Question 1: Statement - I have been told that sawdust is not considered a combustible. I have
been in hardwood mills where hardwood dust is almost too fine to be handled by the dust
collector system. Question - Should these type plants be wired Class II, Division 1 or 2?
Panel Response: o
Question 2: Statement - The phrase “physical damage” is included in 184 locations throughout
the NEC. Physical damage is not defined in Article 100 and based on the requirements included
in those 184 locations, expected damage and required protection from that damage is not the
same in every application. Question - What practical guidelines are available to installers and
enforcement to apply this phrase and associated protection in a uniform manner?
Panel Response: o
Question 3: Statement – New NEC Article 840, Premises-Powered Broadband Communications
Systems states the optical fiber cable to the premises may be nonconductive or conductive. I
thought optic fiber cables were nonconductive. Question – Can someone please explain when a
system would be conductive or nonconductive, the need for each system if there is a specific
need, and if conductive, is there a voltage involved?
Panel Response: o
Question 4: Statement – NEC 702.4(B) (2) requires optional standby sources, utilizing
automatic transfer equipment, to be sized to supply the full load, calculated in accordance with
Article 220, or employ a load management system. Question - Does this require the load
management system to be included with the source (normally a generator), in the transfer
equipment, or as a separate piece of equipment?
Panel Response: o
Question 5: Statement – The 2005 NEC, Section 505.7(A) stated “Classification of areas and
selection of equipment and wiring methods shall be under the supervision of a qualified
Registered Professional Engineer.” For this same section, the 2008 NEC substituted “qualified
persons” for” Registered Professional Engineer.” One of the comments accepted in the NFPA 70
– A98 ROC concerning the need for a Registered Professional Engineer to supervise the
classification, selection of equipment, wiring methods, installation, and inspection for a Zone
type installation stated “This requirement [Registered Professional Engineer] was a major reason
the new Article 505 was accepted. The zone system is new and unique. It is a modified IEC
system; it does nothing to harmonize standards. The term “qualified person” is inappropriate as
defined in Article 100 to determine the qualifications of a designer of Class I hazardous
locations…….” In addition, look at the FPNs and now Informational Notes that have been
added since inception of the Zone hazardous classification method in the NEC. Especially see
2011 NEC, Section 505.4(B) Informational Note that states:
“It is important that the authority having jurisdiction be familiar with recorded industrial
experience as well as with standards of the National Fire Protection Association (NFPA), the
American Petroleum Institute (API), the Instrumentation, Systems, and Automation Society
(ISA), and the International Electrotechnical Commission (IEC) that may be of use in the
classification of various locations, the determination of adequate ventilation, and the protection
against static electricity and lightning hazards.
Question 1 - How many authorities have this knowledge? Question 2 - So, why without any
technical substantiation was Registered Professional Engineer changed to qualified person in the
2008 NEC and especially as we still have very few to almost no Zone installations to draw
experience from since the Zone classification’s inception in the 1996 NEC?
Panel Response: o
Question 6: Statement – Article 220 includes requirements to calculate branch-circuit & feeder
loads. Articles 210 & 215 include requirements for sizing conductors & overcurrent protection
for those loads. Question 1 - If those loads are supplied by a: UPS; generator; transformer; phase
converter; storage batteries; or Solar PV, Fuel Cell, Wind Electric Systems; does the NEC
require that source to be sized for the load calculated in Article 220? Question 2 - If the NEC
includes source sizing, where are those requirements?
Panel Response: o
Question 7: Are there any communication cables designed for use in ducts specifically
fabricated for environmental air as identified in 300.22(B) and would these cable, if any, be
allowed for any wiring application?
Panel Response: o
Question 8: Do the requirements in Chapters 1-4 of the NEC apply to circuits and equipment
supplied from a DC source?
Panel Response: o
Question 9: Statement – 2011 NEC Section 514.13 states “Each dispensing device shall be
provided with a means to remove all external voltage sources, including power, communications,
data, and video circuits and including feedback, during periods of maintenance and service of the
dispensing equipment.” Question 1 - How is this expected to be accomplished without installing
separate dedicated dispensing device panelboards having shunt-trip main capabilities? Question
2 - Also, if a dedicated shunt-trip main panelboard is utilized would the remote shunt-trip control
be classified as a disconnecting means as defined by the NEC in meeting the intent of 514.13?
Panel Response: o
Question 10: Is a circuit extending from an overcurrent device to the primary terminals of a
transformer considered a branch circuit or a feeder?
Panel Response: o
Question 11: Where ceiling lighting over a health care patient care area is more than 7 ½ ft.
above the floor with the switch controlling the lighting being in the room where the patient care
area is located, but being outside the patient care vicinity, is a conduit or sheath qualified
equipment-grounding conductor plus insulated wire equipment-grounding system required to be
installed per 517.13?
Panel Response: o
Question 12: Statement – Where building departments adopt the IBC, Chapter 13 requires the
buildings to comply with the IECC energy provisions. The IECC requires recess lighting that
penetrates the air barrier of the building to be air tight, IC rated, and sealed to drywall. It requires
outlet boxes that penetrate the air barrier to be air sealed-type. Marked “air tight” luminaires and
“air sealed” boxes are available. Question - Does the product certification standards confirm all
the above features?
Panel Response: o
Question 13: Question 1) Is it permissible to use any raceway wiring method in NEC Chapter 3
to install communication wires and cable in any occupancy? Question 2) Are the raceway fill
requirements in NEC Chapters 3 and 9 applicable to such installations? Question 3) Which
cable types may be used in fabricated ducts, in other spaces used for environmental air, in riser
applications, and in buildings in other that air-handling spaces and riser applications?
Panel Response: o
Question 14: Statement – A 75 KVA, 480 to 240/120 volt, 3-phase, dry-type transformer is
installed to supply a panelboard supplying HVAC, utilization equipment, and receptacle loads.
Question - Based on the tap rules in 240.21 (C)(2), the ampacity provisions in 310.15(B), and the
overcurrent protection requirements in 450.3 (B), what size secondary conductors [assume 86°F
and the 3 phase, 4-wire circuit in raceway] and secondary overcurrent device are required?
Panel Response: o
Question 15: Question 1) Are the requirements of 310.10(C) applicable to communication wires
and cables installed both above and below ground? Question 2) Is there required clearances
between a 120/240 volt service drop and a communications service drop at both the pole and at
the attachment at a building?
Panel Response:
Question 16: Reference – “Appliance. Utilization equipment, generally other than industrial,
that is normally built in standardized sizes or types and is installed or connected as a unit to
perform one or more functions such as clothes washing, air conditioning, food mixing, deep
frying, and so forth.” Statement - NEC Article 422 obviously includes the installation
requirements for appliances; however this definition is broad enough to also cover the equipment
included in Articles 424 through 440 and some of the equipment included in Chapters 5-7.
Question 1) - What practical guidelines are available to designers, installers, and AHJ’s to
properly apply installation requirements to utilization equipment. Question 2) If industrial
utilization equipment that is normally built in standardized sizes or types and is installed or
connected as a unit to perform one or more functions is not considered an appliance, what is that
equipment considered and which NEC Article covers its installation?
Panel Response: o
Question 17: Question 1) Is there any special requirements for mounting a receptacle outlet
serving a hydromassage bathtub when the receptacle is accessible through a service access
opening? Question 2) Is there a minimum dimension for a service access opening to the pump
motor and other associated electrical equipment beneath an enclosed hydromassage bathtub?
Panel Response: o
Question 18: Statement – NEC 450.3(B) includes requirements for transformer overcurrent
protection, 600 volts or less. Table 450.3(B) offers two options for protection, primary only or
primary and secondary protection. NEC 240.21(C) requires secondary conductor protection for
all single-phase, 3 wire and multi-phase, 4 wire units. Question - Does that omit the option for
primary only protection for those transformers?
Panel Response: o
Question 19: Statement – A 1½ HP swimming pool pump motor is installed as part of a
swimming pool installation at a residence. The pump is 240-volt, single-phase rated and
protected by a 25 amp rated circuit breaker which calculates to be 250-percent of the motor FLA
which is normal with 430.52(C)(1) and Table 430.52. Question - Does this pool pump require
GFCI protection be installed for personnel protection?
Panel Response: o
Question 20: Reference – “Continuous Load. A load where the maximum current is expected
to continue for 3-hours or more.” Question - What practical guidelines are available to installers
and enforcement to apply this definition?
Panel Response: o
Question 21: Question 1) Is it an NEC violation to install the grounding electrode conductor
from a cable TV service drop or a telephone service drop directly to the grounded bus of a power
service panel or is an intersystem bonding terminal assembly required to be installed? Question
2) Why is an 8 ft. long ground rod required for a power system grounding electrode while only a
6 ft. long ground rod is allowed for communication systems besides the fact the
telecommunications industry member of CMP-16 continues to sell other CMP-16 members on
the fact that the 6 ft. rod is adequate.
Panel Response: o
Question 22: Are Class 3 control circuits allowed in the same raceway with power conductors
from a generator that serves a dc drive motor on a kid’s ride at a state fairgrounds?
Panel Response:
Question 23: Question 1) For health care facilities what are the requirements for ground-fault
protection where ground-fault protection is provided at the service disconnecting means or feeder
disconnecting means? Question 2) Where ground-fault protection is used at the service
disconnecting means or feeder disconnecting means, is the ground-fault protection compatible
where selective coordination may also be required? Question 3) Who should performance test
the ground-fault protection installation to see if it is properly operating; the inspector, the
contractor, the manufacturer, or a third party testing agency?
Panel Response: o
Question 24: Statement - NEC 450.3(B) includes requirements for transformer overcurrent
protection, 600 volts or less. Where primary and secondary protection is provided, Table
450.3(B) indicates the primary protection can be sized at 250% of the transformer rated current.
Question - Are primary conductors required to be sized to match the rating of the primary
overcurrent protective device, the primary current rating of the transformer, or for some other
value?
Panel Response: o
Question 25: Question 1) Where optical fiber cables are utilized as critical circuits for use in
systems required to have survivable characteristics for a specific time period during fire
conditions, is there any special listing conditions for such cables? Question 2) If question one is
yes, does the NEC set a minimum time that the cable must survive during a fire such where the
cable serves communication circuits to and from an emergency command building?
Panel Response: o
Question 26: Statement - Consider Location, Dry, Location, Damp, and Location, Wet. Some
locations are clearly dry or wet and generally easy to distinguish. Other areas are damp, but may
be classed dry or damp. Question 1) What practical guidelines are available to installers and
enforcement to apply the preceding definitions? Question 2) Would those guidelines use the
amount of moisture, how frequently the installation is exposed to moisture or liquid, or a
combination of those and other factors. Classify the following installations:
Panel Response: o
Question 27: Statement - NEC Section 547.9 addresses service disconnecting means and
overcurrent protection at multiple distribution points serving agricultural buildings. This section
states “Where a site is supplied by more than one service with any two services located a
distance of 150 m (500 ft) or less apart, as measured in a straight line, a permanent plaque or
directory shall be installed at each of these distribution points denoting the location of each of the
other distribution points and the buildings or structures served by each.” Question 1) Why are
branch circuits run from the distribution points not also identified at each building as to which
distribution point the branch circuit originates from? Question 2) Also, why was the 500 ft. or
less distance chosen as the maximum distance for requiring such identification, as 500 ft. is not
too far when considering the size of most farms and ranches?
Panel Response: o
Question 28: Statement - An individual circuit is installed from an overcurrent device to the
primary terminals of a 300 KVA, 480 to 208Y/120 volt, 3-phase, dry type transformer. Question
1) What size primary overcurrent devices are required and/or permitted by Table 450.3(B)?
Question 2) Based on one set of copper conductors, installed in an 86°F ambient, with no
additional conductors in the raceway, what size conductors are required for each of the
overcurrent devices permitted in Table 450.3(B)?
Panel Response: o
Question 29: Statement - The NEC states that non-power limited fire alarm cables and power
limited fire alarm cables for use in plenums and ducts shall be listed as having adequate fireresistant and low smoke-producing characteristics. Question 1) What is “adequate” as the 2011
informational note on this subject merely provides a way of defining a cable that is low smokeproducing and fire resistant? Question 2) Are the 0.5 or less optical density and the maximum
flame spread rating of 5 ft. considered adequate? Question 3) What does 0.5 optical density
mean? Question 4) What does a flame spread of 5 ft. mean?
Panel Response: o
Question 30: Reference - Overcurrent. Any current in excess of the rated current of equipment
or the ampacity of a conductor. It may result from overload, short circuit, or ground fault.
Question - Based on this NEC definition, are high impedance faults considered overcurrent?
Panel Response: o
Question 31: When a minimum 8 AWG copper bonding conductor is utilized to bond the hot
and cold copper water piping rising from the ground to serve a hydromassage bathtub plus other
metal bracing installed under the hydromassage bathtub why is it required to run the bonding
conductor to the location of a double insulated circulating pump motor when the bond wire is not
required to be connected to anything?
Panel Response: o
Question 32: Statement - An individual circuit is installed from an overcurrent device to the
primary terminals of a 75 KVA, 480 to 240/120 volt, 3-phase, dry-type transformer. Question 1)
What maximum size primary overcurrent devices are required and/or permitted by Table
450.3(B)? Question 2) Based on one set of copper conductors, installed in an 86°F ambient, with
no additional conductors in the raceway, what minimum size conductors and minimum size
electrical metallic tubing are required?
Panel Response: o
Question 33: As there has been a lot of documentation concerning incidents in which people
have been killed or injured due to leakage currents on or around marinas and other structures
such as floating building, has there been any thought to requiring GFCI protection for all such
feeder and branch circuits, especially shore power receptacles and associated plug-and-cord
connections installed at marinas and similar installations?
Panel Response: o
Question 34: Reference - Overcurrent Protective Device, Branch-Circuit. A device capable
of providing protection for service, feeder, and branch-circuits and equipment over the full range
of overcurrents between its rated current and its interrupting rating. Question Why are these
devices titled “Branch Circuit” when the definition obviously includes service and feeder
protective devices?
Panel Response: o
Question 35: Statement – A 32 building apartment complex has a house panelboard for other
than dwelling electrical loads for every 4 buildings. A fire alarm circuit feeding fire alarm
equipment extends from each outdoor house panelboard to the building it is on and 3 other
buildings. Question - Are there any NEC requirements that would require identification of the
location of the fire alarm circuit branch circuit overcurrent protective device at the other
buildings, at the fire alarm equipment at each building, or at the origination point of the fire
alarm circuit?
Panel Response: o
Question 36: Statement - The NEC and product standards allow generators to be installed as
separately derived systems or as non-separately derived systems. Selection of the system type
and associated installation requirements is based on the transfer equipment. Neither the NEC nor
product standards (UL2200 or 2201) require or prohibit generator manufacturers from providing
and/or installing a main bonding jumper with the generator. Neither the NEC nor product
standards (UL2200 or 2201) require generator manufacturers to provide marking to indicate a
main bonding jumper is provided and/or installed by the generator manufacturer. Question How
are designers, installers, and AHJ’s to determine if a bonding jumper is provided and ensure the
installation, the transfer equipment, and the generator are coordinated?
Panel Response: o
Question 37: Are receptacles installed in wet locations at construction sites for temporary power
supply required to be listed weather-resistant type and are such receptacle outlets required to be
equipped with a weatherproof cover that is weatherproof whether or not an attachment plug cap
is inserted?
Panel Response: o
Question 38: Statement - A supplementary overcurrent protective device is defined in Article
100 as: a device intended to provide limited overcurrent protection for specific applications and
equipment. The limited protection is in addition to the branch circuit protection. Question 1) - Is
it possible that an overcurrent protective device, branch-circuit could be utilized as a
supplementary overcurrent device? Question 2) - If so, how will designers, installers, and AHJ’s
know which set of requirements apply to the device?
Question 3) Are branch-circuit
overcurrent devices and supplementary devices individually marked to help alleviate any
confusion or are they simply recognizable without special marking?
Panel Response: o
Question 39: Statement 1) - NEC 600.4 (A) requires signs to be marked with the manufacturer’s
name, trademark, or other means of identification; and input voltage and current rating.
Question 1) - Are these markings required to be on the exterior surface of the sign so that an
inspector can readily access this information? Statement 2) - NEC Section 600.5(A) requires’
each commercial occupancy accessible to pedestrians to be provided with at least one 20-ampere
outlet in an accessible location at each entrance for a sign or outline lighting. Question 2) Are
such 20-ampere branch circuits considered to be a continuous load?
Panel Response: o
Question 40: Statement - Tap conductors are installed from the secondary terminals of a 150
KVA, 480 to 208Y/120 volt, 3-phase, dry type transformer. Question - Based on a 10-foot tap
and one set of copper conductors, installed in an 86°F ambient, with no additional conductors in
the raceway, what size conductors are required if the tap terminates into a 400 ampere main
circuit breaker panelboard?
Panel Response: o
Question 41: Statement - According to 2011 NEC Section 590.6(A)(3) all 125-volt and 125/250
volt, single-phase 15-, 20-, and 30-ampere receptacles outlets that are part of a 15-kW or smaller
portable generator shall have listed GFCI protection for personnel. It was my understanding that
most of the commercially available small inverter generators feature a floating neutral and that
adding GFCI protection to the receptacles will serve no purpose, as it will be completely
ineffective on a floating neutral generator because the ground and neutral are not tied together.
Question - Can you please explain the basis by which this requirement was accepted into the
Article 590?
Panel Response: o
Question 42: Statement - A 50 KVA, 480 to 240/120 volt, 1 phase, dry-type transformer is
installed to supply a single-phase panel supplying HVAC, utilization equipment, and receptacle
loads. Question - Based on the tap rules in 240.21(C)(2), the ampacity provisions in 310.15(B),
and the overcurrent protection requirements in 450.3 (B), what size secondary conductors
[assume 86°F & not more than 3 conductors in raceway] and secondary overcurrent device are
required?
Panel Response: o
Question 43: Question 1) Where Class 2 and 3 remote control circuits installed in raceways in
high rise buildings are run vertically from the basement to all floors of the building, is there any
vertical support required? Question 2) Where Class 2 and 3 power limited circuits are partially
protected by raceway for physical damage issues, is a bushing required where the circuits emerge
from the raceway?
Panel Response: o
Question 44: Based on NEC definitions of overcurrent and overcurrent protective device,
branch-circuit; is it safe to assume that high impedance faults and/or faults in high impedance
portions of circuits could possibly go undetected by standard overcurrent protective devices?
Panel Response: o
Question 45: Statement - In some applications, receptacles are identified by a distinctive
marking such as hospital grade receptacles that have a green dot, isolated grounding type
receptacles that have an orange triangle, etc. Question - Is there a required marking for
receptacles connected to a critical operations power system so that they may be readily identified
for use during power outages to the normal power system?
Panel Response: o
Question 46: Statement - NEC 445.13 includes conductor sizing (ampacity) requirements from
generator terminals to the first distribution device(s). Question 1) Is it possible for those
conductors to be part of the generator assembly and also possible for the conductors to be field
installed? Question 2 Is it possible that larger branch-circuit or feeder conductors would be
required from the first distribution device(s) from a generator to the load or next distribution
device, than the conductors addressed in 445.13? Question 3 Would the sizing of those
conductors from the first distribution device(s) from a generator to the load or next distribution
device be based on 445.13 or the requirements in 210.19 or 215.2?
Panel Response: o
Question 47: Question 1) - Are there any requirements for installing conductors and equipment
on the supply side of a Class 2 power source used in a sign or outline lighting installation?
Question 2) - What are the requirements for installing secondary wiring from a Class 2 power
source used in a sign or outline lighting installation?
Panel Response: o
Question 48: Statement - NEC 430.7(A)(15) includes nameplate marking requirements for
condensation prevention heaters installed in motors. Question - Where does the NEC include
requirements for sizing supply circuits and overcurrent protection for those heaters?
Panel Response: o
Question 49: Statement - A contractor has run ¾ in. PVC conduit under a deck around a pool to
serve a wet-niche luminaire, with the pool decking consisting of 4 in. thick concrete with a
“cool-deck” coating. He said he referenced 300.5 which states the PVC may be installed directly
under 4 in. thick concrete. The inspector referenced 680-10 that states “Underground wiring
shall not be permitted under the pool or within the area extending 1.5 m (5 ft) horizontally from
the inside wall of the pool unless this wiring is necessary to supply pool equipment permitted by
this article” and that there are no spacing limitations concerning this installation. Question What is your opinion?
Panel Response: o
Question 50: Statement - NEC Article 100 now includes a definition for an “uninterruptible
power supply”. The term is only used in Chapters 6 and 7 of the NEC. General installation
requirements for circuits and protection are located in Chapter 4 for other equipment types, e.g.,
appliances, motors, heating equipment, generators, etc., but Chapter 4 does not include an Article
for “UPS” equipment. Question 1) Are designers, installers, and AHJ’s required to size the UPS
based on the load (calculated by the requirements in Article 220) that is connected to the output
circuit or can this equipment be sized based on expected diversity of those loads? Question 2)
Since NEC 110.21 only requires voltage, current, wattage or other ratings as specified elsewhere
in the Code, what type markings should installers and AHJ’s expect to find on UPS equipment?
Question 3 Should designers, installers, and AHJ’s consider the UPS a continuous load while
sizing the supply circuit and overcurrent device for the UPS? Question 4) Should designers,
installers, and AHJ’s consider the UPS a separately derived system? Question 5) If the UPS
equipment can be supplied by the manufacturer as separately derived system or not, will the
equipment be marked to inform the installer and AHJ? Question 6) Is a disconnecting means
required for UPS equipment? Question 7) If so, is it required to be provided within sight of the
equipment?
Panel Response: o
Question 51: Where a 277/480 volt, 3-phase, solidly grounded wye voltage system serves a
legally required standby system utilizing 1000 ampere or more circuit protective devices, is there
any special requirements for installing ground fault protection?
Panel Response: o
Question 52: Statement - Household Electric Storage Tank Water Heaters (KSDT) are required
to be equipped with temperature regulating devices and temperature-limit controls to restrict
water temperature. That device would likely limit the load to a time of less than 3-hours.
Question - What substantiation was submitted that justifies the requirement in 422.13 for
storage-type water heaters to be considered a continuous load?
Panel Response: o
Question 53: Statement - 2008 NEC Section 702.8(B) states that where the grounded circuit
conductor connected to an optional standby power source is connected to a grounding electrode
conductor at a location remote from the optional standby power source, there shall be a sign at
the grounding location that identifies all optional standby power and normal sources connected at
that location. Question - What should be the wording on such signs?
Panel Response: o
Question 54: Statement - An individual circuit is installed from an overcurrent device to the
primary terminals of a 50 KVA, 480 to 240/120 volt, 1 phase, dry-type transformer. Question 1)
– What maximum size primary and secondary overcurrent devices are required and/or permitted
by Table 450.3(B)? Question 2) - Based on one set of copper conductors, installed in an 86°F
ambient, with no additional conductors in the raceway, what minimum size conductors are
required based on each of the primary and secondary overcurrent devices permitted in Table
450.3(B)?
Panel Response: o
Question 55: Statement - A manufacturer of stand-alone load control relays, UL 924 devices,
states his product is a “transfer device” that can be used to switch loads such as emergency
lighting from a normal supply to an alternate emergency power supply. It is my understanding
that transfer equipment for emergency loads rated 600 volts and less shall be listed for
emergency system use such as a device listed to UL 1008. Question - Could you please explain?
Panel Response: o
Question 56: Statement - NEC 110.11 requires conductors and equipment installed in wet or
damp locations or exposed to agents with a deteriorating effect to be identified for that operating
environment. Question 1) What type connectors and terminals have been evaluated for use in the
wet and damp, chlorine environments associated with equipment included in Article 680?
Question 2) What type connectors and terminals have been evaluated for use in other corrosive
environments?
Panel Response: o
Question 57: Statement – For other than industrial establishments, solid dielectric insulated
conductors operated above 2000 volts in permanent installations shall have ozone-resistant
insulation and shall be shielded. Question – Under what conditions and for what type systems
can a metallic insulation shield encircling over 1 kV current carrying conductors be permitted to
be used as an equipment-grounding conductor?
Panel Response: o
Question 58: Statement - NEC 110.14 requires connectors and terminals for conductors more
finely stranded than Class B and Class C stranding to be identified for the specific class or
classes. Question 1) Is such identification uniform among all manufacturers? Question 2) Can
you provide examples of the identification.
Panel Response: o
Question 59: Statement - 2011 NEC 695.4(B)(2)(b) states “Overcurrent protective devices
between an on-site standby generator and a fire pump controller shall be selected and sized to
allow for instantaneous pickup of the full pump room load, but shall not be larger than the value
selected to comply with 430.62 to provide short-circuit protection only.” In addition, see 2011
NEC 695.6(C) that states “Power circuits shall not have automatic protection against overloads.
Except for protection of transformer primaries provided in 695.5(C)(2), branch-circuit and feeder
conductors shall be protected against short circuit only.” Question - Therefore, would the
overcurrent protective device in question in 695.4(B)(2)(b) between the generator and fire pump
controller be required to be an instantaneous circuit breaker (no overload protection) and also not
have to follow the requirements of 430.51(C)(3)?
Panel Response: o
Question 60: Statement - NEC 406.14 now requires tamper-resistant receptacles in child care
facilities. Question 1) How will designers, installers, and AHJ’s determine which facilities
qualify as “child care”. Question 2) How does the intent of the 2011 NEC in identifying child
care facilities differ from the International Building Code or Governmental Administration
Services identification?
Panel Response: o
Question 61: Is it permissible to utilize festoon type wiring as a wiring method for supplying a
hoist motor where flexibility is required, and can this type of wiring method be utilized with
bridle rings to control the movement of the cable when the motor moves horizontally?
Panel Response: o
Question 62: Statement - The AFCI requirements in NEC 210.12 are limited to dwelling units.
Question 1) Do arcing faults occur in non-dwelling occupancies with no need for AFCI in such
installations? Question 2) If so, do the thermal magnetic overcurrent devices provide protection
from those faults in non-dwelling occupancies? Question 3) In addition, what do you think will
happen with the 2014 NEC – will we have more ways added to use outlet branch-circuit type
AFCI devices and more requirements for AFCI as a required safety device for existing
installations with no outlet branch-circuit type devices available once again?
Panel Response: o
Question 63: Why is there a specific Article definition in Article 701 for a legally required
standby system and a specific Article definition in 702 for an optional standby system but no
specific definition for an emergency system in Article 700?
Panel Response: o
Question 64: Statement - Some wet and damp location outlet box hoods for receptacle outlet
installations are required to be identified as “extra-duty”. Question 1) What is the significance of
the seeming exemption from listing for one- or two-family dwellings concerning box hoods?
Question 2) Also, please explain “on an enclosure supported from grade” as applied to the
requirement for an “extra duty” box hood? Would this mean that a 20-ampere, 120-volt
receptacle outlet installed in a wet location on a floating building or floating marina dock would
not require such a box hood?
Panel Response: o
Question 65: Question 1) Are there any special conditions required for supplementary grounding
electrodes used to limit voltages imposed by lightning on a wind generator? Question 2) Is it
permissible to utilize the guy wires used to steady a wind turbine tower as part of a lightning
protection system, and if yes, are there any special requirements for using the guy wires and their
support footings?
Panel Response: o
Question 66: Where multiple motors are used to drive a bridge crane as a unit and are protected
by a single set of overload devices with a rating equal to the full load current of the all the
motors, how is an over-temperature condition handled that may happen in any of the individual
drive motors?
Panel Response: o
Question 67: Statement - The minimum ampacity and conductor size for branch circuits is
covered in NEC 210.19 and generally requires an ampacity rated for the non-continuous load
plus 125 percent of the continuous load. Question 1) Do the ampere ratings on equipment
typically reflect that value or do those nameplate ampere ratings reflect the full load amperes
without consideration of continuous and non-continuous use? Question 2) Is the same process
used to determine the nameplate ampere ratings for all equipment?
Panel Response: o
Question 68: Question 1) Does the NEC now prohibit the use of 12/2 W/G cable assemblies at
single pole switch locations? Question 2) Does it prohibit the use of 12/3 W/G cable assemblies
at three way switch locations?
Panel Response: o
Question 69: Statement - 2011 NEC 695.4(B)(3)(b) references 700.10(B)(5) regarding an onsite standby generator disconnecting means where the generator is use as an alternate power
source for a fire pump installation. 700.10(B)((5) does not address fire pumps directly, but rather
addresses combinations of emergency, legally required, and optional standby loads served by an
emergency power source. It should be noted that 2008 NEC 695.4(A) required a fire pump
disconnecting means to be located in a separate enclosure from the other generator disconnecting
means and while no such wording appears in the 2011 NEC, no technical substantiation has been
found to justify a change to this 2008 NEC requirement. Question 1) Is it permissible for a
disconnecting means serving a fire pump to be contained in a one section of a four section
vertical switchboard with the other three sections serving emergency, legally required, and
optional standby loads where the switchboard is served by either a common bus or by individual
feeder conductors to each section of the switchboard Question 2) The NEC does not specifically
set a pecking order between a fire pump and an emergency system in sizing a generator serving
both types of loads. In sizing a generator that serves a fire pump, emergency loads, legally
required standby loads, and optional standby loads, what would be the pecking order for load
shedding where the generator is not sized at 100% or more of the connected loads?
Panel Response: o
Question 70: Questions 1) Are all ENT fittings suitable for use in poured concrete and for wet
locations? Question 2) What characteristics of ENT make it suitable for use in poured concrete,
but prohibit direct burial installations. Question 3) Has UL reversed itself on concrete
encased/direct burial listed fittings, as at past code workshops UL has stated that if a listed item
is listed for concrete encasement it is listed for direct burial such as rebar grounding clamps?
Panel Response: o
Question 71: Statement - The minimum rating of the overcurrent device for branch circuits is
covered in NEC 210.20 and generally requires a rating not less than the non-continuous load plus
125 percent of the continuous load. The (B) part of 210.20 indicates conductors must be
protected according to 240.4 and cords and fixture wires according to 240.5. Part (C) of 210.20
indicates the rating shall not exceed the value specified in Table 240.3 for the equipment.
Question 1) When the maximum value of the overcurrent device is determined by the
requirements included in Table 240.3, does that overcurrent protective device protect all internal
wiring and components within the utilization equipment that is connected to the branch-circuit?
Question 2) How is the maximum value of the overcurrent device determined if the equipment is
not included in Table 240.3? Question 3) What is the maximum value permitted for the
overcurrent device protecting the following pieces of equipment?
Panel Response: o
Question 72: Statement - A new requirement was added as 692.4(C), Fuel Cell Systems, in the
2011 NEC that requires “Fuel cell systems including all associated wiring and interconnections
shall be installed by only qualified persons.” This overused reference to “qualified persons” is
being added more and more in too many NEC Articles. In addition, 90.4 states “This Code is
intended to be suitable for mandatory application by governmental bodies that exercise legal
jurisdiction over electrical installations, …” Most jurisdictions require licensed electricians to
install or at least supervise electrical installations in their jurisdictions, and with such licensing
the issuing jurisdiction allows the holder to make any electrical installation covered by their class
of license. Question 1) How is the now general requirement referencing “qualified persons”, as
defined in Article 100 to be enforced, and especially as it has been pointed out in CMP-1
discussions that jurisdictions have no desire to keep track of specific installations that each such
licensed electrician is qualified to install. Qualified 2) In essence, which electrical installations
covered by the NEC should not require qualified persons as a general rule?
Panel Response: o
Question 73: Statement - 2011 NEC 310.10(H)(3) states in part “Where run in separate cables or
raceways, the cables or raceways with conductors shall have the same number of conductors and
shall have the same electrical characteristics.” A parallel conductor branch circuit is run from a
switchboard to a 3-phase rooftop air-conditioning unit using two 2½ in. conduits with four 4/0
AWG copper conductors (3-phase, 1 grounding) in each conduit, plus six 10 AWG Class 1, 120volt control conductors are run in one of the 2½ in. conduits. Question - Would the addition of
the control conductors in one conduit of this power circuit run in parallel be a violation of having
the same number of conductors and the same electrical characteristics in each conduit?
Panel Response: o
Question 74: Statement - NEC 225.2 includes the following definition for substation. “An
enclosed assemblage of equipment (e.g., switches, circuit breakers, buses, and transformers)
under the control of qualified persons, through which electric energy is passed for the purpose of
switching or modifying its characteristics.” Question 1) Based on that definition, could
industrial control panels, motor control centers, or process/utilization equipment now be
considered a substation? Question 2) Based on that definition are the requirements in 225.70
applicable to unit substations and metal-clad switchgear?
Panel Response: o
Question 75: Statement - It is required that elevators have a single means for disconnecting all
ungrounded car light, receptacle(s), and ventilation power-supply conductors for that elevator
car. The disconnecting means is required to be an enclosed externally operable fused motor
circuit switch or circuit breaker capable of being locked in the open position. Question - Could a
general-use snap switch suitable only for use on ac be utilized per 430.109(C) if it can be
installed where it can be locked in the open position?
Panel Response: o
Question 76: Question 1) Can the revisions in 338.10(B)(4) result in different SE cable sizes to
identical loads on the same project, based on cable routing? Question 2) Why do the
requirements in 338.4(B)(4)(a) only deal with “installed in thermal insulation” and fail to
specifically address the extreme heat that raises the ambient temperature to at least over 125degrees in attics during the summertime nearly everywhere in the US? Question 3) Are the 3wire and 4-wire aluminum and copper conductors utilized in SE cables installed in dwelling
construction rated at 75-degree C or at 90-degree C and which column in 310.15(B)(16) does one
start a deration calculation from (please give an example)?
Panel Response: o
Question 77: Question 1) Is it required to run a bond wire from a photovoltaic inverter
grounding electrode system to the intersystem bonding terminal at the normal service disconnect
means served by the utility? Question 2) If the answer to question one is yes, what is the
minimum size for such bonding conductor? Question 3) Where a photovoltaic system serves
both dc and ac circuits with no direct connection between the dc grounded conductor and the ac
grounded conductor, would each system be required to have separate grounding electrode
systems and to what all would be these systems be required to be bonded?
Panel Response: o
Question 78: Statement 1) - Where an outside branch circuit or feeder enters a building or
structure from an underground distribution system, the raceway is required to be sealed in
accordance with 300.5(G). Question 1 - What is an underground distribution system? Question
2) If a branch circuit or feeder is installed underground from one building or structure to another,
is that an underground distribution system? Statement 2) - The IAEI Analysis assessment of the
new requirement in 225.27 and existing requirement in 230.8 seems to indicated that a short
sleeve that extends underground from a meter base to a pad mounted transformer is required to
be sealed. Question 3) Doesn’t both 230.8 and 225.27 speak to raceways and not to sleeves
simply used for physical protection and mostly above grade? Question 4) As both 225.27 and
230.8 refer to 300.5(G), 300.5(G) appears to be a conditional requirement that is only required
when “moisture may contact live parts” – is that true? Question 5) If true, what is the criteria for
making that judgment, as live parts are not normally right above a conduit coming up from the
ground such as a meter enclosure or panelboard?
Panel Response:
Question 79: Question 1) Is each 120-volt receptacle required for an electrified truck parking
space required to be served by an individual 120-volt branch circuit? Question 2) Is there a
minimum number of 120-volt receptacles required for each electrified truck parking space?
Panel Response: o
Question 80: Statement - Occasionally, circular raceways are damaged after installation. In
some cases the raceway prevents damage to the enclosed conductors. Question 1) Are two piece
repair kits permitted, available, and listed to repair raceway wiring methods without having to
remove and re-install conductors? Question 2) if available, are any of these kits listed or listed
for the purpose?
Panel Response: o
Question 81: Question 1) Where conductors from both dc and ac photovoltaic systems utilize a
common j-box or other enclosure with an access cover, is any special identification required as to
which photovoltaic system each conductor belongs? Question 2) Where photovoltaic circuits are
run inside a building, whether in conduit or not, can these circuits be run embedded within
insulation and if so, is there any derating of such conductors required?
Panel Response: o
Question 82: Statement 1) NEC 250.104(C) requires exposed structural metal that is
interconnected to form a metal building frame and is not intentionally grounded or bonded and is
likely to become energized to be bonded similar to a grounding electrode. Question 1) What
purpose does the words “and is not intentionally grounded or bonded” serve in that requirement,
since the rest of the sentence requires that metal structure to be intentionally bonded? Statement
2) NEC 250.104(C) requires exposed structural metal that is interconnected to form a metal
building frame …….. to be bonded….. Question 2) How does an installer and AHJ determine
how much structural metal constitutes an interconnected metal building frame? Statement3)
NEC 250.104(B) states in part “….a metal piping system(s), including gas piping, that is likely
to become energized shall be bonded...” Question 3) Does this requirement include CSST gas
piping that states it does not require bonding such as “Flash Shield?”
Panel Response: o
Question 83: Statement - 2011 NEC 630.13 added the word “identified” as a descriptive word
for disconnecting means. Question 1) Is the word “identified” being used in the sense of the
definition of “identified” in Article 100 or in the sense of 110.22, Identification of Disconnecting
Means, to indicate its purpose?
Panel Response: o
Question 84: Question 1) Do conductors of AC and MC cable perform differently when
installed in thermal insulation as the NEC requirements seem to indicate they do? Question 2)
Has that performance been determined through fact finding studies?
Panel Response: o
Question 85: What is the maximum voltage that a photovoltaic system may operate at that has
both dc source circuits and ac output circuits where the circuits are run on a building before the
photovoltaic system is required to be protected by a listed (dc) arc-fault circuit interrupter, or
other protective system listed to provide equivalent protection?
Panel Response: o
Question 86: Statement - 2008 NEC Article 280 was completely re-written through proposal 5340 with an added new requirement that surge arresters, over 1 KV to be listed. This proposal
was introduced by UL in advance of a new UL1449 publication. That requirement was removed
due to a 2011 NEC revision of Article 280. However, NEC 110.2 continues to require approval
of that equipment. Question) Why was the listing requirement removed from the 2011 NEC and
what should AHJ’s now use as a basis of approval for such equipment?
Panel Response: o
Question 87: Statement - NEC 314.27(A)(2) seems to require all ceiling boxes used to support
luminaires be able to support a minimum of 50 pounds. Question 1) - Are all round and octagon
outlet boxes, including ½-inch pancake boxes, evaluated to support 50 pounds? Question 2) Are
all metallic outlet boxes for luminaire support identified for that purpose? Question 3) Are there
any round or device type nonmetallic boxes listed for supporting a 50 pound luminaire, and if
not, are they marked with a maximum support weight? Question 4) Are nonmetallic device
boxes listed, identified or marked in any way to meet 314.27(A)(1), Exception?
Panel Response: o
Question 88: Question 1) Is information technology equipment allowed to be plug- and cordconnected if the cord is either hard usage type or portable power cable type, and is such
equipment required to be marked as being suitable for cord- and plug-connection before a cordand plug-connection can be utilized? Question 2) Is there a maximum length for power-supply
cords used to connect informational technology equipment as well as for cables that
interconnects separate information technology equipment? Question 3) 645.10 requires an
approved means to disconnect power to all electronic equipment and HVAC equipment serving
an information technology equipment room. or in designated zones within the room. This section
also requires the control for these disconnecting means to be grouped and identified and readily
accessible at the principal exit doors. Are principal exit doors the same as the fire exit egress
doors?
Panel Response: o
Question 89: For plug- and cord-connected floating equipment at a lake, is the removal of the
cord cap from the receptacle suitable as a disconnecting means for the equipment?
Panel Response: o
Question 90: Statement - NEC 300.22(C)(3) permits electrical equipment with a nonmetallic
enclosure to be installed in other spaces used for environmental air (plenums) where the
equipment is listed for that purpose and having fire-resistant and low-smoke-producing
characteristics. Question 1) Do any such non-metallic enclosures exist? Question 2) How will
designers, installers and AHJ’s be able to identify these products in the field?
Panel Response: o
Question 91: Statement - 680.51(A) requires that luminaires, submersible pumps, and other
submersible equipment installed in a fountain, unless listed for operation at 15 volts or less and
supplied by a transformer that complies with 680.23(A)(2), shall be protected by a ground-fault
circuit interrupter. Such transformers are required to be an isolated winding type with an
ungrounded secondary that has a grounded metal barrier between the primary and secondary
windings. Question - Is this type of transformer and maximum15-volt protection the only way to
install a low voltage lighting system in a fountain?
Panel Response: o
Question 92: Question 1) If a spare ungrounded conductor is installed from switch locations in
dwelling units to ceiling mounted outlet boxes, but not connected to a switch, would the ceiling
mounted outlet box be required to be suitable for fan support? Question 2) Are paddle fan
support rated boxes only required for dwelling occupancies or would a commercial occupancy
that hangs such a fan be subject to the same box requirements as a dwelling unit?
Panel Response: o
Question 93: Is there a minimum size for a neutral conductor used solely for instrumentation,
voltage detection, or phase detection and connected to a single-phase or 3-phase utilityinteractive inverter involving interconnected electric power production sources?
Panel Response: o
Question 94: Statement - NEC 310.10(G) requires conductors installed in corrosive conditions
to have insulation suitable for the application. Question - What type conditions would cause
deleterious effects on conductors or insulation and what type insulation would be suitable for
those applications? Please give an example such as a chlorine manufacturing plant or in a
platting plant with highly corrosive open chemical dipping vats.
Panel Response: o
Question 95: Is any special type of shock protection required in health care facilities for wet
procedure location patient care areas where plug-and-cord-connected, listed, fixed diagnostic
equipment is installed?
Panel Response: o
Question 96: Statement - Some listed manufactured wiring systems contain unlisted flexible
metal conduit of non-circular design with fittings where both seem to be smaller than nominal ⅜
in. diameter. NEC Section 604.6(A)(2), manufactured wiring systems, states “Conduit shall be
listed flexible metal conduit or listed liquidtight flexible conduit containing nominal 600-volt, 8
to 12 AWG insulated copper conductors with a bare or insulated copper equipment grounding
conductor equivalent in size to the ungrounded conductor.” The exceptions to this section seem
to only address specific installations and do not address an exception for general wiring
applications in which a manufactured wiring system may be used. Question - Thus, how can
such manufactured wiring with undersized conduit and fittings be part of a listed manufactured
wiring system?
Panel Response: o
Question 97: Question 1) Can a terminal bar generally used in a panelboard for equipment
grounding conductors be utilized as a terminal bar installed under an outdoor service switch or
panelboard for use as an intersystem bonding termination. Question 2) Could such a terminal bar
be utilized for connecting both intersystem bonding conductors and multiple grounding electrode
conductors from a grounding electrode system as long as all the requirements of 250.94 are met
and the terminal bar has terminals suitable for the largest required grounding electrode
conductor?
Panel Response: o
Question 98: Statement 1) 110.14(B) in Part 1, General, states “Wire connectors or splicing
means installed on conductors for direct burial shall be listed for such use.” Question 1) Does
this requirement apply to splices made underground for over 600-volt conductors? Statement 2)
In addition, new 300.50(B) only states it considers an enclosure installed underground to be in a
wet location but does not require the enclosure to be a wet location listed or identified enclosure
as only the conductors are required to be listed for use in wet locations. Question 2) Why then
does 350.50(B) only require any connections or splices in an underground installation to be
“approved” for wet locations?
Panel Response: o