MECKLENBURG COUNTY
Land Use and Environmental Service Agency
Code Enforcement
Electrical Consistency Meeting December 20th, 2009
Code Consistency Questions
1. 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?
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.
2. 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.
3. 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?
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.
4. 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?
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 .
5. Is it permissible to use UF cable for interior wiring method instead
of NM cable?
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.
6. Can I hard wire an electric-discharge luminaire to a junction box
using flexible cord?
No, NEC 410.62 (C) 1 (1) and (2) describe the method of installation required.
C) Electric-Discharge Luminaires.
(1) Cord-Connected Installation. A luminaire or a listed assembly shall be
permitted to be cord connected if the following conditions apply:
(1)
The luminaire is located directly below the outlet or busway.
(2)
The flexible cord meets all the following:
a.
Is visible for its entire length outside the luminaire
b.
Is not subject to strain or physical damage
c.
Is terminated in a grounding-type attachment plug cap or busway plug, or
is a part of a listed assembly incorporating a manufactured wiring system
connector in accordance with 604.6(C), or has a luminaire assembly with a strain
relief and canopy having a maximum 152 mm (6 in.) long section of raceway for
attachment to an outlet box above a suspended ceiling.
However if it is an adjustable electric-discharge luminaire the 410.62 (B) allows
the installation without cord cap. (Code Panel 18)
7. I am working with a client that has multiple pieces of industrial
equipment they want to have exempted. Is there a standard form for
listing the equipment? Can they submit one request with multiple
pieces of equipment listed for exemption?
There is no standard form, and yes you can have multiple pieces on one request.
We need to know what product is being produced (product-in…product-out), and
we need electrical nameplate data from each piece of equipment along with the
data mentioned on our website. Any cut sheets, specs, pictures etc. are a plus.
Please include the project name, address, and electrical permit number in the
letter. Also note that we need to see the equipment installed before any final
decision is made.
8. Are service receptacles required on the same level and within 25 feet
of heating and air-conditioning equipment (electric duct heaters, VAV
units and the like) installed in hollow spaces above suspended ceilings
in commercial buildings? Will a general purpose receptacle located on
the wall (18 inches AFF nominal) in the space below and within 25 feet
of mechanical equipment installed in hollow spaces above suspended
ceilings in commercial buildings meet the intent of the NEC ?
Yes and Yes per NEC 210.63. The word level is the key, level equates to floor
level (as in a multi floor building) and if in the required 25’, all is well.
210.63 Heating, Air-Conditioning, and Refrigeration Equipment Outlet.
A 125-volt, single-phase, 15- or 20-ampere-rated receptacle outlet shall be
installed at an accessible location for the servicing of heating, air-conditioning,
and refrigeration equipment. The receptacle shall be located on the same level
and within 7.5 m (25 ft) of the heating, air-conditioning, and refrigeration
equipment. The receptacle outlet shall not be connected to the load side of the
equipment disconnecting means.
Exception: A receptacle outlet shall not be required at one- and two-family
dwellings for the service of evaporative coolers.
EVENTS & UPDATES
1) NCBCC, DECEMBER 10 MTG. - HAD AGENDA ITEM FOR ADOPTION OF 2009
IRC AS 2012 NC RESIDENTIAL CODE, SMOKE DETECTOR RULES PROPOSED TO
CHANGE, INSPECTION ACCESS CHANGE PROPOSED TO CHANGE
2) PER DUKE ANY SELF CONTAINED METER SERVICE WILL BE LIMITED TO
10000 AIC
3) FIRE PUMP ISSUES; WE’RE STILL AWAITING NCDOI INPUT
4) ELECTRIC VEHICLE CHARGING
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