBMITTER: Idaho Chapter IAEI
4
In Section 500-2(a) second line, delete the word
~ o n "
and replace i t with the words "explosive,
combustible or i g n i t i b l e . " In the third line delete the word
"or," place a comma after the word "dust," and add "fiber or
flyings." In the f i f t h line delete the word "or," delete the
period after the word "dust" and add a comma and add the words
"fiber or flyings."
The f i r s t paragraph of Section 500-2(a) would then read:
"Equipment shall be approved not only for the class of
location but also for the explosive, combustible, or ignitible
properties of the specific gas, vapor, dust, fiber or flyings
that. will be present. In addition, equipment shall not have
exposed any surface that operates at a temperature in "excess of
the ignition temperature of the specific gas, vapor, dust,
fiber, or flyings."
SUBSTANTIATION: Class I l l locations have an approval for class
propertles as well as Class I and Class I I locations. The
properties-(fiber and flyings) of ignitibles in Class I l l
locations have been l e f t out of the wording in this section and
should not be excluded. The addition of the words "explosive,
combustible, or ignitible" is the wording used in Section 500-4,
500-5 and 500-6 to describe the properties in Class I, Class I I
and Class I l l locations.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
/
I
500-2: Reject
CMP 14
SUBMITTER: Ernest C. Magison, Honeywell, Inc.
~
5
Changedefinition to read:
~ E :
Atmospheres containing metallic dusts or conductive
carbonaceous dusts which have more than 8 percent total volatile
material (Carbon black per ASTMD1620, charcoal, coal and coke
dusts per ASTMD27~). Conductive dusts are those whose
r e s i s t i v i t y is equal to or less than 105 ohm-centimeters.
Delete Group F definition.
SUBSTANTIATION: This proposal is aimed at providing a
quantitative definition of conductive dusts and simplifying
Class I I requirements. There is in practice l i t t l e use made of
the destinction between Group E (metallic) and Group F
(carbonaceous) dusts. The distinction is between conductive (E
and F) and non-conductive (G) dusts.
The proposed dividing line of 105 ohm-centimeters is based
225
on values presented in ISA SP12.10, Area Classification of
Hazardous Dust Locations, 1973 and studies conducted by the
National Research Council Committee on Evaluation of Industrial
Hazards during the past two years.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Reject in deference to Proposal No. 3.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 17.
NEGATIVE: Magison.
,
COMMENTON VOTE:
ADAMS: My affirmative vote to reject this proposal is for
much the same reason as Proposal No. 3 and illustrates the
possi61e conflicts.
EXPLANATION OF VOTE:
MAGISON: This proposal is in accord with Proposal No. 18 as
modified by the Panel. I believe that no significant confusion
will result from elimination of Group F. Apparatus approved for
Group F only is almost certainly intended primarily for use in
the presence of coal dusts which would be Group G under the
proposed definition. The disposition of apparatus presently
approved for Group F, but not for Group E, could be covered by a
new paragraph in 500-2(a):
"Equipment approved for Group F, but not Group E, in
accordance with earlier editions of this Code, shall not be used
in Group E locations i f the hazard is due to metallic dusts.
Such equipment may be used in Group E locations where the hazard
is due to carbonacious dusts."
Table 500-2(a) Dusts by Groups
Group E Atmospheres
Metals:
Aluminum, atomized collector fines
Aluminum, Flake, A 422 extra fine lining, polished
Boron, amorphous, commercial (85% B)
Iron, hydrogen reduced (98% Fe)
Iron, carbonyl (99% Fe)
Magnesium, milled, Grade B
Thorium (contains 1.2% 02)
Thorium hydride (contains 0.94% H2)
Tin atomized (96%~Sn, 2% Pb)
Titanium (99~ Ti)
Titanium hydride (95% Ti, 3.8% H2)
Uranium
Uranium hydride
Vanadium (86.4% V)
Zirconium, prepared from hydride (contains 0.-3% 02)
Zirconium, hydride (93.6% Zr. 2.1% H)
Alloys and Compounds:
Aluminum-lithium alloy (15% Li)
Aluminum-manganese alloy (Do~m~etal) '
Aluminum-silicon alloy (12% Si) .
Group F Atmospheres
Carbonaceous" Dusts:
Charcoal, hardwood mixture
Gilsonite, Utah
Pitch, coal tar
sphalt, blown petroleum resin
itch, petroleum
Coal, Kentucky (Bituminous)
Coal, Pennsylvania, Pittsburg (Experimental Mine Coal)
Lignite, California.
500-2, FPN: Reject
CMP 14
SUBMITTER: Douglas R. Pratt, Dow Corning Corp.
6
Revisefine print note as follows:
r ~ p G: Atmospherescontaining flour, starch, grain, o r ,
other dusts with similar characteristics.
SUBSTANTIATION: Recently we have been involved in t h e
classification of production f a c i l i t i e s in which combustible
elemental silicon is present in a dust form. Dust particle size
ranges from 1 to 90 microns, with the bulk of samples at
approximately 35 microns.
Difficulty was encountered with the application of Section
500-2, describing the various "Groups" of hazardous dust
materials. In an effort to determine the particular "Group"
into which elemental silicon would f a l l , we turned to
definitions developed by the Instrument Society of America,
Standard S 12.10, dated 10/73, basing classifications upon
conductivities of dusts in controlled conditions.
I t was discovered, as a result of tests performed by Hazards
Research Corp., that combustible elemental silicone described
above, behaves similar to agricultural, plastic and other
"non-conductive" dusts, lying well within "Group G."
We would also like to encourage the adoption of the ISA
Standard 12.10, or the development of a similar standard, to
assist institutions in correctly classifying their f a c i l i t i e s by
better defining the National Electrical Code's Class I I Groups.
PANEL RECOMMENDATION: Reject
PANEL COMMENT: Reject in deference to Proposal No. 3.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 17.
NEGATIVE: Adams.
EXPLANATION OF VOTE:
ADAMS: I think this proposal should be accepted, modified to
read: " . . . o r other dusts with similar hazardous
characteristics."
~
Group G Atmospheres
Agricultural Dusts:
Almond shell
Apricot pit
Cellulose
Cellulose, alpha
Cellulose, flock, fine cut
Cherry pit
Cinnamon
Citrus peel
Coca bean shell
Cocoa, natural 19% fat
Coconut shell
Coffee, f u l l roasted
Corn
Corncob g r i t
Corn, dextrine pure
Cornstarch commercial product
Cornstarch (thru No. 325 Sieve)
Cork dust
Cottonseed meal
Cube root, South American
Flax shive
Garlic, dehydrated
Grain dust, winter wheat, corn, oats
Guar seed
Gum, arabic
Gum, karaya
Gum, Manila (copal)
Gum, tragacanth
Hemp hurd
Lycopodium
Malt barley i
Milk, skimmed
Pea flour
Peach pit shell
Peanut hull
Peat, sphagnum, sun dried
Pecan nut shell
Pectin (from ground dried apple pulp)
Potato starch, dextrinated
Pyrethrum, ground flower leaves
Rauwolfia vomitoria root
Rice
Rice bran
Rice hull
Safflower meal
Soy flour
Soy protein
Sucrose, chemically pure
Sucrose
Sugar, powdered
Tung kernels, oil free
Walnut shell, black
-Wheat, untreated
Wheat flour
Wheat gluten, gum
Wheat starch, edible
Wheat starch, allyl chloride treated
Wheat straw
500-2 FPN: Accept
CMP 14
Secretary's No~e: I t was the action of the Correlating
Committee that the Panel make editorial adjustment to make the
fine print note a sentence.
SUBMITTER: E. C. Magison, Honeywell Inc.
7
In the fourth paragraph after reference to Table
~ d :
For groups E, F and G see Table 500-2(c). And add
now Table 500-2(c) to include the dusts.now listed in the Fire
Protection Handbook, classified as indicated.
SUBSTANTIATION: I t is recommended that the various dusts listed
in the National Fire Protection Association's Fire Protection
Handbook, 14th Edition, pages 3-107 through 3-114 be included in
the National Electrical Code. The National Academyof Sciences
under contract by the Occupational Safety and Health
Administration has classified the dusts within the scope Groups
E, F, and G in the Code as well as by the data concerning dust
resistivity (another recommendation).
There is a need for a more definitive dust classification
within the National Electrical Code. The prevalence of dusts in
industrial processes ( i . e . , plastic dust, wood dust, etc., which
are presently not classified) dictates a more precise
classification based on reliable scientific c r i t e r i a and
information. This listing would f a c i l i t a t e easier referencing
and better application of the National Electrical Code. I t is
therefore recommended that these dusts be included in the
National Electrical Code as classified in the attached listing.*
*Attached listing supplied to CMP ~:mbers.
I PANELRECOMMENDATION: Accept as revised:
~th-e-f-ou-rt-h p-a~-agraph after reference to Table 500-2 add:
"For Groups E, F and G, see Table 500-2(a)." Add now Table
500-2(a) as follows:
226
Wood, birch bark ground
Wood flour, white pine
Yeast, torula
Acrylonitrile-vinyl chloride-vinylidene chloride
Acrylonitrile-vinyl chloride-vinylidene chloride copolymer
(70-20-I0)
Chemicals:
Acetoacetanilide •
Acetoacet-o-toluidine (2 methylacetoacetanilide)
Acetoacet-p~phenetidide
Adipic acid
Anthranilic acid
Aryl nltroso methyl amide
Azelaic acid
a.a' Azoisobutyronitrile
Benzoic acid
Benzotriazole
Bis-phenol A
I
o-Chloroacetoacetanilide
)-Chloroacetoacetanilide
Dehydroacetic acid
Diallyl phthalate
Dicumyl peroxide suspended on CaCO3 (40-60)
Dicyclopenladiene dioxide
Dimethyl isophthalate
3, 5 dinitrobenzoic acid
Dinitrotoluamide (35 dinitro ortho toluamide)
Diphenyl
Ditertiary butyl para cresol
Ethyl hydroxyethyl cellulose
Fumaric acid
Hexamethylene tetramine
Hydroxethyl cellulose
Isatoic anhydride
DL-Methionine
Nitrosoamine
Para oxy benzaldehyde
Para phenylene diamine (milled)'
Para tertiary butyl benzoic acid
Pentaerythritol
Phenyl beta naphthylamine
Phthalic anhydride
Phthalimide
Salicylanilide
Sorbic acid
Stearic acid, aluminum salt (aluminum tristearate
Stearic acid, zinc salt (zinc stearate)
Sulfur
Terephthalic acid
Group I l l , Cellulosic Resins
Cellulose acetate
Cellulose triacetate
Cellulose acetate butyrate
Cellulose propionate, 0.3% free' hydroxyl
Ethyl cellulose 5-10 micron dust
Methyl cellulose
Carboxy methyl cellulose, low viscosity, 0.3 to 0.4%
substitution, acid product
Hydroxyethyl cellulose-mono sodium phosphate sizing compound
Group IV. Chlorinated Polyether Resins
Chlorinated polyether alcohol
Group VI. Nylon (Polyamide Resins)
Nylon (polyhexamethyleneadipamide) polyme~
Group VII. PolycarbOnateResins
!Polycarbonate
o
Group VIII. Polyethylene Resins
Polyethylene, hl-pressure process
Polyethylene, low-pressure process
Polyethylene wax, low molecular weight
Group X. Polypropylene Resins
Polypropylene (contains no antioxidant)
Group XI. Rayon
Rayon (viscose) flock, 1.5 denier, 0.020 inch maroon
Group XII. Styrene Polymer and Copolymer Resins
Polystyrene molding compound
Polystyrene latex, spray-dried, contains surfactants
Styrene-acrylonitrile copolymer (70-30)
Styrene-butadiene latex copolymer, over 75% styrene, alum
coagulated
Group XIII. Vinyl Polymer and Copolymer Resins
Polyvinyl acetate
Polyvinyl acetate alcohol
Polyvinyl butyral
Vinyl chloride-acrylonitrile cSpolymer, water emulsion
~ product (60-40)
Vinyl chloride-acrylonitrile copolymer, water emulsion product
(33-67)
Polyvinyl-chloride-dloctyl phthalate mixture (67-33)
Vinyl toluene-acrylonitrile-butadiene copolymer (58719-23)
Drugs:
2-Acetylamino-5-nitcothiazole, NHCOCH
3 1 S-C=N-CH=C-NO2
2-Amino-S-nltrotheazole, NH2 S-C:N-CH:C-NOo
Aspirin (Acetylsalicyclic Acid o-CH3cooc6H~cooH
Gulosonic acid, diacetone C1~H1,rm~n
Mannitol (hesahydric alcohol) CH~
2 c~(CHOH)4CH2OH'
Nitropyridone
L-Sorbose
(CIoH1104N3)
Thermosetting Resins and Molding Compounds:
Group I. Alkyd Resins
Alkyd molding compound, mineral f i l l e r , not self-extinguishing
Vitamin BI, menonitrate. ~12H170N4SN03
Vitamin C, ascorbic acla u6~806
Group II. Allyl Resins
A l l y l alcohol derivative CR-39, (from dust collector)
Dyes, Pigments and Intermediates:
I, 4-Diamino-2, 3-dihydroanthraquinone (90%) I
methylamino-anthraquinone (10%) (Violet 200 dye)
I, 4-Di'-p-toluidineanthra-quinone (70%), B
naphthalene-azo-dimethyl-aniline (30%) (green base harmon dye)
1-Methyla~inoanthraquinone (red dye intermediate)
B-naphthalene-azo-dimethylaniline
Group I l l . Amino Resins (Melamine and Urea)
Urea formaldehyde molding cempound, Grade I I , fine
• Urea formaldehyde-phenol formal-dehyde molding
compound, wood flour f i l l e r
Group VI. EpoxyResins
Epoxy, no catalyst, modifier~or additives
Epoxy-bisphenol A mixture
Alloys and Compounds:
Calcium s i l i c i d e
Ferromanganese~ medium carbon
Ferrotitanium (19% Ti, 74.1% Fe, 0.~6%C)
Group V. Furane Resins
Phenol furfural
Pesticides:
Benzethonium Chloride
Bis (2-hydroxy-5~chlorophenyl) methane
Dleldrin (~2H80~I~ 20% (50% Combustible 30% inert)
2,6 Di-terzlary-ou~#l-paracresom
Ferric dimethyldithiocarbamate (Ferbam).
Manganese vanicde ((CH31~ NC(~I~ ~M1Naphthyl-N-methylcar6A~a~e'{"~e~)nW) 15% (85% inert)
3, 4, 5, 6 tetrahydro-3, 5-dimethyl-2H-1, 3, 5 thiadeazine
2 thione, ("Craig" No. 974) 5% (95% inert)
a, a' Trithiobis (N, N-dimethyl-thioformamide)
'.
Group VI. Phenolic Resins
Phenol formaldehyde
Phenol formaldehyde, l-step
Phenol Tormaldehyde, 2-step
Phenol formaldehyde molding compound, wood flour f i l l e r
Phenol formaldehyde, polyalkylene polyamine modified
Group VII. Polyester Resins
Polyethylene terephthalate
Styrene modified polyester-glass fiber mixture (65-35)
Thermoplastic Resins and Molding Compounds:
Group VIII. Polyurethane Resins (Isocyanate)
Polyurethane foam (toluene diiso-cyanate-polyhydroxy
with fluorocarbon blowing agent), not fire retardant
Polyurethane foam (toluene diiso-cyanate-polyhydroxy
with fluorocarbon blowing agent),'fire retardant
Group I. Acetal Resins
Acetal, linear (Polyformaldehyde)
Group.II. Acrylic Resins
Methyl methacrylate polymer.
Methyl methacrylate-ethyl acrylate copolymer
Methyl methacrylate-ethyl acrylate-styrene copolymer
Methyl methacrylate-styrene-butadiene-acrylonitrile copolymer
Methacrylic acid polymer, modified
Acrylamide polymer
Acrylonitr.ile polymer
Acrylonitrile-vinyl pyridine copolymer
Special Resins and Molding Compounds:
Group I. Cold Molded Resins
Petroleum resin (blown asphalt, regular)
Group If. Coumarone-lndeneResins
Coumarone-lndene, hard
227
Group I l l .
Natural Resins
Cashew o i l phenolic, hard
Lignin, hydrolized-wood-type, fines
Rosin, DK
Shellac
Soldium resinate, dry size grade XXX
PANEL COMMENT: See Panel Comment on Proposal No. 7.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 17.
NEGATIVE: Adams.
COMMENTON VOTE:
MILLER: Although I am voting in the affirmative, I believe
more c l a r i f i c a t i o n is needed on the handling of flammable
liquids versus combustible liquids as defined in NFPA 321.
EXPLANATION OF VOTE:
ADAMS: Although these 6 chemical compounds have been tested
and f i t very well into Table 500-2, I think that the additions
w i l l continue to the point of swamping the NEC with handbook
type material.
Group VI. Rubber
Rubber, crude, hard
Rubber, synthetic,.hard, contains" 33% sulfur
Group V. Miscellaneous Resins
Alkyl ketone dimer sizing compound, dimer dispersed on s i l i c a
(50-50)
Chlorinated phenol (bis 2-hydroxy-5 chlorophenyl methane)
Ethylene oxide polymer
Ethylene-maleic anhydride copolymer
Styrene-maleic anhydride copolymer
Petrin acrylate monomer, crude
Add a fine print note at the end of Table 500-2(a) as follows:
"Atmospheres containing charcoal, coal or coke dusts which
have more than 8 percent total v o l a t i l e material ,(ASTM D271) or
atmospheres containing these dusts sensitized by other materials
so that they present an explosion hazard:"
PANEL COMMENT: I t is the Panel's view that i t is inappropriate
to expand the tables of classified materials in the'NEC. The
number of hazardous gases, vapors and dusts is so great that the
classifications should be given in another NFPA publication.
Such a publication would also benefit the user because i t could
also explain the basis f o r the c l a s s i f i c a t i o n scheme. The Panel
recommends strongly that documents such as Report NMAB353-1,
"Matrix of Combustion-Relevant Properties and Classification of
Gases, Vapors and Selected Solids," published by the National
Research Council be used as a basis f o r a new NFPA publication
or a revision of 325M.
However, because the public at present views the NEC as the
source of material classifications, i t is essential that the
l i s t s be included in the 1981NEC.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 15.
NEGATIVE: Adams, Conaway, Ewers.
COMMENTON VOTE:
HALL: Fine print should follow Group F.
MAGISON: I agree with proposal to l i s t additional dusts, but
" believe that the addition of the FPN after the table is
unnecessary because i t duplicates information in the definitions
of the Groups.
MILLER: The fine print note which is part of the Panel
Recommendation needs some e d i t o r i a l ~djustment to make i t into a
sentence.
EXPLANATION OF VOTE:
ADAMS: I believe that this proposal should be rejected. The
extensive table of dusts is something that should be in a
handbook and not in the NEC. I do not believe in putting
material in the NEC temporarily.
CONAWAY: The table material was not available prior to-the
May'1979, meeting so material could not be studied prior to the
meeting.
Great long l i s t s of dust by catagory do not belong in the
Code. Where w i l l the l i s t stop. Proposed l i s t just scratches
the surface of materials that could be listed.
By l i s t i n g certain materials, do we infer that anything'not
listed is nonhazardous.
For certain resins and molding cempounds, there is a breakdown
by Group I - - XII, etc. There is nd explanation of what these
are.
EWERS: Inclusion of a l l the materials listed is too
r e s t r i c t i v e in many cases. I t would unnecessarily c l a s s i f y many
locations that are not a f i r e or explosion hazard.
Table 500-2: Accept
CMP 14
SUBMITTER: E. C. Magison, Honeywell Inc.
8
Add the following materials in the groups
~ d :
Arsine - B
Propyl Nitrate - B
Ethyl Mercaptan Ethyl Sulfide - C
Hydrogen Cyanide - C
Ethylene Glycol Monomethyl Ether - D
SUBSTANTIATION: Under the auspices of the National Academy of
Sciences, the Underwriters Laboratories Inc. has investigated
arsine, ethylene glycol monomethyl ether, ethyl mercaptan,
ethyly sulfide, hydrogen cyanide, and propyl n i t r a t e f o r the
purposes of classifying them within the National Electrical
Code's hazardous locations, Groups A, B, C and D. The results
of the investigation are attached.*
I t is recommended, based on the Underwriters Laboratories
Inc.'s investigation and test results, that these 6 chemicals be
included in the revision of the NEC in the Groups, as designated
in the report.
*Attachments have been supplied to CMP.
PANEL RECOMMENDATION: Accept.
I
,
228
Table 500-2: Accept
CMP 14
SUBMITTER: E. C. Magison, Honeywell Inc.
]~TOI}~FA-L-~.'9
Add the following materials in the Groups
l-6Bl-E~1-6d:
Nonane - D
Cyclohexane - D
Cyclohexene - D
Methylcyclohexane - D
Turpentine - D
Butylene - D
1-Pentene - D
Mexene - D
Heptene - D
Octene - D
Nonene - D
Tripropylene - D
Decene - D
Dipentene.- D
Undecene - D
Tetrapropylene -D
Tridecene - D
,Tetradecene - O
Methylacetylene - C
Ethyl Benzene - D
Curnene - D
Cymene - D r
Tert-butyltoluene - O
Diethylbenzene - D
Styrene - D
a-Methylstyrene - D
Vinyltoluene - D
Liquified petroleumgas - D
Methyl acetylene - Propadiene (MAPP gas)-C
Naphtha, coal tar - D
Naphtha, petroleum - D
Stoddard solvent - D
O-Terphenyl - D
m-Terphenyl - D
p-Terphenyl - D
isopropyl alcohol - O
Hexanol - D
Methyl amyl alcohol - D
Ethyl butanol - D
Methyl isobutyl carbinol - D
Methyl cyclohexanol - D
Diacetone alcohol - D
Propionaldehyde - C
iso-butyraldehyde - C
Valeraldehyde - C
3-methyl butyTaldehyde - C
iso-pentyl aldehyde - C
2-ethylhexaldehyde - C
iso octyl aldehyde - C
2-ethyl-3 propyl-acrolein - C
Glyoxal - C
Glutaraldehyde formic acid - D
Propionic acid - D
Acrylic acid (inhibited) - D
Acetic anhydride - D
Methyl formate - D
Ethyl formate - D
Methyl acetate - D
n-propyl acetate - D
isopropyl acetate - D
n-butylacetate - D
sec-butylacetate - O
Tert-butylacetate - D"
n-amylacetate - D
isoamylacetate - D
sec-amylecetate - D
sec-hexylacetate - D
methyl acrylate - D
n-butyl acrylate (inhibited) - D
iso-butyl acrylate (inhibited) - D
methyl methacrylate -D
o-dimethyl phthalate - 0
Butyl benzyl phthalate-O
Methyl formal - C
propyl formal - C
n-Butylformal - C
iso-butyl formal - C
/J
• Phenyl ether - D
2-hydroxyethyl a c r y l a t e - D
1,4-dioxane (diethylene dioxide) - C
Glycidol - C
Diglycidyl ether - C
Isopropyl glycidyl ether ~ C
Furfural - C
n-Ethyl morpholine - C
Methyl chloride - D
Methylene chloride - D
Ethyl chloride - D
1,1-dichloroethane - D
Methyl chloroform - D
1,1,2 - Trichloroethane - D
1,2,3 Trichloropropane - D
1,2 - dichloroethylene - D
Vinylidene chloride (inhibited) - D
trichloroethylene - D
A l l y l chloride - D
1,3 - Dichloropropene - D
Chloroprene - D
Ethylene chlorohydrin - D
Methyl bromide - D
Ethyl bromide - D
Chlorobenzene - D
p-dichlorobenzene - D
Methyl iodide - D
1,3, dichloro-5,5-dimethyl hydantoin - D
Methylamine - D
Isopropylamine - D
Butylamine - D
Hexamethylamine diamine - D
Diethylaminoethanol - D
Xylldine - D
Anisidine - D
p-phenylene diamine - D
Hydrazine - C
Monomethylhydrazene - C
Nitromethane - C
Nitroethane - C
1
1-Nitropropane - C
p-nitrochlorobenzene - O
p- Nitro aniline - D
Acetonitrile - D
Tetramethyl succinonitrile - D
Methyl isocyanate -D
Propylene imine - C
Hexamethylenimine - C
Dimethyl Acetamide -D
Dimethyl formamide - D
Tetra-ethyl lead - C
Tetra-methyl lead - C
Ethyl s i l i c a t e - D
Dibutylphosphate - D
T r i p h e n y l phosphate - D
Dimethyl 1,2-dibromo-2-2-dichlorethyl phosphate (dibrom) - D
Dimethyl sulfate - D
a l l y l propyl disulfide - C
i
SUBSTANTIATION: This recommendation moves the NEC toward a more
comprehensive and usable standard regarding i t s application to
vapors and gases in hazardous locations. Under contracts with
the U.S Coast Guard (completed) add more recently, the
'
Occupational Safety and Health Ac~ninistration (not completed),
the National Academy of Sciences (NAS) has sought a more
' inclusive c l a s s i f i c a t i o n of gases and vapors, as defined in the
National Electrical Code as Groups A, B, C, and D in hazardous
locations.
The present NEC groupings do not include the many gases and
vapors present in industry today that are capable of
c l a s s i f i c a t i o n through appropriate procedures. The NAS has
undertaken the objective of c l a s s i f i c a t i o n , and although the
document is s t i l l undergoing some review, these recommendations
are proper f o r inclusion in the NEC.
I t is recommended, therefore, that a l l the gases and vapors
indicated above, which are contained in the attached* published
matrix, as well as the draft matrix, noted in the "NAS
Classification" column as either A,.B, C, D, or A, B, C, D, be
added to the l i s t of "gases and vapors in the pr~en~ N~C.- The
remaining gases and vapors marked with an asterisk ( * ) , brackets
( ),. a dagger ( t ) , or a double l e t t e r (X(X), are not
recommended f o r the inclusion at this time.
*Attachments have been supplied to CMP.
PANEL RECOMMENDATION: Accept as Revised:
•
Delete the following from the l i s t :
Tridecene - D
Tetradecene - D
Styrene - D
Naphtha, petroleum - D
O-Terphenyl - D
m-Terphenyl - D
p-Terphenyl - D
Methyl cyclohexanol
2-ethyl 3 propyl-acrolein - C
n-butylacetate
o-dimethyl phthalate - D
xylidine - D
p-phenylene diamine - D
p-nitrochlorobenzene - D
p-Nitro aniline - D
Tetra-ethyl lead - C
Oimethyl sulfate -,D
Add the following to the l i s t :
2LPentanone - D
2-Hexanone - D
2-Heptanone - D
Diisobutyl ketone - D
3-Heptanone - D
Ethyl sec-amyl ketone - D
Cyclohexanone - D
0 methyl syclohetanone - D
dichloroethyl ether - D
PANEL COMMENT: See Panel Comment on Proposal NoL 7.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Adams, Conaway.
'COMMENT ON VOTE:
SCHRAM: My notes show ansidine was also to be deleted.
EXPLANATION OF VOTE:
ADAMS: These 136 chemical compounds should not be included in
Table 500-2. The information belongs in the publication of The
National Academy of Science who developed the l i s t .
CONAWAY: See comments f o r Proposal No. 7. Where does'it a l l
end. What about materials not proposed f o r Table that are
hazardous.
Materials listed in Proposal No. g duplicate items already in
existing Table.
Naphtha Petroleum
Isopropyl Alcohol
Styrene
Petroleum
Naphtha
2 - - Propanol (isopropyl alcohol)
The entire l i s t needs further review.
The l i s t i n g of stoddard solvent is questioned.
I f the l i s t is added, some logical manner of l i s t i n g should be
used.
I
Table 500-2: Accept
CMP 14
SUBMITTER: P. J. Schram, Underwriters Laboratories Inc.
~
10
Delete "sec-butyl alcohol" from the second column.
~IATION:
Editorial correction. "Sec-butyl alcohol" is
same material as "2-butanol (secondary butyl alcohol)" in the
second column, second line of Table 500-2. Apparently when
sec-butyl alcohol was added to Table 500-2 in 1978 Edition of
NEC as per Proposal No. 10, fact that 2-butanol (secondary butyl
alcohol) was already in Table 500-2 was overlooked.
PANEL RECOMMENDATION: Accept.
VOTE"ON PANEL RECOMMENDATION: Unanimously Affirmative.
500-2(a): Reject
CMP 14
SUBMITTER: Idaho Chapter IAEI
11
Revise (a) as follows:
~ e n t
shall be approved not only f o r the class of location
but also f o r the "explosive, combustible, or ignitable"
properties of the specific gas, vapor dust, " f i b e r or f l y i n g s " '
that w i l l be present.
In addition, equipment shall not have
exposed any surface that operates at a temperature in excess of
the ignition temperature of the specific gas, vapor, dust,
" f i b e r , or f l y i n g s . "
SUBSTANTIATION: Class I l l locations have an approval f o r class
properties as well as Class I and Class I I locations. The
properties ( f i b e r and f l y i n g s ) of ignitables in Class I l l
locations have been l e f t out of the wording in this section and
should not be excluded. The addition of the words "explosive,
combustible, or ignitable" is the wording used in Section 500-4,
500-5 and 500-6 to describe the properties in Class I , Class I I ,
and Class I l l locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Already covered by Proposal No. 4.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
500-2ia) ,and (b): Accept
CMP 14
SUBMITTER: G. A. Karstens, AmeriCan Feed Manufacturers
~ o n ,
F. Lind~olm, Association of Operative M i l l e r s , J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 12
Revise (a) as follows:
"--Ta~--~pproval f o r Class and Properties. In Class I locations
equipment shall be approved not only f o r the location but also
f o r the explosion properties of the specific gas or vapor. In Class I I or I l l , Division 1 locations equipment shall be
approved f o r .the dust-ignition-proof properties of the
COmbustible oust or easily i g n i t i b l e fibers or f l y i n g fines that
w i l l be present.
Revise (b) as follows:
(b) Marking. In Class I locations approved equipment shall
be marked to show the Class, Group and operating temperature, or
temperature range, based on operation in a 40°C ambient. In
Class I I and I l l , Division 1 l~cations approved equipment shall
be marked to show the Cl#ss, Group and operating temperature, or
temperature range based on operation in a 40°C ambient.
229
SUBSTANTIATION: I t is the understanding of our organizations
that~we do not need labeled equipment in Class I ] and Class I l l
Division 2 locations. As a result we are recommending this
wording to avoid any possible confusion regarding the type of
equipment to be used in Division 1 or ~ locations.
PANEL RECOMMENDATION: , Accept as revised:
Disregard proposed changes to Section 500-2(a) and revise
proposed changes to Section 500-2(b) as follows: No change in
Paragraph I and revise Exception No. 3 to read:
Exception No. 3: Fixed general purpose equipment in Class I
locations other than fixed lighting fixtures which is acceptable
for use in Class I Division 2 locations . . . .
Add an Exception No. 4 as follows:
Exception No~ 4: Fixed dust tight equipment other than fixed
lighting fixtures which are acceptable for use in Class I I
Division 2 and Class I l l locations shall not be required to be
marked with the Class, Group, Division or operating temperature.
PANEL COMMENT: The Panel agrees that some equipment for use in
Class I I Division 2 and Class I l l locations need not be
specifically marked.
VOTE ON PANEL RECOMMENDATION:
AFFIRMATIVE: 17.
NEGATIVE: Miller.
COMMENTON VOTE:
EWERS: In Section (b) I believe the wording "based on
operation in a 40°C ambient" (2 places) should be changed to
"referenced to a 40°C ambient." Thi~ will agree with the Panel
Recommendation in Proposal No. 13.
EXPLANATION OF VOTE:
MILLER: I am of the opinion that the exceptions should'be
worded to indicate that they do not apply to listed equipment.
500-2(b): Accept
,
CMP 14
SUBMITTER: R. Y. Newton, General Electric Co.
13 Revise f i r s t paragraph as follows:
~ e d
equipment shall be marked to show the Class, Group,
and operating temperature or temperature range, based on
operation in a specified ambient temperature range, for which i t
is approved.
SUBSTANTIATION: The present statement regarding ambient
temperature for equipment operation in Hazardous Locations f i r s t
appeared i n t h e 1971 Code when equipment marking of approved
temperature ranges by identification numbers per Jable 500-2b
was adopted. I t appears to+say that the equipment is approved
only i f operating in a 40°C ambient temperature and neither
higher nor lower temperatures. This was the interpretation on
occasion by Underwriters Laboratories.
UL adopted as standard in 1975 that Class I Gp. D & Class I I
Gp. E. F. and G motors approved for 40ec ambient hazardous
locations were suitable for operation in an ambient tamperature
range of-25°C to 40°C. P. J. Schram of UL, who is presently on
Code Panel 14, is familiar with this.
"Operation in a 40°C ambient" can only be an academic
statement and not a realistic statement. In my opinion there is
a need on the part of specifiers, equipment manufacturers,
users, and regulating authorities for a clear statement that
equipment for hazardous locations is approved based on a
specifi'ed ambient temperature range.
PANEL RECOMMENDATION: Accept as Revised:
"Approved equipment shall be marked to show the Class, Group,
and operating temperature, or temperature range referenced to a
40°C ambient."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
500-2(b): Reject
CMP 14
SUBMITTER: Joseph L. Yosafat, General Electric Co.
]~rOl~'~B~--~." 14 + Revise f i r s t paragraph as follows:
Approved equipment shall be marked to show the Class, Group,
maximum temperature and the maximum ambient temperature for
which i t is approved.
SUBSTANTIATION: The present statement regarding ambient
temperature for equipment operation in Hazardous Locations f i r s t
appeared in the 1971 Code when equipment marking of approved
temperature ranges by identification numbers per Table 500c2b
was adopted., I t appears to say that the equipment is approved
only i f operating in a 4O°C ambient temperature and neither
higher nor lower temperatures. This was the interpretation on
occasion by Underwriters Laboratories.
+
A nationally recognized testing laboratory adopted as standard
in 1975 that Class I Gp. D & Class I I Gp. E, F, and G motors
approved for 40°C ~bient hazardous locations were suitable for
operation in an ambient temperature range of -25°C to +40°C.
P.J. Schram, who is presently on Code Panel 14, is familiar wit~
this.
"Operation in a 40°C ambient" can only be an academic
statement and not a realistic statement. There is a need on the
part of specifiers, equipment manufacturers, users, and
regulating authorities for a clear statement of suitable ambient
temperatures for electrical equipment in hazardous locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Committee action on Proposal No. 13.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
500-2(c) and 502-I: Reject
CMP 14
SUBMITTER: E. C. Magison, Honeywell Inc.15
In the f i r s t paragraph of 500-2(c) add:
~ s t s
the temperature marking shall be at least 25°C lower
than the layer ignitiontemperature at the dust to be
encountered. The ignition temperature for which equipment was
formerly approved is given in the Table below: (use Table
502-1). In the fourth paragraph of 502-1 delete Table 502-1 and
reference to i t .
SUBSTANTIATION: The inclusion of plastics dusts and other dusts
in Group G requires that more f l e x i b l i l i t y of selection of
equipment surface temperatures for Class I I equipment be
available.
I f a dust has a low melting point, a low layer ignition
temperature, or exhibits a change in form, such as foaming, the
equipment surface temperature must be appropriately limited.
This temperature may be lower than those now recognized to be
safe for flours, grain dusts, etc.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Already covered by Section 500-2(a).
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
500-4(a)(I): Accept
CMP 14
SUBMITTER: CI~~ 14
15A Revise 500-4ia)(1) to read:
~ n
which hazardous concentrations of flammable gases or
vapors exist under normal operating conditions; or".
SUBSTANTIATION: Panel is of opinion that woFding of 500-4(a)(I)
and 500-5(a)(1) should be of a similar nature.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ADAMS: My notes indicate "hazardous" should be changed to
"ignitable."
EWERS: The word "hazardous" should be changed to "ignitable"
to agree with Proposal No. 1.
SCHRAM: To be consistent with the Panel Recemmendation on
Proposal No. 1, the word "hazardous" preceding "concentrations"
should be changed to "ignitable."
Q
500-5(a)(i): Accept
CMP 14
SUBMITTER: G. A. Karstens, American Feed Manufacturers
~-s-~--Tai-~on, F. Lindholm, Association of Operating Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 16
Revise (1) as follows:
I I , Division 1 location is a location: (1) in which
combustible dust is in the air under normal operating
conditions . . . . "
SUBSTANTIATION: The wording in this particular paragraph has
led to some confusion between the intent of 500-5(a) and
500-5(b). I t is f e l t that by changing this wording there will
be less misunderstanding as to the definition of Class.I],
Division I and Class I f , Division 2 locations.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COGENT ON VOTE:
HALL: I t is noted that a semicolon appears between condition
(1) and condition ( 2 ) . This was considered an editorial change
when P~nel 14 made editorial changes on the 1975 Code. Since i t
is a substantive change, I believe the comma should replace the
semicolon.
500-5(a), FPN: Reject
. CMP 14
SUBMITTER: Douglas R. Pratt, Dow Corning C6rp.
I~TO-P-O-~FAt-~." 17 Add the words "and inorganic" following the word" o r g Y " in the second paragraph.
SUBSTANTIATION: Recently we have been involved in the
classlficatlon of production f a c i l i t i e s in which combustible
elemental.silicon is present in a dust form. Dust particle size
ranges from 1 to 90 microns, with the bulk of samples at
approximateJy 35 microns.
D i f f i c u l t y was encountered with the application of Section
500-2, describing the various "Groups" of hazardous dust
materials.
In an effort to determine the particular "Group"
into which elemental silicon would f a l l , we turned to
definitions developed by the Instrument Society of America,
Standard S 12.~0, dated 10/73, basing classifications upon
conductivities of dusts in controlled conditions.
I t was discovered, as a result of tests performed by Hazards
Research Corp., that combustible elemental silicone described
above, behaves similar to agricultural, plastic and other
"non-conductive" dusts, lying well within "Group G."
We would also like to encourage the adoption of the ISA
Standard 12.10, "or the development of a'similar standard, to
assist institutions in correctly classifying their f a c i l i t i e s by
better defining the National Electrical Code's Class I ] Groups.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 3.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
230
fibers and flyings in sawmills are not mentioned in the second
fine print note paragraph in Section 500-6(a). I t is obvious
that many types of fibers and flyings are not mentioned, but one
as prevalent in many areas as sawdust and woodchips should be
mentioned there.
Change woodworking plants to woodworking locations because
woodworking locations other than woodworking plants present the
same hazards as do the woodworking plants.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 15.
NEGATIVE: Adams, Conaway, Ewers.
EXPLANATION OF VOTE:
ADAMS: I think the addition of sawmills and "sawdust and
woodchips is too far-reaching.
CONAWAY: I am voting negatively on this Proposal since I feel
further revision is needed. The present section lists clothing
manufacturing p!ants. Clothing plants such as shirt factories,
dress factories, suit manufacturers, etc., do not have hazards
needing Class I l l , Division I installations. Basic t e x t i l e
manufacturing f a c i l i t i e s are and should be covered but clothing
manufacturing plants should not be.
EWERS: I believe i t is too restrictive to include all small
woodworking operations in Class I l l , Division I .
500-5(a) and (b): Accept
CMP 14
SUBMITTER: G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operating Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 18 Delete the fine print notes in both of these
paragraphs.
SUBSTANTIATION: The wording as is in the ~ine print notes was
prepared some 25 years ago. There has been l i t t l e or no change
in this wording. Since that particular time, there has been a
great deal of change in the industry's operation, and the
wording as is can be misleading.
PANEL RECOMMENDATION: Acceptas Revised:
I Delete the FPN in Section 500-5(b). Delete f i r s t paragraph of
FPN in Section 500-5(a). Retain the second paragraph and change
next to last sentence to read: "Electrically conductive dusts
are dusts with a r e s i s t i v i t y less than 105 ohm-cm."
VOTE ON PANELRECO~ENDATION:
AFFIRMATIVE: 15.
NEGATIVE: Conaway,Short.
NOT VOTING: Adams.
EXPLANATION OF VOTE:
ADAMS: I am not voting on this Proposal because the proposed
revision would remove Class I I Division 1 locations.
I would
favor the original proposal more.
CONAWAY: I am voting negatively on this proposal.
I could accept the elimination of the f i r s t paragraph of the
FPN for 500-5(a) i f the second paragraph was retained.
I could also accept the elimination of the FPN following
250-5(b) i f i t was not tied to 250-5(a).
SHORT: There Is no justification to accept 105 ohm
centimenters as the cutoff point for conductive dusts. This
proposal would in effect divide Group F into two groups.
500-5(b): Accept
CMP 14
SUBMITTER: G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 19 Revise as follows:
~ s
I I , Division 2 location is a location in which
combustible dust will not normally be in suspension in the air
or will not be likely to be thrown into suspension by the normal
operation of equipment or apparatus in quantities sufficient to
produce explosive or ignitable mixtures, but (I) where spillage
that may occur will be readily removed and where the
accumulation of dusts will not be sufficient to interfere with
the normal operation of electrical equipment or apparatus; or
(2)" where such deposits or accumulations of combustible dust on,
in or in the vicinity of electric equipment might be ignited by
arcs, sparks or burning material from the failure or abnormal
operation of suchequipment.
SUBSTANTIATION: The wording as changed better describes the
condition that exists in present Class I f , Division 2 locations.
PANEL RECOMMENDATION: Accept as Revised:
I Revise 1978 NEC by adding Mter "equipment or apparatus" in
500-5(b)(1) "under normal operating conditions; or."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
CO~ENT ON VOTE:
SHORT: Although i t is recognized that the wording here is a
marked improvement over that presently in the 1978 NEC, further
improvement will be achieved by the following revised wording:
A Class I I , Division 2 Location is a location in which:
(I) Combustible dust will not normally be in suspension in
the air in quantities sufficient to produce explosive or
ignitable mixtures, and dust accumulations are normally
insufficient to interfere with the normal operation of
electrical equipment or other apparatus.
(2) Dust may be in suspension in the air as a result of
infrequent malfunctioning of handling or processing equipment,
and dust accumulations resulting therefrom may be ignitable by
abnormal operation or failure of electrical equipment or other
apparatus.
500-6(a) FPN: Accept
CMP 14
SUBMITTER: Idaho Chapter IAEI
20 In Section 500-6(a) fine print note, in the third
]Tne--o~-the f i r s t paragraph after "clothing manufacturing
plants," add the words "sawmills and other woodworking
locations." The third line would then read: "mills; flax
processing plants; clothing manufacturing plants; sawmills and
other woodworking locations."
In the second paragraph in the last line after the word
"excelsior," add the words "sawdust, woodchips,".' The last line
wo~Id then read: "baled waste kapok, Spanish moss, excelsior,
sawdust, woodchips, and other materials of similar nature."
SUBSTANTIATION: The additional wording is needed to stress the
f i r e hazards existing in sawmill locations from fibers and
flyings. Fibers and flyings from green timber will dehydrate
and carbonize in a short period of time, and, being an organic
material, is highly susceptable to spontaneous ignition. The
wording "woodworking plants" does not give an indication that
sawmills should be included in this class. In the industry,
woodworking plants are generally considered to be those
locations where wood products are finished after the original
milling of the raw timber. Sawdust and woodchips that are
500-6(a) FPN: Reject
CMP 14
SUBMITTER: Idaho Chapter IAEI
PROPOSAL: 21
In the f i r s t paragraph of the fine print note,
delete tne words "woodworking plants" and replace with the words
"sawmills and other woodworking locations."
In the second paragraph, add the words "sawdust, woodchips"
after the word "excelsior."
SUBSTANTIATION: The additional wording is needed to stress the
f i r e hazards existing in sawmill locations from fibers and
flyings. Fibers and flyings from green timber will dehydrate
and carbonize in a short period of time, and, being an organic
material, is highly susceptible to spontaneous ignition. The
wording "woodworking plants" does.not give an indication that
sawmills should be included in this c l a s s . / I n the industry,
woodworking plants are generally considered to be those
locations where wood products are finished.after the original
milling of the raw timber. Sawdust and woodchips that are
fibers and flyings in sawmills are not mentioned in the second.
fine print note paragraph in Section 500-6(a). I t is obvious
that many types of fibers and flyings are not mentioned, but one
as prevalent in many areas as sawdust and woodchips should be
mentioned there.
Change woodworking plants to woodworking locations because
woodworking locations other than woodworking plants present the
same hazards as do the woodworking plants.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: See Panel action on Proposal No. 20, Section
500-6(a).FPN.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
500-7-(NOW): Reject
,
CMP 14
SUBMITTER: R. S. Pinkerton, Los Angeles, CA'
L~R-O]~O~-A-C-~
•. 22 Add ~ now section as follows:
-~-O~[17-[--.Wiring and Equipment Above Hazardous Locations.
(a) All fixed wiring installed in the open space above
hazardous locations shall be in metallic raceways, Type MI cable
or ALS cable. Cellular metal floor raceway may be used only for
supplying ceiling' outlets or extensions to the area below the
floor, but such raceway shall have no connections leading into
or through any hazardous locations above the floor.
(b) Equipment which may produce arcs, sparks or particles of
hot metal, such as lamps, lampholders for fixed lighting,
cutouts, switches, receptacles, charging panels, generators,
motors or other rotating equipment having make-or-break or
sliding contacts shall be of the totally enclosed type or shall
, be provided with suitable guards or screens to prevent the
escape of sparks or hot metal particles.
SUBSTANTIATION: This proposal is intended to correct an
omission in the Code which does not generally recognize and
provide for the hazard of dropping molten metal or hot metal
particle into hazardous vapors when overhead electrical wiring
or equipment above"and out of the hazardous location, develops a
fault. This requirement is found in certain specific locations
but.it should be stated in Article 500 for all hazardous
locations as the danger is the same.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 17.
NEGATIVE: Boylston.
EXPLANATION OF VOTE:
BOYLSTON: Requirements for wiring above all classified
locations is not well understood by those using the NEC. These
requirements should be covered in Article 500 to provide the
needed emphasis.
231
500-7-(New): Reject
CMP 14
SUBMITTER: Southwestern Section IAEI
PROPOSAL: 23 500-7. Wiring and Equipment Above Hazardous
501-4(b), Exception No. 2-(New): Reject
CMP i%
SUBMITTER: James M. Daly, The Okonite Co.
PROPOSAL: 28 Delete last paragraph of 501-4(b). Replace with
a new exception as follows:
Exception No. 2: Where installed in cable tray, Type MV
single conductors and multiconductor cables rated 2001 Volts and
over shall have metallic shielding on each conductor.
Multiconductor Type MC cable with a continuous metallic sheath
shall be permitted to have nonshielded conductors.
SUBSTANTIATION: The existing text requires the use of shielded
conductors, both single and multiconductor, 'in cable trays for
over 600 Volts. The intent is correct, namely to provide a
ground path for fault currents without an external arc.
Non-shielded single conductors and multiconductor cables would
arc to the tray and should be shielded, however, multiconductor
cables enclosed in a smooth metallic sheath or a welded and
corrugated metallic sheath as defined for Type MC cable i n
Section 334-22 would have the sheath as a shield to safely
conduct fault currents and contain any arc within the cable.
The two sheaths specified provide a grounding path in excess of
Table 250-95.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Already covered by f i r s t paragraph of s.ame
Section.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
(a) All fixed wiring installed in the open space above
hazardous locations shall be in metallic raceways, t~pe MI cable
or ALS cable. Cellular metal floor raceway may be used only for
supplying ceiling outlets or extensions to the area below the
floor, but such raceway shall have no connections leading into
or through any hazardous locations above the floor.
(b) Equipment which may produce arcs, sparks or particles
of hot metal, such as lamps, l ampholders for fixed lighting,
cutouts, switches, receptacles, charging panels, generators,
motors or other rotating equipment having make-or-break or
sliding contacts, shall be of the t o t a l l y enclosed type or shall
be provided wSth suitable guards or screens to prevent the
escape of sparks or hot metal particles.
SUBSTANTIATION: This proposal is intended to correct an
emission in the Code which does not generally recognize and
provide for the hazard of dropping molten metal or hot metal
particle into hazardous vapors when overhead electrical wiring
or equipment above and out of the hazardous location, develops a
fault. This requirement is found in certain specific locations
but i t should be stated in Article 500 for all hazardous
locations as the danger is the same.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting co~ent is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 17.
r NEGATIVE: Boylston.
COMMENT ON VOTE:
JORIMAN: The submitter of this proposal was to supply
additional information to support the Code change. As none was
received the IAEI Code Panel member had no choice but to concur
with the rest of the Panel and reject Proposal No. 23.
EXPLANATION OF VOTE:
BOYLSTON: See Comment-on Proposal No. 22.
501-5(a)(1), Exception-(New): Accept
CMP 14
SUBMITTER: P. J. Schram, Underwriters Laboratories Inc.
]~TO]~'A-L-~." 29 Add a new exception as follows:
--l~-xc-epl~ion: Conduit runs entering an explosion-proof enclosure
for switches, circuit breakers, fuses, relays, or other
apparatus which may produce arcs or sparks need not be sealed i f
the current interrupting contacts are:
a. Enclosed within a chamber hermetically sealed against the
entrance of gases or vapors; or,
b. Immersed in oil in accordance with Section 501-6(b)(1) and
(2).
SUBSTANTIATION: We believe i t is the intent of the f i r s t
sentence of Section 501-5(a)(1) and Section 501-5(a)(2) to
require seals in conduit runs 1 1/2-inch
trade size and smaller only when the conduit runs enter
enclosures containing a source of ignition under normal
operating conditions.
The Code does not require seals on
conduit runs 1 1/2-inch trade size and smaller entering
explosion-proof junction boxes i f the boxes contain only wiring
and splices. I f the interruption of current occurs within an
hermetically sealed chamber or the contacts are properly oil
immersed, there is no ignition s~urce under normal operating
conditions, and the construction is essentiallx the same as an
explosion-proof outlet box containing only wiring and splices.
Conductors which may be flexed as a condition of normal
operation, such as mercury-tube switch leads, could eventually
f a i l and result in arcing, but we do not believe i t was the
original intent of the Code to consider such leads as "apparatus
which may produce arcs, sparks, or high temperatures." For
example, the Code does not appear to require !eads in
explosion-proof flexible connection f i t t i n g s which may be flexed
under normal conditions to be sealed.
We believe that Section 501-B(a)(1) of the Code should be
clarified so that specifiers, installers, and inspectors will
have a clear indication as to whether or not seals are required
in' conduit runs entering explosion-proof enclosures housing
mercury-tube switches, and in similar situations, and so that
testing laboratories such as Underwriters Laboratories Inc. will
be able to publish more detailed test requirements for such
products based on the intended method of installation. I f i t is
the intent of the Code that seals be required in such
circumstances (the above proposal is based on seals not being
required), the Code should be revised to so indicate.
PANEL RECOMMENDATION: Accept as Revised:
Between the words "runs" and "entering" add the words "1 I/2
inches and smaller".
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 501 -- CLASS I LOCATIONS
501-3(a): Accept
CMP 14
SUBMITTER: D. H. Mclntosh, E. I. du Pont de Nemours & Co.
24 Revise f i r s t sentence of second paragraph as
Enclosures approved for Class I, Division, 1 locations
include: (a) explosion-proof enclosures, and (b) purged and
pressurized enclosures.
SUBSTANTIATION: To c l a r i f y intent.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
501-3(b)(6)(2): Accept
CMP 14
SUBMITTER: TSC-Nominal Voltage
I
~
25 Add "nominal" after "120 volts."
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: CMP 14 recommends that by changing Section 110-4
to read "Throughout this Code the voltage considered shall be
the nominal system voltages at which the circuit operates" would
eliminate the need to add nominal each time voltage is used.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
SOI-4(a) and (b): Reject
CMP 14
SUBMITTER: John J. Brett,'Berger Industries, E.T.P. Div.
PR]~P-O-~A-L-~
•. 26 Revise (a) and (b) as follows:
~ s s
I Division I locations, threaded rigid metal conduit,
threaded steel intermediate metal conduit with integral or
associated couplings or type MI cable with termination f i t t i n g s
approved for the location shall be the wiring method employed.
SUBSTANTIATION: We have tested our product ourselves and find
i t conforms to the requirements laid down by U.L. We have
requested U.L. to set up a fact finding investigation and
testing for our product.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: No evidence to support the suggested change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
501-5(a)(S)-(New): ReJect
'
CHP 14
SUBMITTER: Robert G. MacManus,Pawtucket, RI
30 Add a new (5) as follows:
T~TT-Nember of Conductors Allowed In One Sea]. The number of
conductors allowed in any one seal shall be limited to nine.
SUBSTANTIATION: No restriction has ever been placed on the
number of conductors in a raceway which is required to be
sealed. I t would be next to impossible to make an effective
seal with the installation of a large number of conductors. As
an example, 154 No. 14 conductors may be installed in a 2 inch
conduit. The writer has seen 83 conductors in a combination of
No. 14 - No. 12 and No. 10 wires. A seal was attempted in order
to comply w~th Section 501-5(a)(2).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is too restrictive.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
501-4(b): Accept
CMP 14
SUBMITTER: TSC-Nominal Voltage
~
27
I~ the last paragraph add "nominal" after "600
I SUBSTANTIATION:
To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: See Panel Comment on Proposal 25.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
232
500-7-(New): Reject
CMP 14
SUBMITTER: Southwestern Section IAEI
PROPOSAL: 23 500-7. Wiring and Equipment Above Hazardous
501-4(b), Exception No. 2-(New): Reject
CMP i%
SUBMITTER: James M. Daly, The Okonite Co.
PROPOSAL: 28 Delete last paragraph of 501-4(b). Replace with
a new exception as follows:
Exception No. 2: Where installed in cable tray, Type MV
single conductors and multiconductor cables rated 2001 Volts and
over shall have metallic shielding on each conductor.
Multiconductor Type MC cable with a continuous metallic sheath
shall be permitted to have nonshielded conductors.
SUBSTANTIATION: The existing text requires the use of shielded
conductors, both single and multiconductor, 'in cable trays for
over 600 Volts. The intent is correct, namely to provide a
ground path for fault currents without an external arc.
Non-shielded single conductors and multiconductor cables would
arc to the tray and should be shielded, however, multiconductor
cables enclosed in a smooth metallic sheath or a welded and
corrugated metallic sheath as defined for Type MC cable i n
Section 334-22 would have the sheath as a shield to safely
conduct fault currents and contain any arc within the cable.
The two sheaths specified provide a grounding path in excess of
Table 250-95.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Already covered by f i r s t paragraph of s.ame
Section.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
(a) All fixed wiring installed in the open space above
hazardous locations shall be in metallic raceways, t~pe MI cable
or ALS cable. Cellular metal floor raceway may be used only for
supplying ceiling outlets or extensions to the area below the
floor, but such raceway shall have no connections leading into
or through any hazardous locations above the floor.
(b) Equipment which may produce arcs, sparks or particles
of hot metal, such as lamps, l ampholders for fixed lighting,
cutouts, switches, receptacles, charging panels, generators,
motors or other rotating equipment having make-or-break or
sliding contacts, shall be of the t o t a l l y enclosed type or shall
be provided wSth suitable guards or screens to prevent the
escape of sparks or hot metal particles.
SUBSTANTIATION: This proposal is intended to correct an
emission in the Code which does not generally recognize and
provide for the hazard of dropping molten metal or hot metal
particle into hazardous vapors when overhead electrical wiring
or equipment above and out of the hazardous location, develops a
fault. This requirement is found in certain specific locations
but i t should be stated in Article 500 for all hazardous
locations as the danger is the same.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting co~ent is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 17.
r NEGATIVE: Boylston.
COMMENT ON VOTE:
JORIMAN: The submitter of this proposal was to supply
additional information to support the Code change. As none was
received the IAEI Code Panel member had no choice but to concur
with the rest of the Panel and reject Proposal No. 23.
EXPLANATION OF VOTE:
BOYLSTON: See Comment-on Proposal No. 22.
501-5(a)(1), Exception-(New): Accept
CMP 14
SUBMITTER: P. J. Schram, Underwriters Laboratories Inc.
]~TO]~'A-L-~." 29 Add a new exception as follows:
--l~-xc-epl~ion: Conduit runs entering an explosion-proof enclosure
for switches, circuit breakers, fuses, relays, or other
apparatus which may produce arcs or sparks need not be sealed i f
the current interrupting contacts are:
a. Enclosed within a chamber hermetically sealed against the
entrance of gases or vapors; or,
b. Immersed in oil in accordance with Section 501-6(b)(1) and
(2).
SUBSTANTIATION: We believe i t is the intent of the f i r s t
sentence of Section 501-5(a)(1) and Section 501-5(a)(2) to
require seals in conduit runs 1 1/2-inch
trade size and smaller only when the conduit runs enter
enclosures containing a source of ignition under normal
operating conditions.
The Code does not require seals on
conduit runs 1 1/2-inch trade size and smaller entering
explosion-proof junction boxes i f the boxes contain only wiring
and splices. I f the interruption of current occurs within an
hermetically sealed chamber or the contacts are properly oil
immersed, there is no ignition s~urce under normal operating
conditions, and the construction is essentiallx the same as an
explosion-proof outlet box containing only wiring and splices.
Conductors which may be flexed as a condition of normal
operation, such as mercury-tube switch leads, could eventually
f a i l and result in arcing, but we do not believe i t was the
original intent of the Code to consider such leads as "apparatus
which may produce arcs, sparks, or high temperatures." For
example, the Code does not appear to require !eads in
explosion-proof flexible connection f i t t i n g s which may be flexed
under normal conditions to be sealed.
We believe that Section 501-B(a)(1) of the Code should be
clarified so that specifiers, installers, and inspectors will
have a clear indication as to whether or not seals are required
in' conduit runs entering explosion-proof enclosures housing
mercury-tube switches, and in similar situations, and so that
testing laboratories such as Underwriters Laboratories Inc. will
be able to publish more detailed test requirements for such
products based on the intended method of installation. I f i t is
the intent of the Code that seals be required in such
circumstances (the above proposal is based on seals not being
required), the Code should be revised to so indicate.
PANEL RECOMMENDATION: Accept as Revised:
Between the words "runs" and "entering" add the words "1 I/2
inches and smaller".
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
ARTICLE 501 -- CLASS I LOCATIONS
501-3(a): Accept
CMP 14
SUBMITTER: D. H. Mclntosh, E. I. du Pont de Nemours & Co.
24 Revise f i r s t sentence of second paragraph as
Enclosures approved for Class I, Division, 1 locations
include: (a) explosion-proof enclosures, and (b) purged and
pressurized enclosures.
SUBSTANTIATION: To c l a r i f y intent.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
501-3(b)(6)(2): Accept
CMP 14
SUBMITTER: TSC-Nominal Voltage
I
~
25 Add "nominal" after "120 volts."
SUBSTANTIATION: To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: CMP 14 recommends that by changing Section 110-4
to read "Throughout this Code the voltage considered shall be
the nominal system voltages at which the circuit operates" would
eliminate the need to add nominal each time voltage is used.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
SOI-4(a) and (b): Reject
CMP 14
SUBMITTER: John J. Brett,'Berger Industries, E.T.P. Div.
PR]~P-O-~A-L-~
•. 26 Revise (a) and (b) as follows:
~ s s
I Division I locations, threaded rigid metal conduit,
threaded steel intermediate metal conduit with integral or
associated couplings or type MI cable with termination f i t t i n g s
approved for the location shall be the wiring method employed.
SUBSTANTIATION: We have tested our product ourselves and find
i t conforms to the requirements laid down by U.L. We have
requested U.L. to set up a fact finding investigation and
testing for our product.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: No evidence to support the suggested change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
501-5(a)(S)-(New): ReJect
'
CHP 14
SUBMITTER: Robert G. MacManus,Pawtucket, RI
30 Add a new (5) as follows:
T~TT-Nember of Conductors Allowed In One Sea]. The number of
conductors allowed in any one seal shall be limited to nine.
SUBSTANTIATION: No restriction has ever been placed on the
number of conductors in a raceway which is required to be
sealed. I t would be next to impossible to make an effective
seal with the installation of a large number of conductors. As
an example, 154 No. 14 conductors may be installed in a 2 inch
conduit. The writer has seen 83 conductors in a combination of
No. 14 - No. 12 and No. 10 wires. A seal was attempted in order
to comply w~th Section 501-5(a)(2).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Proposal is too restrictive.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
501-4(b): Accept
CMP 14
SUBMITTER: TSC-Nominal Voltage
~
27
I~ the last paragraph add "nominal" after "600
I SUBSTANTIATION:
To conform to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: See Panel Comment on Proposal 25.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
232
501-6(b): Accept
CMP 14
SUBMITTER: W.A. Short, Crouse-Hinds Company
P ~ .
34 Add a new 501-6(b)(5):
---(TT-~uses Internal to Lighting Fixtures. Listed cartridge
fuses shall be permitted within lighting fixtures.
SUBSTANTIATION: The principal reason for internal fusing of
lighting fixtures is to remove the faulty fixture from the
circuit before i t results in a branch circuit outage, and
darkness in an entire area.
U/L requires that listed cartridge fuses (such as Buss KTK) be
f i l l e d with quartz or other granular matter which prevents flame
from erupting from the cartridge.
PANEL RECOMMENDATION: Accept as Revised:
Substitute the word "Approved" for the word "Listed" and add
the words " f i l l e d with noncembustible granular material" between
the words "fuses" and "shall."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
MILLER: Although I am voting affirmatively, I believe the
Panel Recommendation restricts the design more than necessary.
A more general statement of desired performance would be
preferable.
501-5(c)(2): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
31 See the Technical Subcommittee "Reco~ndations"
un-u'n-~--r'-i~e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
(2) Compound. Sealing compound shall be approved and shall
provide a seal against passage of gas or vapors through the seal
f i t t i n g , shall not be affected by the surrounding atmosphere or
liquids, and shall not have a melting point of less than 93°C
(200°F).
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
501-5(e)(2): Reject
CMP 14
SUBMITTER: C.E. Muhleman, Marion, IN
PI~rOIIO-S'-At-~32 Revise as follows:
- - T ~ - - Installed ca~les which limit gas or vapor flow through
the cable core t o 0.007 cubic feet per hour (0.0551 x 106
cubic metre per second) at a pressure of 6 inches of water (1490
pascals) at 60~F (15.5°C) shall not be required to be sealed
except as required in (e)(1) above.
SUBSTANTIATION: The new wording is intended to assure that the
cables are intact even after the rigors of installation. The
new wording also avoids the ambiguous phrase "gas/vapor-tight
continuous sheath."
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necesslty.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ADAMS: The parenthetical phrase "0.007 cubic feet per hour of
air at a pressure of 6 inches of water" causes great concern and
I believe i t should be l e f t out. The gas passing through the
interstices of the wire strands is included in the above phrase
but when referred to the seal f i t t i n g I t is not included.
501-6(b)(3): " Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
35 See the Technical Subcommittee "Recommendations"
un-un'd'e'r--'t-F1e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
In line 4 delete "for the purpose and." In line 5 delete " i f
they are approved for the purpose,."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
501-8(b): Reject
CMP 14
SUBMITTER: Ct~° 14
35A Revise 501-8(b)Motors and Generators, Class I ,
~ 2 .
Add a third paragraph as follows:
In Class I , Division 2 locations, motors, generators and other
rotating electric machinery not approved for Class I, Division 1
locations shall be permitted only i f :
I . Ignition temperature of the gas or vapor involved is 280°C
(536°F) or higher, and
2. Nameplate is marked not over 80°C temperature rise (85°C
for totally enclosed nonventilated construction) by resistance
at 100% lo~d or goac temperature rise by resistance at Service
Factor load, or
3. Nameplate is marked to indicate Class A or Class B
Insulation System and MaximumAmbient Temperature.
Exception: Motors and generators with Class F or Class H
Insulation System or in installations involving gases or vapors
having ignition temperatures below 280°C (536°F) shall be
permitted i f the maximum rated load operating temperature of any
exposed surface (including internal parts of all constructions)
will not exceed 80 percent of the ignition temperature in
degrees Celsius oh the gas or vapor involved.
SUBSTANTIATION: The present wording of 501-8(b) was based on
relation of exposed motor surface temperatures and gas or vapor
ignition temperatures prevalent some years ago; under the
conditions then existing, experience has proven that the present
wording of this section of the Code provided safe installations.
However, the ignition temperature of some of the newer gases
is approaching the operating temperature of some higher
temperature capability motors. Under these more recent
conditions, safety hazards may exist when applying
non-explosion-proof motors per the present wording of the Code.
The proposed change, then, limits use of open or
non-explosion-proof enclosed motors in Class I , Division 2
locations to the combination of vapor ignition temperature and
motor operating temperature consistent with past practice, or
provides a safe system by limiting motor temperatures to 80
percent of the gas or vapor ignition temperature.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Already covered by Section 500-2(a) and (c).
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Short.
EXPLANATION OF VOTE:
SHORT: The referenced 500-2(a) and (c) are effective for
listed or certified equipment, but will in no way, prevent the
application of standard and/or stock squirrelcage motors in
Class I f , Division 2 areas. Only a specific limitation in
501-8(b) can be effective in minimizing this potential hazard.
501-5(e)(4) FPN: Reject
CMP 14
SUBMITTER: K.C. Starkey, The Rockbestos Co.
I~-O-P-O-~FA-C~- 33 Revise fine print note as follows:
~eath
mentioned in (d) and (e) above may be either metal
or a nonmetallic material . i f approved for the purpose.
SUBSTANTIATION: Cables with a gas/vapor tight continuou~ sheath
that are sealed in the hazardous location need not be scaled
when they leave the hazardous location. This applies to
continuous metallic sheathed cable and Type TC cable that is
approved for the purpose.
In the case of a continuous metallic sheath cable the
continuous metal sheath provides the gas/vapor tight sheath. In
approved nonmetallic Type TC cable the cable jacket provides
this gas/vapor tight sheath.
However in a noncontinuous metallic sheathed cable such as
interlock armor the gas/vapor tight barrier must be provided by
the nonmetallic Jacketing material.
With a continuous metallic sheath cable a Jacket, when
provided, is for mechanical and/or corrision protection.
Therefore the impervious Jacket over an interlock cable
construction should re(Iuire the same type and thickness as a
Type TC cable.
A comparison between the UL required Jacket thickness for
mechanical and/or corrosion protection of continuous sheathed
metallic cable and the gas/vapor tight Jacket of a Type TC cable
is listed below.
CONTINUOUS METAL SHEATHCABLE
Core O.D.
0-0.425
0.426-0~750
0.751-1.500
1.501-2.250
2.251-3.000
3.001-& larger
Jacket Thickness
40
50
50
60
75
85
mils
mils
mils
mils
mils
mils
NONMETALLIC TYPE TC CABLE
Core O.D.
0-0.425
0.426-0.700
0.701-1.500
1.501-2.500
2.501-& larger
Jacket Thickness
45
60
80
110
140
mils
mils
mils
mils
mils
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Supporting comment is not persuasive as to
necessity.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
501-8ib): Accept
CMP 14
SUBMITTER: CMP 14
F RTOI~S'31t-~: 35B Revise the last part of the last sentence of
paragraph one to read "...are provided with enclosures approved
for Class I Division 2 locations in accordance with Section
501-3(b)."
233
SUBSTANTIATION: To correct error made by Panel in 1978 NEC.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
utilizing extra hard-usage multicondutor cords and cables have
been used extensively and successfully in the United States and
throughout the world. They are being used in various
configurations in such diverse fields as mining, contracting
(building, road, and excavating), dewater!ng, deep-well, and
wastewater handling (stormwater, sewage, industrial effluent,
etc.).
Especially with the advent of OSHA, and it~ support of the
NEC, more and.more inspection and standards authorities are
expecting specific guidance from NEC in areas not previously
explicitly defined. I t is the intention of the suggested
~endment to provide this speciflc guidance.
Many authorities in the wastewater field (sewage, stormwater,
etc.) in recognizing especially the contribution to maintenance
of submersible pumps, have stipulated that in any wet-well
installation they be easily removed without the need for
personnel to enter or dewater the wet-well. This is provided by
all member companies in the industry by means of guide-rail
remote guidance system and a simple automatic discharge
connection system which allows indexing and a tight connection
(or removal) to be automatically accomplished between the pump
discharge flange and the effluent piping flange.
In order to maintain the workability of the system and the
intent of the specifying Authorities, i t is imperative that
flexible cord or cable be used between the place where the
service enters the wet-well from the pump control (gas-tight
conduit seal or--in the case of Class I, Division I
locations--explosion-proof junction or splice box hard wired to
the pump cable with a suitable compression cable-entry) and the
pump cable-entry assembly.
This will allow the pump to be lifted from the wet-well
through the opened cover in the access frame in the ~round-level
slab by its chain or wire-rope without personnel entering or
dewatering the wet-well.
In the case of Class I , Division 1 locations, the pump is
either explosion-proof and suitable for the installation (there
are none Approved at the present time) or redundant low-level
shut-off sensing is provided which guarantees the uppermost
portion of a standard submersible pump is always,submerged.
These approaches are specified and accepted by the
Administrative Code for the State of Wisconsin and the
Department of Industrial Safety for the State of California for
some time. .
Extra hard-usage cord and cable of the S, SO, ST, STO, W, G,
PCG, etc., classes have been used for many years in submersible
wastewater handling with a perfect safety record in classified
locations. Certainly the application is one where the usage is
far less demanding than others like coal mining and general
contracting where these same cables have been universally
accepted (MESA, Penna. Bureau of Mines, etc.) and successful.
PANEL RECOMMENDATION: Accept as Revised:
Revise Exception by adding a new paragraph as follows:
"Electric submersible pumps with means for removal without
entering the wet-pit shall be considered portable utilization
equipment."
VOTE ON PANELRECO~ENDATION: UnanimouslyAffirmative.
COMMENTON VOTE:
ADAMS: I favor the intent of the Proposal but I feel that the
Exception should be in two parts with one part in Section
501-I0(a).
SCHRAM: My notes indicate the Panel Recemmendation was to add
the quoted paragraph to Section 501-11, not to the Exception to
Section 501-11.
501-9(a)(3): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
R~
i -RO-POSAL: 36 See the Technical Subcommittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
lOO,
SUBSTANTIATION: See the TSC "findings '~ under the definition of
"Approved for the Purpose" in Article 100:
PANEL RECOMMENDATION: Accept as Revised:
In line 8 delete "for the purpose and."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
,
501~9(a)(4): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
~ O S A L : 37 See the Technical Subcommittee "Recommendations"
un--6-de-{~-F[e definition of "Approved for the Purpose" in Article
I00,
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
In line 2 delete "for the purpose and."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
501-9(b)(3): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
38 See the Technical Subcommittee "Recommendations"
~ e r the definition of "Approved for the Purpose" in Article
I00.
-~
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article I00.
PANEL RECOMMENDATION: Accept as Revised:
I In line 6 insert "an approved" before " f i t t i n g " and delete
"approved for the purpose."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
\
501~9{b)(4): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
39 See the Technical Subcommittee "Recemmendations"
j ~ e
definition of "Approved for the Purpose" in Article
100,
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in A~ticle 100.
I PANEL RECOMMENDATION: Accept as Revised:
Delete paragraph and renumber (5) and (6) to (4) and (5).
PANEL COMMENT: This paragraph does not seem to provide any
specific hazardous location requirements. General requirements
for support of light fixtures appear elsewhere in the Code.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
501-10(b)(1)a: Accept
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
]~TOI~S'Ai-[." 40 In the f i r s t sentence, delete the words "in
degrees Celsius"; also delete the words "likely to be" and
replace with the words ;'which is."
SUBSTANTIATION: The use of the word "likely" renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
*See Border County Div. ~EI substantiation for CMP 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Accept as Revised:
Leave in "in degrees Cels!us."
PANEL COMMENT: The words "in degrees Celsius" are essential,
since 80 percent of a temperature in degrees Fahrenheit and 80
percent of a temperature in degrees Celsius are not the same
temperature.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
I
501-16(b): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, MO
~ 4 2
Revise the last sentence as follows:
~flexible
conduit is used as permitted in Section
501-4(b), internal or external bonding jumpers complying with
the provisions of Section 250-79 shall be installed in parallel
with the conduit..
And add a fine print note as follows:
See Section 250-78.
SUBSTANTIATION: The present wording does not cover all of the
requirements fo~ bonding jumpers. For,exa,~)le, Section
250-79(e) requires external equipment bonding jumpers to be not
more than 6 feet in length and t 9 be routed with the conduit.
The bonding jumpers that are required for flexible conduit
should comply with Section 250-79 which specifies the material,
attachment methods, size, and installation requirements for
equipment bonding jumpers.
The proposed fine-print reference to Section 250-78 correlates
with the bonding requirements for hazardous locations that are
specified in Article 250.
PANEL RECOMMENDATION:.Accept.
VOTE ON PANELRECOF~4ENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Adams.
EXPLANATION OF VOTE:
ADAMS: Section 501-I refers to the general rules of this Code
and I do not think these bonding requirements are of a nature
peculiar to Class I locations.
501;11, Exception No. 2-(New): Accept
CMP 14
Secretary's Note: I t was the action of.the Correlating
Committee that further consideration be given to the co,1~ents
expressed in Mr. Schram's voting.
SUBMITTER: H. W. T. Dutton, Chicago, IL
41 Add new exception as follows:
~ i o n
No. 2: Electric submersible wastewater pumps with
means for automatic removal without entering or'dewatering the
wet-pit shall be considered portable utilization equipment. In
Class I , Div. 1 locations, the pumps (unless approved for the
location) shall remain completely submerged under all operating
conditions with the liquid level at least four inches above "any
portion of the pump--excepting the extra hard-usage cord or
cable. See Section 501-13 for flexible cords exposed to liquids
having a deleterious effect on the conductor insulation.
SUBSTANTIATION: For over 30 years electric submersible pumps
234
501-16(c): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, MO
43 Revise as follows:
~ightning
Protection. Each ungrounded service conductor
of a wiring system in a Class I location, where supplied from an
overhead line in an area where lightning disturbances are
prevalent, shall be protected by a surge arrester that complies
with the provisions of Article 280. The surge arresters shall
be connected to the service conductors at an accessible point on
the load side of the service drop, and the arrester grounding
connections shall compl~ with the applicable provisions of
Article 280.
SUBSTANTIATION: A CMP 5 Subcommittee has submitted proposals to
update Article 280 to current nomenclature and practices.
Article 280 covers the selection, installation, and connection
of surge attesters. The proposed revision has references to
Article 280 which makes the selection, installation, and
connection of surge arresters in Class I locations consistent
with the updated provisions in Article 280.
PANEL RECOMMENDATION: Accept as Revised:
In the last sentence delete "at an accessible point on the
load side of the service drop."
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Adams.
EXPLANATION OF VOTE:
ADAMS: Section 501-I refers to the ~eneral rules of this Code
and I do not think the Lightning Protection requirements are of
a nature peculiar to Class 1'locations.
501-16(d): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, MO
IqTOlfO'S'A'CT". 44 Revise as follows:
"~----Grounded Service Conductor, Connections at Service
Equipment.. Where a Class I location is supplied from an
alternating-current service and the supply system is solidly
grounded, the grounded service conductor shall be run to each
service according to the requirements in Section 250-23(b) and
shall be grounded according to the requirements in Section
250-23(a). Bonding connections to the grounded service
conductor at the service equipment shall comply with Sections
250-50(a) and 250-53. Metal enclosures for service conductors
and service equipment shall be bonded in accordance with the
applicable provisions in Article 250, Part G.
Exception: Where the installation complies with all of the
conditions specified in Section 501-16(f) and the system
grounded conductor is not used as a circuit conductor, a
grounded service conductor shall not be required to be run to
the service eFl.uipment.
SUBSTANTIATION: This proposed revision correlates with my
proposal to revise the text of Section 501-16(f). The proposed
rewording and the references to sections in Article 250
clarifies the intent of Section 501-16(~) because the referenced
sections contain complete specifications for the general
requirements that are covered in the present text. The proposed
revision does not change the intent of the present text.
PANEL RECOMMENDATION: Accept as Revised:
Change reference to 501-16(f) in the Exception to 501L16(e) to
correlate with Proposals 45 and 46.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
(I) The grounded service conductor shall be connected to a
grounding electrode at the transformer supplying the service.
(2) A grounding conductor shall be run with the service
conductors from the supply transformer to the service equipment,
and shall be sized in accordance with the requirements for
sizing the grounded service conductor in Section 250-23(b). The
grounding conductor shall be bonded to the grounded service
conductor at the transformer supplying the service and to the
equipment grounding conductor(s) at the service equipment.
(3) The service equipment enclosures, the grounding
conductor specified in (2) above, and the equipment grounding
conductor(s) shall be bonded together and connected to a
grounding electrode by a grounding electrode conductor.
SUBSTANTIATION: Objectional currents over the grounding
conductors are caused by multiple grounding connections to the
system grounded conductor, which is the grounded service
conductor in Section 5O1-1B(d). One way to prevent these
obJectional currents from flowing is to ground the grounded
service conductor at the supply transformer only, and abandon
the grounding connections to the grounded service conductor that
are specified in Sections 250-23(a), 250-50(a), and 250-53".
I t is perfectly safe to ground the grounded service conductor
at the supply transformer only, provided the conditions stated
in (2) and (3) of the proposed revision are met. These
conditions assure an adequate conductor for ground-fault current
to flow from the service equipment to the supply transformer,
and the potential between the service equipment enclosures and
ground will not be unsafe during ground-fault, conditions. ~The
surge arresters that are specified in Section 501-16(c) provide
additional protection at the service equipment by .limiting
voltages due to lightning and line surges.
The present wording of Section 501-16(f) requires the grounded
service conductor to be grounded at the service equipment i f the
supply system is grounded at any other point. This multiple
system grounding requirement is likely to cause objectional
currents over the grounding conductors i f the service conductors
a÷e installed in metal raceways from the service supply to the
service equipment.
This proposal correlates with'my proposal to revise Section
501-16(d).
PANEL RECOMMENDATION: Accept as Revised:
I The t i t l e of this Section will be: "Multiple Grounds." In
order to correlate with Proposal 45, the number of this Section
will be 501-16(e).
VOTE ON PANELRECOMMENDATION: Unanimpusly Affirmative.
501-17-(New): Reject
CM~ 14
SUBMITTER: KennethL. Paape, Allen Bradley Co.
!~-O-P-O-S-A[-~.'47 Add new section as follows:
Ground-Fault Protection of Equipment, Class I ,
Divisions I and 2.
Ca) Ground-fault protection shall be provided for each
solidly grounded branch circuit where conductors are not
protected against overcurrent i~ accordance with their
ampacities and the circuit is rated more than 50 volts to
ground, but not exceeding 600 volts phase-to-phase in a Class I ,
Division 1 or 2 location. The ground-fault protection shall
operate to open all ungrounded conductors of the faulted
circuit. The maximum setting of the ground-fault protection
shall be 10 amperes. Anytime-delay in the operation of the
ground-fault protection shall be coordinated with the
interrupting rating of the branch-circuit disconnecting or
controlling means and the rating or setting of the device that
provides overcurrent protection for the branch circuit.
Exception No. I : Where the circuit overcurrent protective
device has a rating mr setting not exceeding 100 ~ e r e s .
Exception No. 2: Where an orderly shutdown is required. (See
Section 240-12).
(b) The ground-fault protection system installed shall meet
the performance requirenients of Section 230-95 (b) and (c).
SUBSTANTIATION: I t has long been recognized in the electrical
industry that arcing ground faults occur which damage equipment
extensively because the. ground fault current is limited by the
impedance of rigid conduit or is not sustained for a sufficient
period of time to cause the overcurrent protective device to
clear the fault. As a consequence, damage such as shown in the
attached photographcan occur with the emission of sparks and
molten metal. Such emission can ignite vapors or gases which
may be~present in Class I HazardousLocations. The higher the
rating or setting of the overcurrent protective device the
greater the probability of extensive damage before the
overcurrent protective device responds to the ground-fault
current.
Each of the exceptions to the general rule of protecting
conductors against overcurrent in accordance with their
ampacities (see Section 240-3) exists for a good purpose, but
involves some degree of risk. Motor branch circuits are
particularly vulnerable because motor driven equipment often
includes a source of vibration which in turn can cause
insulation to abrade in conduit with the result as shown in the
photograph. Providing ground-fault protection for equipment in
such situations will reduce the risk inherent in circuits where
conductors are not protected in accordance with their ampacities.
Similar proposals have been submitted for Class I I and Class
I l l hazardous locations.
501-16(e): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, /40
45 DeleteSection 501-16(e).
~IATION:
The grounded service conductor of a grounded
system is required to be run to each service by the provisions
of Section 250-23(b), so the condition stated in Section
501-16(e) is not permitted. Article 250 also contains adequate
provisions for grounding and bonding that apply to Class I
locations. For example, Section 250-23(a) requires the grounded
~ervice conductor to be grounded at each service. Sections
250-50(a), 250-50(b), 250-53(a), and 250-53(b) cover bonding and
interconnections between the equipment grounding conductors, the
grounded service conductor, the grounding electrode conductor,
and the service equipment enclosures. Sections 250-71, 250-72,
250-75, 250-76, 250-77, 250-7B, and 250-79 cover bonding
requirements for the noncurrent-carrying metal parts of
equipment, raceways and other enclosures on the supply side and
on the load side of the service equipment.
My proposed revision for Section 501-16(f) covers conditions
which must be complied with where a grounded service conductor
of a grounded system is not run to the service equipment.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
501-16(f): Accept
;
CMP 14
SUBMITTER: Robert B. West, St. Louis, /40
PROPOSAL: 46 Revise the text of (f) as follows:
in the application of Section 250-21, i t is necessary
to abandon the grounding and'bonding connections to the grounded
service conductor that are specified in (d) above, the
installation shall comply with all of the following conditions:
235
r
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 502 -- CLASS I I LOCATIONS
502-4: Accept
CMP 14
SUBMITTER: CMP 14
PITOI}O
' -~TAL-~: 51A Revise second sentence to read: "Cable tray
I ~ t
be permitted in Class I f , Division 1 or 2 locations.
SUBSTANTIATION: Cable trays are dust collectors and should not
be used in Class I I areas. •
PANEL RECOMMENDATION: Accept as Revised:
"Tray" should read "trays."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-I: Reject
CMP 14
SUBMITTER: G. A. Karstens, American, Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 48 " After the third paragraph add a paragraph as
502-4(a): Reject
CMP 14
SUBMITTER: K. C. Starkey, The Rockbestos Co.
52 Revise f i r s t sentence of (a) as follows:
In Class I f , Division 1 Iocatidns, threaded rigid metal
conduit, threaded steel intermediate metal conduit, Type MI, or
Type MC cable employing a continuous smooth or corrugated
aluminum sheath with termination f i t t i n g s approved for the
location shall be the wiring method employed.
SUBSTANTIATION: Type MC cable employing a continuous smooth or
corrugated aluminum sheath has a tight f i t t i n g core and is
sheathed in an impervious aluminum tube that has superior crush
and impact resistance.
I t has been used widely in Class I,
Division 2 and Class I I , Division 2 locations by the petroleu M,
petrochemical, coal and grain industries. Present continuous
welding methods make i t possible to maintain the accurate OD of
the cable sheath within the UL Standard 886 for maximum
diametric clearance for cylindrical joints. In earlier
manufacturing processes this was not possible; therefore, the
termination f i t t i n g manufacturers could not properly design a
termination f i t t i n g with prope~ barrel length and clearance to
comply with the UL Standards.
Termination f i t t i n g manufacturers, including Crouse-Hinds,
have assured us that i f the sheath OD can be held constant, a
termination f i t t i n g can be designed to comply with UL Standards.
The acceptance of Type MC cable employing a smooth or
corrugated aluminum sheath for use in Class I I , Division i
locations will provide "an alternate wiring system that is saYe
and economical to install. The sheath provides a completely
impervious tube from connection to ~onnection and with approved
termination f i t t i n g s Will eliminate the possibility of dusts
entering the system through joints and couplings.
We are submitting the following UL Test Reports* relative to
the physical properties of continuous aluminum sheathed Type MC
cable including impact, crushing, flexing and dielectric
withstand;
*Reports have been-supplied to CMP.chairman.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not ~gree with the supporting
comment.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
For further information see NFPA496 Purged and Pressurized
Enclosures for Electrical Equip~mnt - 1974.
SUBSTANTIATION: Material in this bulletin will aid materially
in describing the proper requirements for motor control centers
for Class I I locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMEN~: Already covered by Section 500-I.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-i: Accept
CMP 14
Secretary's Note:. I t was the action of the Correlating
Committee that the Panel shall .review their Recommendation with
a view towards correcting grammatical errors.
SUBMITTER: W.A. Short, Crouse-Hinds Company
49 Add a new sentence to the end of 502-1:
--~r~-e-Fe-are only Division 1 locations where Class I I , Groups E
and F dusts are present. See Section 500-5(a)3.
SUBSTANTIATION: The information in 500-5(a)3 is not well
understood in the industry. This wording does not change the
intent, but helps to c l a r i f y the information already in the Code.
PANEL RECOMMENDATION: Accept as Revised:
After "dusts" add "having a r e s i s t i v i t y less than 105
ohm-cm."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-2(b)(3)(2): Accept
CMP 14
SUBMITTER: TSC-Nominal Voltage
50 Add "nominal" after "600 volts."
~O~-S~I~NTIATION: To conform'to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: See Panel Comment on Proposal 25.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
502-3: Accept
j
CMP 14
SUBMITTER: Robert'B. West, St. Louis, MO
PROPOSAL: 51 Revise as follows:
T-3.
Surge,Protection, Class I I , Divisions I and 2. In
geographical locations where lightning disturbances are
prevalent, and where supplied by overhead services, electric
systems in Class I I locations shall be protected against
high-voltage surges. This protection shall include surge
arresters, interconnectlon of all grounds, and surge-protective
capacitors.
Surge arresters, including their installation and
connections, shall comply with Article 280.
Surge-protective capacitors shall be of a type designed for
the specific duty. The capacitor grounding conductors shall be
connected to the grounding ~onductors for the surge arresters.
Surge-protective capacitors" shall be connected to each
ungrounded service conductor at the service entrance or service
equipment. The capacitors shall be protected by 30-ampere fuses
of suitable type and voltage rating, or by automatic circuit
breakers of suitable type and rating. Where fuse protection is
provided, a disconnecting means shall be installed to disconnect
the fuses from the ungrounded service conductors.
SUBSTANTIATION: The proposed revision uses the term "surge
arresters" and.references Article 280 which covers the
selection, installation, and connection of surge arresters. A
CNP 5 Subcommittee has submitted proposals to update Article 280
to current nomenclature and ~ractices.
The grounding
connections for surge arresters are adequately covered in
Article 280 so i t is unnecessary to cover thegrounding
interconnections again in Section 502-3.
The third paragraph in the present text of Section 502-3 is
not enforceable and shouldbe deleted.
The present text requires circuit protection devices for
surge-protective capacitors.
I f fuses are used, a means should
be provided to disconnect the fuses and capacitors.
I t is
recommended that CMP 14 review the requirement that fuses by
exactly 30 amperes while circuit breakers have no specified
current rating.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative."
502-4(b): Reject
CMP 14
SUBMITTER: James M. Daly~ The Okonite~Co.
53 Revise as follows: " . . . or Type MI, MC, SNM,
i5"CTC-, or MV cable with approved termination f i t t i n g s shall be
the wiring method employed. Type MI, MC, SNM, PLTC, or MI/ cable
shall be permitted to be installed in cable tray systems and
shall be installed in a manner to avoid tensile stress at t h e
termination f i t t i n g s . "
,
SUBSTANTIATION: These cable types are permitted in Class I ,
Division 2 locations and i t is consistent to also permit their
use in Class I I , Division 2 locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Cable trays are dust collectors and should not ,
be used in Clas~ I I areas. NotePanel's action on Proposal No.'
51A.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502:5: Accept,'
CMP 14
Secretary's Note: I t was the action of the Correlating
Co{~nittee that further consideration be given to the comments
expressed in Mr. Schramts voting.
SUBMITTER:' G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 54 Delete Section 502-5.
~IATION:
In Class I I , Division i Iocatiohs i t is
necessary that motors be adequately sealed in the terminal box
and equipment is designed to be dust-tight. In.Class I I ,
Division 2 locations dust is normally not in suspension. I t is
my understanding that there have been some problems with
vertical or horizontal runs that may be just short of the
requi~ed length. Dust unlike vapors does not travel within the
conduit and does not offer a serious problem.
PANEL RECOMMENDATION: Accept as Revised:
"Where a raceway provides communication between an enclosdre
;that is required to be dust ignition proof and an enclosure in
l:an unclassified locat#on, seals will not be required."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
COMMENTON VOTE:
SCHRAM: The Panel Recommendation is not clear. My notes
indicate i t was to add the quoted paragraph to Section 502-5.
236
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 502 -- CLASS I I LOCATIONS
502-4: Accept
CMP 14
SUBMITTER: CMP 14
PITOI}O
' -~TAL-~: 51A Revise second sentence to read: "Cable tray
I ~ t
be permitted in Class I f , Division 1 or 2 locations.
SUBSTANTIATION: Cable trays are dust collectors and should not
be used in Class I I areas. •
PANEL RECOMMENDATION: Accept as Revised:
"Tray" should read "trays."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-I: Reject
CMP 14
SUBMITTER: G. A. Karstens, American, Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 48 " After the third paragraph add a paragraph as
502-4(a): Reject
CMP 14
SUBMITTER: K. C. Starkey, The Rockbestos Co.
52 Revise f i r s t sentence of (a) as follows:
In Class I f , Division 1 Iocatidns, threaded rigid metal
conduit, threaded steel intermediate metal conduit, Type MI, or
Type MC cable employing a continuous smooth or corrugated
aluminum sheath with termination f i t t i n g s approved for the
location shall be the wiring method employed.
SUBSTANTIATION: Type MC cable employing a continuous smooth or
corrugated aluminum sheath has a tight f i t t i n g core and is
sheathed in an impervious aluminum tube that has superior crush
and impact resistance.
I t has been used widely in Class I,
Division 2 and Class I I , Division 2 locations by the petroleu M,
petrochemical, coal and grain industries. Present continuous
welding methods make i t possible to maintain the accurate OD of
the cable sheath within the UL Standard 886 for maximum
diametric clearance for cylindrical joints. In earlier
manufacturing processes this was not possible; therefore, the
termination f i t t i n g manufacturers could not properly design a
termination f i t t i n g with prope~ barrel length and clearance to
comply with the UL Standards.
Termination f i t t i n g manufacturers, including Crouse-Hinds,
have assured us that i f the sheath OD can be held constant, a
termination f i t t i n g can be designed to comply with UL Standards.
The acceptance of Type MC cable employing a smooth or
corrugated aluminum sheath for use in Class I I , Division i
locations will provide "an alternate wiring system that is saYe
and economical to install. The sheath provides a completely
impervious tube from connection to ~onnection and with approved
termination f i t t i n g s Will eliminate the possibility of dusts
entering the system through joints and couplings.
We are submitting the following UL Test Reports* relative to
the physical properties of continuous aluminum sheathed Type MC
cable including impact, crushing, flexing and dielectric
withstand;
*Reports have been-supplied to CMP.chairman.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The Panel does not ~gree with the supporting
comment.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
For further information see NFPA496 Purged and Pressurized
Enclosures for Electrical Equip~mnt - 1974.
SUBSTANTIATION: Material in this bulletin will aid materially
in describing the proper requirements for motor control centers
for Class I I locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMEN~: Already covered by Section 500-I.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-i: Accept
CMP 14
Secretary's Note:. I t was the action of the Correlating
Committee that the Panel shall .review their Recommendation with
a view towards correcting grammatical errors.
SUBMITTER: W.A. Short, Crouse-Hinds Company
49 Add a new sentence to the end of 502-1:
--~r~-e-Fe-are only Division 1 locations where Class I I , Groups E
and F dusts are present. See Section 500-5(a)3.
SUBSTANTIATION: The information in 500-5(a)3 is not well
understood in the industry. This wording does not change the
intent, but helps to c l a r i f y the information already in the Code.
PANEL RECOMMENDATION: Accept as Revised:
After "dusts" add "having a r e s i s t i v i t y less than 105
ohm-cm."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-2(b)(3)(2): Accept
CMP 14
SUBMITTER: TSC-Nominal Voltage
50 Add "nominal" after "600 volts."
~O~-S~I~NTIATION: To conform'to the guidelines established by the
TSC on Nominal Voltages.
PANEL RECOMMENDATION: Accept.
PANEL COMMENT: See Panel Comment on Proposal 25.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
502-3: Accept
j
CMP 14
SUBMITTER: Robert'B. West, St. Louis, MO
PROPOSAL: 51 Revise as follows:
T-3.
Surge,Protection, Class I I , Divisions I and 2. In
geographical locations where lightning disturbances are
prevalent, and where supplied by overhead services, electric
systems in Class I I locations shall be protected against
high-voltage surges. This protection shall include surge
arresters, interconnectlon of all grounds, and surge-protective
capacitors.
Surge arresters, including their installation and
connections, shall comply with Article 280.
Surge-protective capacitors shall be of a type designed for
the specific duty. The capacitor grounding conductors shall be
connected to the grounding ~onductors for the surge arresters.
Surge-protective capacitors" shall be connected to each
ungrounded service conductor at the service entrance or service
equipment. The capacitors shall be protected by 30-ampere fuses
of suitable type and voltage rating, or by automatic circuit
breakers of suitable type and rating. Where fuse protection is
provided, a disconnecting means shall be installed to disconnect
the fuses from the ungrounded service conductors.
SUBSTANTIATION: The proposed revision uses the term "surge
arresters" and.references Article 280 which covers the
selection, installation, and connection of surge arresters. A
CNP 5 Subcommittee has submitted proposals to update Article 280
to current nomenclature and ~ractices.
The grounding
connections for surge arresters are adequately covered in
Article 280 so i t is unnecessary to cover thegrounding
interconnections again in Section 502-3.
The third paragraph in the present text of Section 502-3 is
not enforceable and shouldbe deleted.
The present text requires circuit protection devices for
surge-protective capacitors.
I f fuses are used, a means should
be provided to disconnect the fuses and capacitors.
I t is
recommended that CMP 14 review the requirement that fuses by
exactly 30 amperes while circuit breakers have no specified
current rating.
PANEL RECOMMENDATION: Accept.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative."
502-4(b): Reject
CMP 14
SUBMITTER: James M. Daly~ The Okonite~Co.
53 Revise as follows: " . . . or Type MI, MC, SNM,
i5"CTC-, or MV cable with approved termination f i t t i n g s shall be
the wiring method employed. Type MI, MC, SNM, PLTC, or MI/ cable
shall be permitted to be installed in cable tray systems and
shall be installed in a manner to avoid tensile stress at t h e
termination f i t t i n g s . "
,
SUBSTANTIATION: These cable types are permitted in Class I ,
Division 2 locations and i t is consistent to also permit their
use in Class I I , Division 2 locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Cable trays are dust collectors and should not ,
be used in Clas~ I I areas. NotePanel's action on Proposal No.'
51A.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502:5: Accept,'
CMP 14
Secretary's Note: I t was the action of the Correlating
Co{~nittee that further consideration be given to the comments
expressed in Mr. Schramts voting.
SUBMITTER:' G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 54 Delete Section 502-5.
~IATION:
In Class I I , Division i Iocatiohs i t is
necessary that motors be adequately sealed in the terminal box
and equipment is designed to be dust-tight. In.Class I I ,
Division 2 locations dust is normally not in suspension. I t is
my understanding that there have been some problems with
vertical or horizontal runs that may be just short of the
requi~ed length. Dust unlike vapors does not travel within the
conduit and does not offer a serious problem.
PANEL RECOMMENDATION: Accept as Revised:
"Where a raceway provides communication between an enclosdre
;that is required to be dust ignition proof and an enclosure in
l:an unclassified locat#on, seals will not be required."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
COMMENTON VOTE:
SCHRAM: The Panel Recommendation is not clear. My notes
indicate i t was to add the quoted paragraph to Section 502-5.
236
502-6(b): Accept
CMP 14
SUBMITTER: G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 55 Revise (b) as follows:
~ s s
I f , Division 2 locations, enclosures for fuses,
switches, circuit breakers, and motor controllers, including
pushbuttons, relays and similar devices shall be so designed
that: (1) there are no knockout holes provided in the
enclosure, (2) be constructed of substantial sheet metal with
continuous welded seams, (3) be gasketed with closed cell
expanded cellular rubber gasket of the oil/flame resistant type,
(4) where dust-tight mechanisms are involved they shall be
mounted through holes that are gasketed with a closed cell
expanded cellular rubber gasket of the oil/flame resistant type,
(5) doors shall be similarly gasketed, and where hinged shall be
hinged for horizontal opening and be supplied with an external
fastener that requires a tool to open, (6) provisions shall be
made for external mounting.
SUBSTANTIATION: The above wording provides a much clearer
understanding of the intent of the enclosures for fuses,
switches, circuit breakers,and motor controllers including
pushbuttons and relays and similar devices to be used in Class
I I , Division 2 locations than that used i'n 502-6(a)(2) in the
present Code.
*See proposals for Sections 502-7(b)(I) and 502-I0(b)(3).
PANEL RECOMMENDATION: Accept as revised:
In the third line substitute the word "dust tight" for the
'balance of the paragraph after the words "shall be."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-10(b)(3): Accept
CiMP 14
SUBMITTER: G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J..
Healy, Grain Elevator and Processing Society
PROPOSAL: 58 Delete the reference "Section 502-6(a)(2)" and
~ w i t h
"Section 502-6(b).
SUBSTANTIATION: The above wording provides a much clearer
understanding of the intent of the enclosures for fuses,
switches, circuit breakers and motor controllers including
pushbuttons and relays and similar devices to be used in Class
I I , Division 2 locations than that used in 502-6(a)(2) in the
present Code.
*See proposals for Sections 502-6(b) and 502-7(b)(I).
PANEL RECOMMENDATION: Accept as .Revised:
'
Replace the words "comply with Section 502-6(a)(2)" with "be
idust tight .
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-7(b)(I): Accept
CMP 14
SUBMITTER: G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 56 Delete the reference, "Section 502-6(a)(2)" and
~with
"Section 502-6(b)."
SUBSTANTIATION: The above wording provides a much clearer
understanding of the intent of the enclosures for fuses,
switches, circuit breakers and motor controllers including
pushbuttons and relays and similar devices to be used in Class
I I , Division 2 locations than that used in 502-6(a)(2) in the
present Code.
*See proposals for Sections 502-6(b) and 502-10(b)(3).
PANEL RECOMMENDATION: Accept as Revised:
I Revise Section 502-7(b)(1) to read: Switching mechanisms
(including,overcurrent devices) associated with control
transformers, solenoids, impedance coils, and resistors shall be
provided with dust-tight enclosures.
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
502-11(a)(4): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
I~-R'O-P-O-S~-~.'60 See the Technical Subcommittee "Reco~nmendations"
~ e
definition of "Approved for .the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Articl e I00.
I PANELRECOMMENDATION: Accept as Revised:
In line 2 delete "for the purpose and."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
502-11(a)(3): Accept
CMP 14
SUBMII'TER: TSC-Approvedfor the Purpose
~ 5 9
See the Technical Subcammittee'"Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article i00.r
PANEL REC~NDATION: Accept as Revised:
lq line 7 delete for the purpose and."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
592-11(b)(4): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
PITOP'o-SrAl_-~.'61 See the TechniCal Subcommittee "Recommendations"
~ e
definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I In line 7 add "an approved" before " f i t t i n g " and delete
"approved for the purpose."
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
.
502-8(b): Accept
CMP 14
SUBMITTER: G. A. Karstens, American Feed Manufacturers
~ o n ,
F. Lindholm, Association of Operative Millers, J.
Healy, Grain Elevator and Processing Society
PROPOSAL: 57 Revise (b) as follows:
-'-IL'l~-~-II, Division 2. In Class I I , Division 2 locations,
motors, generators and other rotating electrical equipment shall
be t o t a l l y enclosed non-ventilated, totally encl'osed pipe
ventilated, or totally enclosed fan cooled for w~ich maximum
f u l l load external surface temperature shall not exceed 120°C
(248°F) when operating in free air (not dust blanketed).
SUBSTANTIATION: We have found in many instances that various
authorities are of the opinion that the only motor suitable for
Class I I , Division 2 locations with the wording of Section
502-8(b) as is would be a labeled motor. I t is our contention
that labeled motors are not required for use in Class I I ,
Division 2 atmospheres, and the above wording is intended to
note such. In addition, experience of the industry over many
• years denotes that the TEFC motor has operated in Class I I ,
Division 2 locations with good experience.
PANEL RECOMMENDATION: Accept as Revised:
"Class I f , Division 2. In Class I I , Division 2 locations,
motors, generators and other rotating electrical equipment shall
be totally enclosed nonventilated, t o t a l l y enclosed pipe
ventilated, t o t a l l y enclosed fan cooled or dust-ignition-proof
for which maximum f u l l load external temperature shall not
exceed 120°C (248°F) when operating in free air (not dust
blanketed) and shall have no external openings.
Change Exception (b) to read: "...within dust-tight metal
housings..."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
COMMENTON VOTE:
ADAMS: My notes have the Exception to read: "...within
dust-tight housings."
SHORT: The Wording here is a marked improvement over that
presently in 1978 NEC. However, further improvement will be
achieved bythe ~ollowing revisions:
(1) Add the following sentence after the words "...and shall
have no external openings...": "Normally arcing or sparking
parts shall be enclosed in tight metal housings."
(2) In Exception (b) the present 1978 NEC wording "tight
metal housings" should be retained instead of changing to
"dust-tight housings."
/
502-11(b)(5): Accept
CMP 14
SUBMII-TER: TSC-Approvedfor the Purpose
~-RO
' -FO-~-A[-~: 62 See the Technical Subcommittee "Recommendations"
un--n-de~-~ITe definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
l'Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I} Delete paragraph and renumber (6) to (5).
'PANEL COMMENT: This paragraph does not seam to provide any
specific hazardous location requirements. General requirements
for support of light fixtures appear elsewhere in the Code.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-16(b): Reject
CMP 14
SUBMITTER: Joseph S.'Dudor, Fluor Engineers and Constructors,
PROPOSAL: 63 Revise last sentence as follows:
flexible conduit is used as permitted in Section 502-4,
internal or external bonding jumpers with proper f i t t i n g s shall
be provided.
SUBSTANTIATION: Revise Section 502-16(b) to have language
consistent with revision made to Section 501-16(b) in the 1978
NEC. The same problem and the samematerials are used in
applications in both Class I and Class I I locations andrthe Code
rules governing their use should be the same where possible.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: Covered by Proposal No. 64.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-16(b): Accept
CMP 14
SUBMI1-TER: Robert B. West, St. Louis, MO
I~qTOITO-SA
' t-~
•. 64 Revise the last sentence as follows:
l--I~h-e'~e--flexible conduit is used as permitted in Section 502-4,
237
/
internal or external bonding jumpers complying with the
provisions of Section 250-79 shall be installed parallel with
the conduit.
And add a fine print note as follows:
See Section 250-78.
SUBSTANTIATION: The requirements for flexible conduit bonding
jumpers should be the same in Sections 501-16(b) and 502-16(b).
The proposed rewording is consistent with my proposal to revise
the last sentence in 501-16(b).
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Adams.
EXPLANATION OF VOTE:
ADAMS: I do not believe the proposed revision adds to the
clarity of this section.
/
grounding electrode at the transformer supplying the service.
(2) A grounding conductor shall be run with the service
conductors from the supply transformer to the service equipment,
and shall be sized in accordance with the requirements for
sizing the grounded service conductor in Section 250-23(b). The
grounding conducto~ shall be bonded to the grounded service
conductor at the transformer supplying the service, and to the
equipment grounding conductor(s) at the service equipment.
(3) The service equipment enclosures, the grounding
conductor specified in (2) above, and the equipment grounding
conductor(s) shall be bonded together and connected to a
grounding electrode by a grounding electrode conductor.
SUBSTANTIATION: Objectional currents over the grounding
conductors are caused by multiple grounding connections to the
system grounded conductor, which is the grounded service
conductor in Section 502-16(d). One way to prevent these
objectional currents from flowing is to ground the grounded
service conductor at the supply transformer only, and abandon
the grounding connections to the grounded service conductor that
are specified in Sections 250-23(a), 250-50(a), and 250-53.
I t is perfectly safe to ground the grounded service conductor
at the supply transformer only, provided the conditions stated
in (2) and (3) of the proposed revis!on are met. These
conditions assure an adequate conductor for ground-fault current
to flow from the service equipment to the supply transformer and
the potential between the service equipment enclosures and
ground will not be unsafe during ground-fault conditions. The
surge protection that is specified in Section 502-3 provides
additional protection at the service equipment by limiting
voltages due to lightning and line surges. .
The present wording of Section 502-16(f) requires the grounded
service conductor to be grounded at the service .equipment i f the
supply system is grounded at any other point. This multiple
system grounding requirement is likely to cause obJectional
current over the grounding conductors i f the service conductors
are installed in metal raceways from the service supply to the
service equipment.
This proposal correlates with my proposal to revise Section
502-16(d).
PANEL RECOI~ENDATION: Accept as Revised:
• The t i t l e of this Sectionwill be "Multiple Grounds." In
order to correlate with Proposal Nos. 65, 66 and 67~ the number
of this Section w i l l be 502-16(d). Change (d) to (c) in the
f i r s t sentence oF the Proposal t o correlate with Proposal Nos.
65 and 66.
VOTE ON PANELRECOI~MENDATION: UnanimouslyAffirmative.
502-16(c): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, MO
~
i R-O-~O-S~AL-~
•. 65 Delete Section 502-16(c)
"S~]I~'TAI~TIATION: This section is unnecessary because lightning
protection in Class I I locations is adequately covered in
Section 502-3.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-16(d): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, MO
PF
' R-O-~O
' -SA
' -L-~.6
' 6 Revise as follows:
~rounded
Service Conductor, Connections at Service
Equipment. Where a Class I I location is supplied from an
alternating-current service and the supply system is solidly
grounded, the grounded service conductor shall be run to each
service according to the requirements in Section 250-23(b) and
shall be grounded according to the requirements in Section
250-23(a). Bonding connections to the grounded service
conductor at the service equipment shall comply with Sections
250-50(a) and 250-53. Metal enclosures for service conductors
and service equipment shall be bonded in accordance with the
applicable provisions in Article 250, Part G.
Exception: Where the installation complies with all of the
conditions specified in Section 502-16(f) and the system
grounded conductor is not used as a circui~ conductor, a
grounded service conductor shall not be required to be run to
the service equipment.
SUBSTANTIATION: This proposed revision correlates with my
proposal to revise the text of Section 502-16(f). The proposed
rewording and the references to sections in Article 250
clarifies the intent of Section 502-16(d) because the referenced
sections contain complete specifications for the general
requirements that are covered in the present text. The proposed
revision does not change the intent of the present text.
PANEL RECOMMENDATION: Accept as Revised.
Change the Section number to 502-16(c) to correlate with
iProposal 65, and change 502-16(f) in the Exception to 502-16(d)
to correlate with Proposal Nos. 67 and 68.
VOTE ON PANELRECOMMENDATION: UnanimouslyAffirmative.
502-17-(New): Reject
CMP 14
SUBMITTER: KennethL. Paape, Allen Bradley Co.
PITOIIO'~L-~.
• 69 Add new section as follows:
~'O-'~I'/~'-.Ground-Fault Protection of Equipment, Class I,
Divisions I and 2.
(a) Ground-fault protection shall be provided for each
solidly grounded branch circuit where conductors are not
protected against overcurrent in accordance with their
ampacities and the circuit is rated more than 50 volts to
ground, but exceeding 600 volts phase-to-phase in a Class I,
Division 1 or 2 location. The ground-fault protection shall
operate to open all ungrounded conductors of the faulted
circuit. The maximum setting of the ground-fault protection
shall be 10 amperes. Any time-delay in the operation of the
ground-fault protection shall" be coordinated with the
interrupting rating of the branch-circuit disconnecting or
controlling means and the rating or setting of the device that
provides overcurrent protection for the branch circuit.
Exception No. i: Where the circuit overcurrent protective
device has a rating or setting not exceeding 100 an~oeres.
Exception No. 2: Where an orderly shutdown is required. (See
Section 240-12.)
(b) The ground-fault protection system installed shall meet
the performance requirements of Section 230-95 (b) and (c).
SUBSTANTIATION I t has long been recognized in the electrical
industry that arcing ground faults occur which damage equipment
extensively because the ground fault current is limited by the
impedance of rigid conduit or is not sustained for a sufficient
period of time to cause the overcurrent protective device to
clear the fault. As a consequence, damage such as shown in the
attached photograph can occur with the emission of sparks and
molten metal. Such emission can ignite vapors or gases which
may be present in Class I Hazardous Locations. The higher the
rating Or setting of the overcurrent protective device the
greater the probability of extensive damagebefore the
overcurrent protective device responds to the ground-fault
current.
Each of the exceptions to the general rule of protecting
conductors against overcurrent in accordance with their
ampacities (See Section 240-3) exists for a good purpose, but
involves some degree of risk. Motor branch circuits are
particularly vulnerable because motor driven equipment often
includes a source of vibration which in turn can cause
insulation to abrade in conduit with the results as shown in the
photograph. Providing ground-fault protection for equipment in
such situations will reduce the risk inherent in circuits where
conductors are not protected in accordance with their an~)acities..
Similar proposals have been sub(nitted for Class I I and Class
I l l hazardous locations.
502-16(e): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, MO
67 DelebeSection 502-16(e)
~'I]I~'FAI~rIATION: The grounded service conductor of a grounded
system is required to be run to each service by the provisions
of Section 250-23(b), so the condition stated in Section
502-16(e) is not permitted. Article 250 also contains adequate
provisions for grounding and bonding that apply to Class I I
locations. For example, Section 250-23(a) requires the grounded
service conductor to be grounded at each service. Sections
250-50(a), 250-50(b), 2SO-53(a), and 250-53(b) cover bonding and
interconnections between the equipment grounding conductors, the
grounded service conductor, the grounding electrode conductor,
and the serviceequipment enclosures. Sections 250-71, 250-72,
250-75, 250-76, 250-77, 250-78, and 250-79 cover bonding
requirements for the noncurrent-carrying metal parts of
equipment, raceways and other enclosures on the supply side and
on the load'side of the service equipment.
My proposed revision for Section 502-16[f) covers conditions
which must be complied with where a grounded service conductor
of a grounded system is not run to the service equipment.
PANEL RECOMMENDATION: Accept.
VOTE ON PANELRECOMMENDATION: UnanimouslyA f f i r m a t i v e . .
502-16(f): Accept
CMP 14
SUBMITTER: Robert B. West, St. Louis, MO
. ~
68 Revise the text of (f) as follows:
Where, in the application of Section 250-21, i t is necessary
to abandon ~he grounding and bonding connections to the grounded
service conductor that are specified in (d) above, the
installation shall comply with all of the following conditions:
(I) The grounded service conductor shall be connected to a
238
ARTICLE 511 -- COMMERCIALGARAGES, REPAIR AND STORAGE
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
511-2(f): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
PITOPI~SAL-~: 73
See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article lOO.
PANEL RECOMMENDATION: Accept as Revised:
I In line 7 insert "suitable" between "other" and "material"
delete "approved for the purpose."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 503 -- CLASS I l l LOCATIONS
503-9(c)~ Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
70 See the Technical Subcommittee "Recommendations"
un-u-~-d~-~-]~e definition of "Approved for the Purpose" =in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definiti'on of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I In line 6 insert "an approved" before " f i t t i n g " delete
"approved for the purpose."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
.ARTICLE 513 -- AIRCRAFT HANGARS
513-5(c): Accept
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
74 Delete the words "that are or may be."
SUBSTANTIATION: The use of the words "or may be" renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
,*See Border County Div. IAEI substantiation for CMP 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Accept as Revised:
"Portable lamps that are used within a hangar shall be
approved for the location in which they are used."
PANEL COMMENT: Panel recommends review of Section 513-5 by N~PA
Committee 409, basically to review use of portable equipment in
hangars
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
503-9(d): Acce~t
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
71
See the Technical Subcommittee "Recommendations"
un'un-d-er-tF1e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete paragraph and change (e) to (d).
PANEL COMMENT: This paragraph does not seem to provide any
specific hazardous location requirements. General requirements
for support of light fixtures appear elsewhere in the Code.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-8: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
~ 7 5
Delete 513-8.
S~IATION:
This section is practically unenforceable
unless the jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed'change.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
503-17-iNew): Reject
'
,~/
CMP 14
SUBMITTER: Kenneth L. Paape, ellen Bradley Co.
72 Add new section as follows:
5--0-3--Z17~- . Ground-Fault Protection of Equipment, Class I l l ,
Divisions i and 2.
(a) Ground-fault protection shall be provided for each
solidly grounded branch circuit where conductors are not
protected against overcurrent in accordance with their
ampacities and the circuit is rated more than 50 volts to
ground, but exceeding 600 volts phase-to-phase in a Class I l l ,
Division 1 or 2 location. The ground-fault protection ~hall
operate to open all ungrounded conductors of the faulted
circuit. The maximum setting of the ground-fault protection
shall be 10 amperes. Any time-delay in the operation of the
ground-fault protection shall be coordinated with the
interrupting rating of the branch-circuit disconnecting or
controlling means and the rating or setting of the device that
provides overcurrent protection for the branch c i r c u i t .
Exception No. I : Where the circuit overcurrent protective
device has a rating or setting not exceeding 100 amperes.
Exception No. 2.: Where an orderly shutdowd is required.
(See Section 240-12).
501-17-(New)
(b) The ground-fault protection system installed shall meet
the performance requirements of Section 230-95 (b) and (c).
SUBSTANTIATION I t has long been recognized in the electrical
industry that arcing ground faults occur which damage equipment
extensively because the ground fault current is limited by the
impedance of rigid conduit or is not sustained for a sufficient
period of time to cause the overcurrent protective device to
clear the fault. As a consequence, damage such as shown in the
attached photograph can occur with the emission of sparks and
molten metal. Such emission can ignite fibers or flyers which
may be present in Class I l l Hazardous Locations. The higher the
rating or setting of the overcurrent protective device the
gPeater the probability of extensive damage before the
overcurrent protective device responds to the ground-fault
current.
Each of the exceptions to the general rule of protecting
conductors against overcurrent in accordance with their
ampacities (see Section 240-3) exists for a good purpose, but
involves somedegree of risk. Motor branch circuits are
particularly vulnerable because motor driven equipment often
includes a source of vibration which in turn can cause
insulation to abrade in conduit with the results as shown in the
photograph. Providing ground-fault protection for equipment in
such situations will reduce the risk inherent in circuits where
conductors are not protected in accordance with their ampacities.
Similar proposals have been submitted for Class I and Class I I
hazardous locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the '
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-9: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
76 Delete 513-9.
~IATION:
This section is practically unenforceable
unless the Jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. go for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting c~Tfnent does not j u s t i f y the •
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
ARTICLE 514 -- GASOLINE DISPENSINGAND SERVICE STATIONS~°
514-2: Accept
CMP 14
SUBMITTER: EdwardC. Sommer NFPA No. 30 S/C General Storage
~ o m b .
Liquids
PROPOSAL: 77 Delete Section 514-2(a) through (g) andreplace
following:'
The following table shall be applied where Class I liquids are
stored, handled or dispensed and shall be used to delineate and
classify service station areas for the purpose of electrical
equipment under normal circumstances. I t is based on the
premise that the installation meets all requirements of NFPA No.
30. Should this not be the case, the inspector shall have the
authority to determine the extent of the classified area. A
classified area shall not extend beyond an unpierced wall, roof
or other solid partition.
SUBSTANTIATION: NFPANo. 30 S/C General Storage and Handling of
Flammable and Combustible Liquids has the basic responsibility
for classification of electrical areas in service stations. The
present text in No. 70 is not in complete agreement with No. 30
and thus presents a conflict. This can be eliminated by:
(1) Revision of the existing test in No. 70, or (2) by
dropping requirements contained in these articles and
referencing No. 30, or (3) by incorporating the table contained
in No. 30 into 514-2 of No. 70.
Of the three approaches, number 3 is probably the most
attractive since i t eliminates the conflict and provides
information to the inspector without the need for an additional
reference code. Updating as changes may be made in No. 30 is
not a significant problem sinceboth codes are close in cycles.
239
ARTICLE 511 -- COMMERCIALGARAGES, REPAIR AND STORAGE
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
511-2(f): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
PITOPI~SAL-~: 73
See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article lOO.
PANEL RECOMMENDATION: Accept as Revised:
I In line 7 insert "suitable" between "other" and "material"
delete "approved for the purpose."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 503 -- CLASS I l l LOCATIONS
503-9(c)~ Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
70 See the Technical Subcommittee "Recommendations"
un-u-~-d~-~-]~e definition of "Approved for the Purpose" =in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definiti'on of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I In line 6 insert "an approved" before " f i t t i n g " delete
"approved for the purpose."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
.ARTICLE 513 -- AIRCRAFT HANGARS
513-5(c): Accept
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
74 Delete the words "that are or may be."
SUBSTANTIATION: The use of the words "or may be" renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
,*See Border County Div. IAEI substantiation for CMP 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Accept as Revised:
"Portable lamps that are used within a hangar shall be
approved for the location in which they are used."
PANEL COMMENT: Panel recommends review of Section 513-5 by N~PA
Committee 409, basically to review use of portable equipment in
hangars
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
503-9(d): Acce~t
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
71
See the Technical Subcommittee "Recommendations"
un'un-d-er-tF1e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete paragraph and change (e) to (d).
PANEL COMMENT: This paragraph does not seem to provide any
specific hazardous location requirements. General requirements
for support of light fixtures appear elsewhere in the Code.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-8: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
~ 7 5
Delete 513-8.
S~IATION:
This section is practically unenforceable
unless the jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed'change.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
503-17-iNew): Reject
'
,~/
CMP 14
SUBMITTER: Kenneth L. Paape, ellen Bradley Co.
72 Add new section as follows:
5--0-3--Z17~- . Ground-Fault Protection of Equipment, Class I l l ,
Divisions i and 2.
(a) Ground-fault protection shall be provided for each
solidly grounded branch circuit where conductors are not
protected against overcurrent in accordance with their
ampacities and the circuit is rated more than 50 volts to
ground, but exceeding 600 volts phase-to-phase in a Class I l l ,
Division 1 or 2 location. The ground-fault protection ~hall
operate to open all ungrounded conductors of the faulted
circuit. The maximum setting of the ground-fault protection
shall be 10 amperes. Any time-delay in the operation of the
ground-fault protection shall be coordinated with the
interrupting rating of the branch-circuit disconnecting or
controlling means and the rating or setting of the device that
provides overcurrent protection for the branch c i r c u i t .
Exception No. I : Where the circuit overcurrent protective
device has a rating or setting not exceeding 100 amperes.
Exception No. 2.: Where an orderly shutdowd is required.
(See Section 240-12).
501-17-(New)
(b) The ground-fault protection system installed shall meet
the performance requirements of Section 230-95 (b) and (c).
SUBSTANTIATION I t has long been recognized in the electrical
industry that arcing ground faults occur which damage equipment
extensively because the ground fault current is limited by the
impedance of rigid conduit or is not sustained for a sufficient
period of time to cause the overcurrent protective device to
clear the fault. As a consequence, damage such as shown in the
attached photograph can occur with the emission of sparks and
molten metal. Such emission can ignite fibers or flyers which
may be present in Class I l l Hazardous Locations. The higher the
rating or setting of the overcurrent protective device the
gPeater the probability of extensive damage before the
overcurrent protective device responds to the ground-fault
current.
Each of the exceptions to the general rule of protecting
conductors against overcurrent in accordance with their
ampacities (see Section 240-3) exists for a good purpose, but
involves somedegree of risk. Motor branch circuits are
particularly vulnerable because motor driven equipment often
includes a source of vibration which in turn can cause
insulation to abrade in conduit with the results as shown in the
photograph. Providing ground-fault protection for equipment in
such situations will reduce the risk inherent in circuits where
conductors are not protected in accordance with their ampacities.
Similar proposals have been submitted for Class I and Class I I
hazardous locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the '
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-9: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
76 Delete 513-9.
~IATION:
This section is practically unenforceable
unless the Jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. go for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting c~Tfnent does not j u s t i f y the •
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
ARTICLE 514 -- GASOLINE DISPENSINGAND SERVICE STATIONS~°
514-2: Accept
CMP 14
SUBMITTER: EdwardC. Sommer NFPA No. 30 S/C General Storage
~ o m b .
Liquids
PROPOSAL: 77 Delete Section 514-2(a) through (g) andreplace
following:'
The following table shall be applied where Class I liquids are
stored, handled or dispensed and shall be used to delineate and
classify service station areas for the purpose of electrical
equipment under normal circumstances. I t is based on the
premise that the installation meets all requirements of NFPA No.
30. Should this not be the case, the inspector shall have the
authority to determine the extent of the classified area. A
classified area shall not extend beyond an unpierced wall, roof
or other solid partition.
SUBSTANTIATION: NFPANo. 30 S/C General Storage and Handling of
Flammable and Combustible Liquids has the basic responsibility
for classification of electrical areas in service stations. The
present text in No. 70 is not in complete agreement with No. 30
and thus presents a conflict. This can be eliminated by:
(1) Revision of the existing test in No. 70, or (2) by
dropping requirements contained in these articles and
referencing No. 30, or (3) by incorporating the table contained
in No. 30 into 514-2 of No. 70.
Of the three approaches, number 3 is probably the most
attractive since i t eliminates the conflict and provides
information to the inspector without the need for an additional
reference code. Updating as changes may be made in No. 30 is
not a significant problem sinceboth codes are close in cycles.
239
ARTICLE 511 -- COMMERCIALGARAGES, REPAIR AND STORAGE
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
511-2(f): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
PITOPI~SAL-~: 73
See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article lOO.
PANEL RECOMMENDATION: Accept as Revised:
I In line 7 insert "suitable" between "other" and "material"
delete "approved for the purpose."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 503 -- CLASS I l l LOCATIONS
503-9(c)~ Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
70 See the Technical Subcommittee "Recommendations"
un-u-~-d~-~-]~e definition of "Approved for the Purpose" =in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definiti'on of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I In line 6 insert "an approved" before " f i t t i n g " delete
"approved for the purpose."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
.ARTICLE 513 -- AIRCRAFT HANGARS
513-5(c): Accept
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
74 Delete the words "that are or may be."
SUBSTANTIATION: The use of the words "or may be" renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
,*See Border County Div. IAEI substantiation for CMP 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Accept as Revised:
"Portable lamps that are used within a hangar shall be
approved for the location in which they are used."
PANEL COMMENT: Panel recommends review of Section 513-5 by N~PA
Committee 409, basically to review use of portable equipment in
hangars
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
503-9(d): Acce~t
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
71
See the Technical Subcommittee "Recommendations"
un'un-d-er-tF1e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete paragraph and change (e) to (d).
PANEL COMMENT: This paragraph does not seem to provide any
specific hazardous location requirements. General requirements
for support of light fixtures appear elsewhere in the Code.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-8: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
~ 7 5
Delete 513-8.
S~IATION:
This section is practically unenforceable
unless the jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed'change.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
503-17-iNew): Reject
'
,~/
CMP 14
SUBMITTER: Kenneth L. Paape, ellen Bradley Co.
72 Add new section as follows:
5--0-3--Z17~- . Ground-Fault Protection of Equipment, Class I l l ,
Divisions i and 2.
(a) Ground-fault protection shall be provided for each
solidly grounded branch circuit where conductors are not
protected against overcurrent in accordance with their
ampacities and the circuit is rated more than 50 volts to
ground, but exceeding 600 volts phase-to-phase in a Class I l l ,
Division 1 or 2 location. The ground-fault protection ~hall
operate to open all ungrounded conductors of the faulted
circuit. The maximum setting of the ground-fault protection
shall be 10 amperes. Any time-delay in the operation of the
ground-fault protection shall be coordinated with the
interrupting rating of the branch-circuit disconnecting or
controlling means and the rating or setting of the device that
provides overcurrent protection for the branch c i r c u i t .
Exception No. I : Where the circuit overcurrent protective
device has a rating or setting not exceeding 100 amperes.
Exception No. 2.: Where an orderly shutdowd is required.
(See Section 240-12).
501-17-(New)
(b) The ground-fault protection system installed shall meet
the performance requirements of Section 230-95 (b) and (c).
SUBSTANTIATION I t has long been recognized in the electrical
industry that arcing ground faults occur which damage equipment
extensively because the ground fault current is limited by the
impedance of rigid conduit or is not sustained for a sufficient
period of time to cause the overcurrent protective device to
clear the fault. As a consequence, damage such as shown in the
attached photograph can occur with the emission of sparks and
molten metal. Such emission can ignite fibers or flyers which
may be present in Class I l l Hazardous Locations. The higher the
rating or setting of the overcurrent protective device the
gPeater the probability of extensive damage before the
overcurrent protective device responds to the ground-fault
current.
Each of the exceptions to the general rule of protecting
conductors against overcurrent in accordance with their
ampacities (see Section 240-3) exists for a good purpose, but
involves somedegree of risk. Motor branch circuits are
particularly vulnerable because motor driven equipment often
includes a source of vibration which in turn can cause
insulation to abrade in conduit with the results as shown in the
photograph. Providing ground-fault protection for equipment in
such situations will reduce the risk inherent in circuits where
conductors are not protected in accordance with their ampacities.
Similar proposals have been submitted for Class I and Class I I
hazardous locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the '
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-9: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
76 Delete 513-9.
~IATION:
This section is practically unenforceable
unless the Jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. go for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting c~Tfnent does not j u s t i f y the •
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
ARTICLE 514 -- GASOLINE DISPENSINGAND SERVICE STATIONS~°
514-2: Accept
CMP 14
SUBMITTER: EdwardC. Sommer NFPA No. 30 S/C General Storage
~ o m b .
Liquids
PROPOSAL: 77 Delete Section 514-2(a) through (g) andreplace
following:'
The following table shall be applied where Class I liquids are
stored, handled or dispensed and shall be used to delineate and
classify service station areas for the purpose of electrical
equipment under normal circumstances. I t is based on the
premise that the installation meets all requirements of NFPA No.
30. Should this not be the case, the inspector shall have the
authority to determine the extent of the classified area. A
classified area shall not extend beyond an unpierced wall, roof
or other solid partition.
SUBSTANTIATION: NFPANo. 30 S/C General Storage and Handling of
Flammable and Combustible Liquids has the basic responsibility
for classification of electrical areas in service stations. The
present text in No. 70 is not in complete agreement with No. 30
and thus presents a conflict. This can be eliminated by:
(1) Revision of the existing test in No. 70, or (2) by
dropping requirements contained in these articles and
referencing No. 30, or (3) by incorporating the table contained
in No. 30 into 514-2 of No. 70.
Of the three approaches, number 3 is probably the most
attractive since i t eliminates the conflict and provides
information to the inspector without the need for an additional
reference code. Updating as changes may be made in No. 30 is
not a significant problem sinceboth codes are close in cycles.
239
ARTICLE 511 -- COMMERCIALGARAGES, REPAIR AND STORAGE
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
511-2(f): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
PITOPI~SAL-~: 73
See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article lOO.
PANEL RECOMMENDATION: Accept as Revised:
I In line 7 insert "suitable" between "other" and "material"
delete "approved for the purpose."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 503 -- CLASS I l l LOCATIONS
503-9(c)~ Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
70 See the Technical Subcommittee "Recommendations"
un-u-~-d~-~-]~e definition of "Approved for the Purpose" =in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definiti'on of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I In line 6 insert "an approved" before " f i t t i n g " delete
"approved for the purpose."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
.ARTICLE 513 -- AIRCRAFT HANGARS
513-5(c): Accept
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
74 Delete the words "that are or may be."
SUBSTANTIATION: The use of the words "or may be" renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
,*See Border County Div. IAEI substantiation for CMP 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Accept as Revised:
"Portable lamps that are used within a hangar shall be
approved for the location in which they are used."
PANEL COMMENT: Panel recommends review of Section 513-5 by N~PA
Committee 409, basically to review use of portable equipment in
hangars
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
503-9(d): Acce~t
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
71
See the Technical Subcommittee "Recommendations"
un'un-d-er-tF1e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete paragraph and change (e) to (d).
PANEL COMMENT: This paragraph does not seem to provide any
specific hazardous location requirements. General requirements
for support of light fixtures appear elsewhere in the Code.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-8: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
~ 7 5
Delete 513-8.
S~IATION:
This section is practically unenforceable
unless the jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed'change.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
503-17-iNew): Reject
'
,~/
CMP 14
SUBMITTER: Kenneth L. Paape, ellen Bradley Co.
72 Add new section as follows:
5--0-3--Z17~- . Ground-Fault Protection of Equipment, Class I l l ,
Divisions i and 2.
(a) Ground-fault protection shall be provided for each
solidly grounded branch circuit where conductors are not
protected against overcurrent in accordance with their
ampacities and the circuit is rated more than 50 volts to
ground, but exceeding 600 volts phase-to-phase in a Class I l l ,
Division 1 or 2 location. The ground-fault protection ~hall
operate to open all ungrounded conductors of the faulted
circuit. The maximum setting of the ground-fault protection
shall be 10 amperes. Any time-delay in the operation of the
ground-fault protection shall be coordinated with the
interrupting rating of the branch-circuit disconnecting or
controlling means and the rating or setting of the device that
provides overcurrent protection for the branch c i r c u i t .
Exception No. I : Where the circuit overcurrent protective
device has a rating or setting not exceeding 100 amperes.
Exception No. 2.: Where an orderly shutdowd is required.
(See Section 240-12).
501-17-(New)
(b) The ground-fault protection system installed shall meet
the performance requirements of Section 230-95 (b) and (c).
SUBSTANTIATION I t has long been recognized in the electrical
industry that arcing ground faults occur which damage equipment
extensively because the ground fault current is limited by the
impedance of rigid conduit or is not sustained for a sufficient
period of time to cause the overcurrent protective device to
clear the fault. As a consequence, damage such as shown in the
attached photograph can occur with the emission of sparks and
molten metal. Such emission can ignite fibers or flyers which
may be present in Class I l l Hazardous Locations. The higher the
rating or setting of the overcurrent protective device the
gPeater the probability of extensive damage before the
overcurrent protective device responds to the ground-fault
current.
Each of the exceptions to the general rule of protecting
conductors against overcurrent in accordance with their
ampacities (see Section 240-3) exists for a good purpose, but
involves somedegree of risk. Motor branch circuits are
particularly vulnerable because motor driven equipment often
includes a source of vibration which in turn can cause
insulation to abrade in conduit with the results as shown in the
photograph. Providing ground-fault protection for equipment in
such situations will reduce the risk inherent in circuits where
conductors are not protected in accordance with their ampacities.
Similar proposals have been submitted for Class I and Class I I
hazardous locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the '
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-9: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
76 Delete 513-9.
~IATION:
This section is practically unenforceable
unless the Jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. go for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting c~Tfnent does not j u s t i f y the •
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
ARTICLE 514 -- GASOLINE DISPENSINGAND SERVICE STATIONS~°
514-2: Accept
CMP 14
SUBMITTER: EdwardC. Sommer NFPA No. 30 S/C General Storage
~ o m b .
Liquids
PROPOSAL: 77 Delete Section 514-2(a) through (g) andreplace
following:'
The following table shall be applied where Class I liquids are
stored, handled or dispensed and shall be used to delineate and
classify service station areas for the purpose of electrical
equipment under normal circumstances. I t is based on the
premise that the installation meets all requirements of NFPA No.
30. Should this not be the case, the inspector shall have the
authority to determine the extent of the classified area. A
classified area shall not extend beyond an unpierced wall, roof
or other solid partition.
SUBSTANTIATION: NFPANo. 30 S/C General Storage and Handling of
Flammable and Combustible Liquids has the basic responsibility
for classification of electrical areas in service stations. The
present text in No. 70 is not in complete agreement with No. 30
and thus presents a conflict. This can be eliminated by:
(1) Revision of the existing test in No. 70, or (2) by
dropping requirements contained in these articles and
referencing No. 30, or (3) by incorporating the table contained
in No. 30 into 514-2 of No. 70.
Of the three approaches, number 3 is probably the most
attractive since i t eliminates the conflict and provides
information to the inspector without the need for an additional
reference code. Updating as changes may be made in No. 30 is
not a significant problem sinceboth codes are close in cycles.
239
ARTICLE 511 -- COMMERCIALGARAGES, REPAIR AND STORAGE
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
511-2(f): Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
PITOPI~SAL-~: 73
See the Technical Subcommittee "Recommendations"
under the definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article lOO.
PANEL RECOMMENDATION: Accept as Revised:
I In line 7 insert "suitable" between "other" and "material"
delete "approved for the purpose."
VOTE ON PANELRECOMMENDATION: Unanimously Affirmative.
ARTICLE 503 -- CLASS I l l LOCATIONS
503-9(c)~ Accept
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
70 See the Technical Subcommittee "Recommendations"
un-u-~-d~-~-]~e definition of "Approved for the Purpose" =in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definiti'on of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I In line 6 insert "an approved" before " f i t t i n g " delete
"approved for the purpose."
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
.ARTICLE 513 -- AIRCRAFT HANGARS
513-5(c): Accept
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
74 Delete the words "that are or may be."
SUBSTANTIATION: The use of the words "or may be" renders this
section legally unenforceable. See the attached opinion* of the
San Diego City Attorney.
,*See Border County Div. IAEI substantiation for CMP 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Accept as Revised:
"Portable lamps that are used within a hangar shall be
approved for the location in which they are used."
PANEL COMMENT: Panel recommends review of Section 513-5 by N~PA
Committee 409, basically to review use of portable equipment in
hangars
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
503-9(d): Acce~t
CMP 14
SUBMITTER: TSC-Approvedfor the Purpose
71
See the Technical Subcommittee "Recommendations"
un'un-d-er-tF1e definition of "Approved for the Purpose" in Article
100.
SUBSTANTIATION: See the TSC "findings" under the definition of
"Approved for the Purpose" in Article 100.
PANEL RECOMMENDATION: Accept as Revised:
I Delete paragraph and change (e) to (d).
PANEL COMMENT: This paragraph does not seem to provide any
specific hazardous location requirements. General requirements
for support of light fixtures appear elsewhere in the Code.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-8: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
~ 7 5
Delete 513-8.
S~IATION:
This section is practically unenforceable
unless the jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. 90 for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the
proposed'change.
VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.
503-17-iNew): Reject
'
,~/
CMP 14
SUBMITTER: Kenneth L. Paape, ellen Bradley Co.
72 Add new section as follows:
5--0-3--Z17~- . Ground-Fault Protection of Equipment, Class I l l ,
Divisions i and 2.
(a) Ground-fault protection shall be provided for each
solidly grounded branch circuit where conductors are not
protected against overcurrent in accordance with their
ampacities and the circuit is rated more than 50 volts to
ground, but exceeding 600 volts phase-to-phase in a Class I l l ,
Division 1 or 2 location. The ground-fault protection ~hall
operate to open all ungrounded conductors of the faulted
circuit. The maximum setting of the ground-fault protection
shall be 10 amperes. Any time-delay in the operation of the
ground-fault protection shall be coordinated with the
interrupting rating of the branch-circuit disconnecting or
controlling means and the rating or setting of the device that
provides overcurrent protection for the branch c i r c u i t .
Exception No. I : Where the circuit overcurrent protective
device has a rating or setting not exceeding 100 amperes.
Exception No. 2.: Where an orderly shutdowd is required.
(See Section 240-12).
501-17-(New)
(b) The ground-fault protection system installed shall meet
the performance requirements of Section 230-95 (b) and (c).
SUBSTANTIATION I t has long been recognized in the electrical
industry that arcing ground faults occur which damage equipment
extensively because the ground fault current is limited by the
impedance of rigid conduit or is not sustained for a sufficient
period of time to cause the overcurrent protective device to
clear the fault. As a consequence, damage such as shown in the
attached photograph can occur with the emission of sparks and
molten metal. Such emission can ignite fibers or flyers which
may be present in Class I l l Hazardous Locations. The higher the
rating or setting of the overcurrent protective device the
gPeater the probability of extensive damage before the
overcurrent protective device responds to the ground-fault
current.
Each of the exceptions to the general rule of protecting
conductors against overcurrent in accordance with their
ampacities (see Section 240-3) exists for a good purpose, but
involves somedegree of risk. Motor branch circuits are
particularly vulnerable because motor driven equipment often
includes a source of vibration which in turn can cause
insulation to abrade in conduit with the results as shown in the
photograph. Providing ground-fault protection for equipment in
such situations will reduce the risk inherent in circuits where
conductors are not protected in accordance with their ampacities.
Similar proposals have been submitted for Class I and Class I I
hazardous locations.
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting comment does not j u s t i f y the '
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
513-9: Reject
CMP 14
SUBMITTER: O. E. Dillon, Border County Div. IAEI
76 Delete 513-9.
~IATION:
This section is practically unenforceable
unless the Jurisdiction has the man- power to make routine
inspection of aircraft in aircraft hangers. See the attached
opinion* of the San Diego City Attorney.
*See Border County Div. IAEI substantiation for C~ 1 Proposal
No. go for 110-16(a).
PANEL RECOMMENDATION: Reject.
PANEL COMMENT: The supporting c~Tfnent does not j u s t i f y the •
proposed change.
VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.
ARTICLE 514 -- GASOLINE DISPENSINGAND SERVICE STATIONS~°
514-2: Accept
CMP 14
SUBMITTER: EdwardC. Sommer NFPA No. 30 S/C General Storage
~ o m b .
Liquids
PROPOSAL: 77 Delete Section 514-2(a) through (g) andreplace
following:'
The following table shall be applied where Class I liquids are
stored, handled or dispensed and shall be used to delineate and
classify service station areas for the purpose of electrical
equipment under normal circumstances. I t is based on the
premise that the installation meets all requirements of NFPA No.
30. Should this not be the case, the inspector shall have the
authority to determine the extent of the classified area. A
classified area shall not extend beyond an unpierced wall, roof
or other solid partition.
SUBSTANTIATION: NFPANo. 30 S/C General Storage and Handling of
Flammable and Combustible Liquids has the basic responsibility
for classification of electrical areas in service stations. The
present text in No. 70 is not in complete agreement with No. 30
and thus presents a conflict. This can be eliminated by:
(1) Revision of the existing test in No. 70, or (2) by
dropping requirements contained in these articles and
referencing No. 30, or (3) by incorporating the table contained
in No. 30 into 514-2 of No. 70.
Of the three approaches, number 3 is probably the most
attractive since i t eliminates the conflict and provides
information to the inspector without the need for an additional
reference code. Updating as changes may be made in No. 30 is
not a significant problem sinceboth codes are close in cycles.
239
There is a further advantage since the table proposed for
inclusion in No. 70 is more complete and covers classified areas
n o t presently covered in No. 70.
"PANEL RECOMMENDATION: Accept as Revised:
I Substitute the words "The following table" with "Table
514-2". Incorporate Table 7-1 from NFPA30 into 514-2 of NFPA
70. (See enclosed editorial modifications.) In line 3 change
"station" to "stations" and delete remainder of Proposal.
VOTE ON PANELRECOMMENDATION:
AFFIRMATIVE: 16.
NEGATIVE: Adams. ,
COI~MENTON VOTE:
gWERS: The last sentence of the proposal should remain: "A
classified area shall not-extend beyond an unpierced wall, roof
or other solid partition." See write-up that was used at the
Denver meeting of CMP 14. See also the f i r s t paragraph of Panel
Recommendation on Proposal No. 87.
SCHRAM: My notes indicate the change in line 3 was to change
"service station areas" to "service stations."
EXPLANATION OF VOTE:
ADAMS: I think a better resolution of the differences between
NFPA 30 and this section would be a reference to NFPA 30 at this
point. I am opposed to copying other NFPA publications in the
NEC.
Table
514-2
Class I L o c a t i o n s
"-¢-~'
-Class
Group D
Divifion
Service
Stations
I,
;~,
Class I Location
UNDERGROUND TANK
Fill O p e n i n g
Any pit, box or space below
grade level, any part of which is
within thc Division I or 2 ,I __i
fiocation. •1
h
U p to 18 inches above grade
Icvcl within a horizontal radius
of 10 feet from ,a loose fill connection a n d within a horizontal
radius o f 5 feet from a fight fill
connection.
Vent-
Discharging U p w a r d
Within 3 feet of open e n d of
vent, e x t e n d i n g in all directions. ~
/Uat"-k~etween 3 feet a n d 5 feet
of open e n d of vent, extending in
all directions.
"
( ~pace I
DISPENSING UNITS
(except overhead type)
Pits
Dispenser
1
1
2
Any pit, box or space below
grade level, any p a r t of w h i c h is
within the Division 1 or 2 c ' . : - 2
The~within
a dispenser enclosure up to 4 feet vertically
above the base except that ...c-defined as Division 2. A n y . . . .
within a nozzle boot.
A m ~ f ' - w i t h i n a dispenser enclosure above the Division 1
~ i m m a ~ .p~.er
enclosure isolated from D,vision
1 by a solid partition or a solid
nozzle boot b u t n o t completely
s u r r o u n d e d by Division 1 ~
W i t h i n 18 inches horizontally in
all directions from the Division 1
at,ml'/~at~ect wlthtrr the mspenser
enclosure.
W i t h i n 18 inches horizontally in
all directions from~ the opening
of a nozzle boot not isolated by
a vapor-fight partition, excent
that the dassitled ~Nd--~nneed n~t
be e x t e n d e d a r o u n d a 90* o r
g r e a t e r corner.
a,,,.FA,,~
,
240
rlocation
I /.._~r'~_~..~
~cation.]
4Lbpacesj
|.~/ 0 c a t i 0 n l~10cati0~J
~ation
1
Table 514-2 --. continued
Class I,
Group D
Division
Location
Extent of
4m~Class
I Location
Up to 18 inches above grade
level within 20 feet horizontally
of any edge of enclosure.
Outdoor
INDOOR
Up to 18 inches above grade or
floor level within 20 feet horizontally of any edge of enclmure.
with Mechanical Ventilation
with Gravity Ventilation
Up to 18 inches above grade or
floor level within 25 feet horizontally of any edge of enclosure.
DISPENSINGUNITS~
Within the dispenser enclosure
and 18 inches in all directions
from the enclosure where not
suitably cut off by ceiling or
wall. All electrical equipment
integral with the dispensing hose
or nozzle.
O v z a ~ m ~ Tcp~
extending-- 2 feet horizontally in all directions beyond
the Division 1 * N d anna exfendhag to grade below this cJa~ifled
UI)
to 18 inches above grade
level within 20 feet horizontally
measured from a point vertically
below the ecl.ge of any dispenser
enclosure.
R~uo~g Puup - - C ~ o o R
1
Any pit, box or space below
grade level ff any part is within
a horizontal distance of 10 feet
from any edge of pump.
Within 3 feet of any edge of
pump, extending in all directions. Also up to 18 inches above
grade level within 10 feet horizontally from any edge of pump.
]~LlluOTg P u M P
Entire jmr'GTthin any pit.
-- INDOOR
Within 5 feet of any edge of
p.ump, extending in all direcuons. Also up to 3 feet above
floor or grade level within 25
feet horizontally from any edge
of pump.
241
IA space_]
- ~l ocationJ
~ocation.l
Tab