MECKLENBURG COUNTY
Land Use and Environmental Service Agency
Code Enforcement
Electrical Consistency Meeting November 4TH, 2009
Code Consistency Questions
1. (Q)Does the requirement for AFCI protected receptacles being
those listed in 210.52 mean that extra receptacles would not be
required to be AFCI protected?
(A)The code addresses all receptacles in those areas and they are to be AFCI
protected.
NEC 210.12 (B) Dwelling Units. All 120-volt, single phase, 15- and 20ampere branch circuits supplying outlets installed in dwelling unit family
rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms,
sunrooms, recreation rooms, closets, hallways, or similar rooms or areas shall
be protected by a listed arc-fault circuit interrupter, combination-type,
installed to provide protection of the branch circuit.
2. (Q)We were turned down on a job for installing a track light
installation because it was not listed. The main track was clearly
listed but some pieces were not labeled. What was the reason
for this?
(A)Per the UL White Book page 149, certain manufactured pieces “are not
acceptable for use with a listed track lighting system: 1) receptacle adaptors
that when inserted into a track section will accommodate attachment plugconnected products and 2) power supply cord connectors that when inserted
into the end of a track section enables the track system to serve as a power
supply cord connected to its source of power”
3. (Q)We had a problem with a cover for a porch receptacle cover.
Some are requiring the bubble covers and some are not. How
can we get together on this issue?
(A)Generally bubble covers are needed when the receptacle is in a wet
location and where not protected from weather.
NEC 406.8 Receptacles in Damp or Wet Locations.
(A) Damp Locations. A receptacle installed outdoors in a location protected from
the weather or in other damp locations shall have an enclosure for the receptacle
that is weatherproof when the receptacle is covered (attachment plug cap not
inserted and receptacle covers closed).
An installation suitable for wet locations shall also be considered suitable for
damp locations.
A receptacle shall be considered to be in a location protected from the
w eather w here located under roofed open porches, canopies,
m arquees, and the like, and w ill not be subjected to a beating rain or
w ater runoff. All 15- and 20-ampere, 125- and 250-volt nonlocking receptacles
shall be a listed weather-resistant type.
FPN: The types of receptacles covered by this requirement are identified as 5-15,
5-20, 6-15, and 6-20 in ANSI/NEMA WD 6-2002, National Electrical
Manufacturers Association Standard for Dimensions of Attachment Plugs and
Receptacles.
(B) Wet Locations.
(1) 15- and 20-Ampere Receptacles in a Wet Location. 15- and 20-ampere, 125and 250-volt receptacles installed in a w et location shall have an enclosure
that is w eatherproof w hether or not the attachm ent plug cap is
inserted. All 15- and 20-ampere, 125- and 250-volt nonlocking receptacles shall
be listed weather-resistant type.
FPN: The types of receptacles covered by this requirement are identified as 5-15,
5-20, 6-15, and 6-20 in ANSI/NEMA WD 6-2002, National Electrical
Manufacturers Association Standard for Dimensions of Attachment Plugs and
Receptacles.]
Exception: 15- and 20-ampere, 125- through 250-volt receptacles installed in a
wet location and subject to routine high-pressure spray washing shall be
permitted to have an enclosure that is weatherproof when the attachment plug is
removed.
(2) Other Receptacles. All other receptacles installed in a wet location shall
comply with (B)(2)(a) or (B)(2)(b).
(a)
A receptacle installed in a w et location, w here the product
intended to be plugged into it is not attended w hile in use, shall have
an enclosure that is w eatherproof w ith the attachm ent plug cap
inserted or rem oved.
(b)
A receptacle installed in a wet location where the product intended to be
plugged into it will be attended while in use (e.g., portable tools) shall have an
enclosure that is weatherproof when the attachment plug is removed.
(C) Bathtub and Shower Space. Receptacles shall not be installed within or
directly over a bathtub or shower stall.
(D) Protection for Floor Receptacles. Standpipes of floor receptacles shall allow
floor-cleaning equipment to be operated without damage to receptacles.
(E) Flush Mounting with Faceplate. The enclosure for a receptacle installed in an
outlet box flush-mounted in a finished surface shall be made weatherproof by
means of a weatherproof faceplate assembly that provides a watertight
connection between the plate and the finished surface.
4. (Q)We recently had a problem with the classification of a garage
that affected the wiring methods and ventilation requirements.
We were approaching the project as a minor garage and the
inspector turned us down saying it was a major repair garage.
(A)We hope to address this issue in plan review by requiring a statement
from the designer of record as to the classification. It could be that the
process was affected by incomplete info between the owner and his team as
to what the actual procedures of the garage would be. The job must be
installed for the correct usage as defined in the NEC.
511.2 Definitions.
Major Repair Garage. A building or portions of a building where major repairs,
such as engine overhauls, painting, body and fender work, and repairs that
require draining of the motor vehicle fuel tank are performed on motor vehicles,
including associated floor space used for offices, parking, or showrooms.
[30A:3.3.12.1]
Minor Repair Garage. A building or portions of a building used for lubrication,
inspection, and minor automotive maintenance work, such as engine tune-ups,
replacement of parts, fluid changes (e.g., oil, antifreeze, transmission fluid, brake
fluid, air-conditioning refrigerants), brake system repairs, tire rotation, and
similar routine maintenance work, including associated floor space used for
offices, parking, or showrooms. [30A:3.3.12.2]
5. (Q)What wiring methods are acceptable to run across roofs to
feed equipment located on the roof?
(A)We need to consider the conditions that are present and probable.
Per NEC 300.4 conductors are to be protected. Roofs of most commercial
buildings would allow for the system to be subject to physical damage and
possibly severe physical damage especially when re-roofed, and as such
acceptable wiring methods would be: (1) rigid conduit 334.10, (2) intermediate
conduit 342.10, (3) MI cable 332.10, (4) or the system could be put in other
raceways suitable for the environment and with other suitable physical protection
acting as a guard.
6. (Q) Explain what type of equipment is required to be listed and
labeled and how these requirements can be met. Example: A
machine shop has been in business for many years and has out
grown its’ present location. The owner of the machine shop builds a
new building and moves his existing equipment into the new
building and the electrical inspector will not final the building
because the machine shop equipment does not have a third party
label or listing. The owner states he has been using this equipment
for many years and feels the electrical contractor is responsible for
this problem.
(A)Per the General Statutes there are basically five methods to approve
equipment.
(1) The statutes allows the CEO to accept the listing of a NRTL, NEC 90.7
(2) The equipment could be wired to meet all the applicable NEC requirements
(3) The CEO could approve the equipment per his own authority NEC 110.2, but
most authorities would refer clients to acceptable NRTL field labeling services as
they were not trained or experienced in these types of evaluations
(4) The CEO can accept and approve the equipment per a certification report of
a registered professional engineer
(5) The owner can ask that the equipment be exempted per GS 143-138(b)
which exempts industrial machinery from inspections by code enforcement
officials
7. (Q) Are you required to provide arc-fault protection for an
outside flood light circuit, which has a 3-way wall switch control
in the bed room?
(A)No. The arc fault requirement applies only to outlets and the switch is a
device. NEC references are 210.12 and Article 100, definitions of outlet and
device.
8. (Q)Do temporary construction pole services require the new
“in use” covers for receptacles mentioned in NEC Section
406.8(B)?
(A)No. NEC 406.8 (B) (2) (b) states that for attended use for portable
equipment
that the only weatherproof cover required is one that is weatherproof when the
attachment plug is removed.
9. (Q)NEC Sections 110.10, 250.4(A)(5), the heading to Table
250.122 and a Note at the bottom of this Table, warn us that the
equipment grounding conductor shall be large enough to provide
a low impedance path so that in the event of a ground fault the
overcurrent device will operate to limit damage to the
equipment. How can the proper size be determined and how can
these sections be complied with by contractors and electricians
in the field?
(A)In most cases where the grounding system is in average condition the Table
250.122 will suffice. The next step for increased capability of the grounding
conductor is to size it equal to the current carrying conductors. Typically
without extreme conditions of length or excessive fault current the return path is
assured. In cases where distances of the return path are extremely long and the
fault current is excessive the contractors project engineer may need to run a
calculation to certify the grounding conductor’s capability. Additionally we need
to remember that per NEC 250.122 (B) that if we increase the phase conductors
for any reason that the grounding conductor shall be increased by the same
proportional circular mill area.
10. (Q)Distributors continue to market equipment in our state that
only has a CE mark of identification. They have sought help from
the Chamber of Commerce, and other public officials in forcing the
Inspection Departments to just accept this label. According to
them, CE is the same mark as any other “third party label” placed on
electrical equipment by a NRTL. After all, these are big companies
and expensive equipment and they say we are wrong in our
interpretation of third party listing and labeling and we are the
“ only State in the Union” requiring evaluation of equipment for
SAFETY . They insist there is no problem with unlisted equipment
and all manufacturers and distributors must be reputable and
would never sell a product in this country before it was rigorously
tested. As a contractor, what can we do when we encounter these
projects?
(A)Probably the best we can do is to attempt to educate our customers. The CE
label is not an indication of any nationally recognized testing lab. In their own
charter the label has no effect outside the chartered nations of Europe.
The NCBCC has not recognized the mark as an approved agency for NC. The
manufactures in the CE program do not participate in a jointly standardized
safety listing program and only guarantee their equipment’s safety by their own
claim. We also need to inform them of the exemption of industrial equipment
that was created by our General Assembly if applicable.
11. (Q)Several changes in the NEC have raised questions about the
disconnecting means on an outdoor generator being used to serve
as the disconnecting means for a building. Many Inspectors have
claimed that to allow those disconnects at the generator only, they
shall be rated for service and comply with NEC Article 225. Why are
we directed to NEC Article 225?
(A)225 is the feeder and branch circuit article. The conductors from the genset
are generally feeders per definition in Article 100. Per Article 90.3 the code
chapters 1 thru 4 applies to all installations where not amended by chapters 5
thru 7. Article 445 does not modify the requirements if the overcurrent device
is installed at the genset. However this question says disconnect and does not
specify overcurrent protection. 445.13 requires that the feeder now be sized for
115% of the rating of the genset output. There is an exception for this
requirement and if load conditions are controlled by design and operation to
prevent operation at more than 100%. Article 225 section II would tell
us how to deal with disconnect requirements at the building or structure.
225.36 states that the disconnect shall be rated for use as service equipment.
12. (Q)As a contractor we are mainly doing commercial work. We
install many 480/277-volt systems and know about the bonding
requirements when eccentric or concentric knockouts are
encountered. We maintain that as long as one end of the run meets
the requirements in NEC Article 250 we should not be concerned
about the other end when using metallic conduits such as rigid,
intermediate, and EMT, even though at the other end we have
concentric or eccentric knockouts. What is the interpretation of the
NEC ?
(A)NEC in 250.97 requires bonding of raceways for systems operating at over
250 volts. If concentric or eccentric knockouts are encountered we are to use
the methods specified in NEC 250.92 (B) except (B) (1). 250.96 (A) states
that metal raceways that serve as grounding conductors shall be effectively
bonded where necessary to ensure electrical continuity and the capacity to
conduct safely any fault current likely to be imposed on them. Additionally if the
raceway is being used as the grounding conductor 250.120 applies and states
that the grounding method shall be installed in accordance with the applicable
provisions of this code and 250.120 (A) requires using fittings approved for the
use and made tight with suitable tools. All of these references point to us that
both ends would need to be bonded.
13. (Q) Please explain to me how to size disconnecting means for
fire pumps. I ran a feeder from the service equipment panel over to
a disconnect beside the fire pump controller. The fire pump has a
FLA of 100-amperes. The Inspector is trying to make me install a
600-ampere disconnect. Why would he think I needed such a big
disconnect?
(A) Many installations we now see are feed from the utility directly to a listed
controller for a given horsepower motor. This installation depicts the one
additional overcurrent device that is allowed by NEC 695.4(B). NEC 695.4 (B)
(1) states that the overcurrent device shall be capable of carrying indefinitely
the locked rotor currents of the fire pump, maintenance pump and associated
equipment. The locked rotor requirement is the reason for the 600 amp
disconnect as the locked rotor current is generally six times the FLA of the
motor.
14.(Q)I have an industrial warehouse condominium in a single story
building divided into 20 tenants with 20 meters and 20 disconnect
switches (6 mains or less). I would like to install the entire
electrical service on a 6 feet high concrete wall which is
approximately 20 feet long and located 6 feet away from the main
building. Since the wall is not part of the building, is this an
allowable installation or would this wall have to be connected to the
main building such that it were considered part of the building?
(A)First I believe we need to look in Article 100 at the definition of structure.
It states, that which is built or constructed. The installation is allowable but
requires that we now have to set a disconnect means at the entrance to the
building per NEC 225.30, 31, and 32. Additionally we would have to reground
at the building per NEC 250.32. I don’t believe that is what the author of the
question desires to do. If the wall where made to be part of the building
(generally in or on the footprint) then the price of the additional disconnects and
grounding could be eliminated.
15. (Q)An electrical contractor has mounted a panelboard with the
main installed vertically to one end. It seems though that the
handle is now upside down. You must move the handle down to
turn on the power and up to turn it off. To me this is in violation of
the NEC . What is your interpretation?
Yes it’s a violation per the NEC 404.7 Indicating.
General-use and motor-circuit switches, circuit breakers, and molded case
switches, where mounted in an enclosure as described in 404.3, shall clearly
indicate whether they are in the open (off) or closed (on) position.
Where these switch or circuit breaker handles are operated vertically rather
than rotationally or horizontally, the up position of the handle shall be the
(on) position.
Exception No. 1: Vertically operated double-throw switches shall be permitted to
be in the closed (on) position with the handle in either the up or
down position.
Exception No. 2: On busway installations, tap switches employing a centerpivoting handle shall be permitted to be open or closed with either
end of the handle in the up or down position. The switch position
shall be clearly indicating and shall be visible from the floor or from
the usual point of operation.
16. (Q)I’m wiring a machine shop where the equipment is located in
a generally open area. The only way to wire this equipment is from
the bar joists to the equipment disconnect switch. I ran IMC with
threaded couplings from a junction box on the bar joist to the
disconnect. The Inspector says I have to support the conduit better.
How do I do that, it is going to cost too much to add braces?
(A)NEC 342.30 allows for this type installation in (B) (3)
Exposed vertical risers from industrial machinery or fixed equipment shall be
permitted to be supported at intervals not exceeding 6 m (20 ft) if the conduit is
made up with threaded couplings, the conduit is supported and securely
fastened at the top and bottom of the riser, and no other means of intermediate
support is readily available.
17. (Q)If a single family residence has a single receptacle on its
exterior for a water softener or chemical pump and it is a 120-volt,
15-ampere or 20-ampere, would this receptacle be acceptable as
the one required for servicing the A/C equipment if it is within 20
feet of the A/C Unit?
(A)NEC 210.63 requires an outlet for servicing the a/c units. It must be within
25 feet, on the same level, not on the load side of the disconnect means; and
GFCI protected per NEC 210.8. The code does not require a dedicated circuit
and therefore the outlet could be on the same circuit as the equipment as long
as it does not violate the requirements of NEC 210.23 .
18.(Q)Is it permissible to use UF cable for interior wiring method
instead of NM cable?
(A)NEC 340.10 (4) allows this use;
(4)
Installed as nonmetallic-sheathed cable. Where so installed, the
installation and conductor requirements shall comply with Parts II and III of
Article 334 and shall be of the multiconductor type.
EVENTS UPDATE
•
The re-org has been approved by the executive management team and
we expect to implement by sometime in January