MECKLENBURG COUNTY
Land Use and Environmental Services Agency
Code Enforcement
2015 August Consistency Questions/Topics
a. Customer Service Discussion
b. CMS units, modular labels needed
c. Q & A
1. I have a project in plan review showing a 480v
generator w/disc. on the outside of the building,
it feeds a step down transformer 480delta/208y
then to a disc. on the secondary side of the
transformer, then a 3 pole transfer switch before
it enters the building where the service
equipment main is located. All grounding takes
place at the transfer switch. Does this require a
service disconnect ahead of the transfer on the
utility side? How should the transformer ground
be treated? -BARNES
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We will need service ocp adjacent to the transfer
switch (NEC 230.91) and GEC will be
established at the point of service as allowed
(NEC 250.24 (A) (1)). The transformer ground
can be tied into the GEC at service or can be
bonded at transfer switch (NEC 250.30).
2. Can I support MC cable off of EMT? - DELLINGER
NO. Not if both carry nominal voltages (NEC
300.11 (B)). There are limited exceptions.
3. I ran my GEC from the transformer to the
building steel in EMT - the inspector made me
bond both ends of the EMT - was she correct? HARTMAN
Yes, the inspector is correct! NEC 250.64 (E) has
the answer and requires both ends to be
addressed.
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4. Do all residential sewer lift stations need
separate permits pulled or can it be listed on the
house permit? -KING
A permit can cover whatever the scope of the
work is as shown on the plans or documentation
if issued correctly.
5. Where does it say I have to have 2 circuits for
these pumps? - MULLIS
The plumbing code in 712.3.4.1 requires the
alarm and pump to be on different circuits.
6. On a mini-split system, do you need a
disconnecting means within sight of the inside
unit? – WEST
Yes. Look at NEC 422.30 and 31(C) for
requirements when over 1/8th hp. If the units
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have a compressor and individual multiple fan
units see 430.102(B) (2) Excp. 2.
7. When using the service mast as a support,
230.28 states "it shall be of adequate strength."
Does this mean IMC or rigid and what would be
the minimum size required? - MULLIS
Per power company regs, rigid 2” is required.
The county agrees with this standard.
8. I'm changing out a residential sub panel to a
larger one for the new loads on an addition. The
only place I can put this panel is in a closet or in
the stairway. Is either of these places
acceptable? - BARNES
NEC 240.24 controls the location. Clothing
closets and bathrooms are not permissible.
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Stairways could be used on a landing that meets
the working clearances of 110.26.
9. I was turned down the other day for not using a
torque wrench on my 1200 amp OCP in my main
switchboard. I tightened the lugs with a 2 ft.
cheater bar on my 3/4 drive wrench! So what
was the problem? - DELLINGER
The contractor has this responsibility. A tug test
is all we as inspectors have ever employed. We
will not assume liability for correct torque.
10. While trenching a ditch I cut a #8 USE cable. The
inspector turned me down and stated that I
needed a splice box to repair this wire. I used a
split bolt and taped the joint, then split a plastic
drink bottle. I put this joint inside the bottle and
filled the bottle with black tar. Why wasn't this
acceptable as per 300.50 D? - HARTMAN
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You must use the listed products intended for this
application (NEC 110.3).
11. A. When an Isolated Ground Receptacle as
described in NEC 406.3(D) are used in a
commercial kitchen as described in NEC Art.100
under “kitchen” are they required to meet the
requirements of NEC 210.8(B)(2)? - KING
Yes. Some coolers are being found w/o
compliance in the grocery stores. The key here is
the definition of a kitchen.
B. What if they supply power to monitors and
are mounted at ceiling level?
Yes!
C. What if they supply power to POS equipment
and are mounted underneath the counters or
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inside cabinets that are not accessible to
utilize for other equipment?
Yes!
12. A service equipment panelboard has a 400amp
main which feeds a bus that has double barrel
lugs at the bottom, and then feeds two 200 amp
disconnects. Is it permissible to tap directly from
the double barrel lugs of a service equipment
panelboard? - KING
Yes as long as we meet NEC 240.21 and 250.122
(G) and 110.3.
13. I am reviewing plans for an apartment building.
Disconnects for the A/C units are located behind
condenser with about 2’ of clearance. (A) Are
these disconnects required to the meet
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requirements of 110.26? (B) Does it make a
difference if they are fused or non-fused? - WEST
No, they do not require servicing while
energized. They must however be readily
accessible if unfused (NEC 404.8) and readily
accessible (NEC 240.24) if they contain OCP.
These switches additionally have to meet 404.14
(A) (3).
14. Are GFCI receptacles at the rear of commercial
cooking equipment, mounted strictly for the
ignition of the gas appliance, considered readily
accessible? The appliances are on casters and
supplied with lanyards to allow movement for
cleaning and accessing the back of the units? MULLIS
In this case it seems the GFCI unit is accessible.
See NEC 422.16 (A) (2). As long as we can
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easily access the unit for test we are fine. We
need to always look for the way to pass a job.
The skill here is trusting our own good judgment.
15. Explain the vocabulary difference in grounding
and bonding (Had one inspector approach me
with this because of turn down and notes were
confusing because wrong vocabulary was used). BARNES
Bonded (Bonding). Connected to establish
electrical continuity and conductivity.
Basically bonding is done to assure a continual
fault current path on all metallic components.
Grounding Conductor, Equipment (EGC). The
conductive path(s) installed to connect normally
non–current-carrying metal parts of equipment
together and to the system grounded conductor or
to the grounding electrode conductor, or both.
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Grounding is a backup system to operate ocp in
the event the grounded conductor is interrupted or
nonexistent.
Grounded Conductor. A system or circuit
conductor that is intentionally grounded.
From Soares
a) Ground; The earth
b) Grounded (Grounding); Connected to Ground
or a conductive body that extends to ground
c) Grounded Conductor; A system or circuit
conductor that is intentionally grounded
16. Is romex allowed to be used between the floor
of a 2 story screen porch that has a roof on 2nd
story and the floor is covered in rubber lining.
The roof of the first level is covered with wood.
So basically the romex is concealed. - DELLINGER
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With it totally concealed from the weather we
don’t see an issue per NEC 334.10.
17. Can Metallic cable be run in a carport, with
open walls? – HARTMAN
Perhaps. 330.10 and 330.12 qualify how it is to
be used. This would depend on the specific
location. Is it a wet location? Is it a position
where it needs to be sunlight resistant? Is it
going to be exposed to corrosion? Is it exposed to
physical damage? Judgment would need to be
used in determining the specific applicable
conditions.
18. On a final electrical inspection, does the smoke
alarm control wire, need to be terminated in the
A/H unit, when a dynamic damper is not used? KING
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Perhaps. If required for separation requirements
for building and mechanical purposes it needs to
be connected. This would need to be established
with the mechanical inspector if not established
on the plans details.
19. When considering clearance issues for large
equipment, what does unobstructed egress
mean? - HARTMAN
NEC 110.26 (C) (2) gives us the requirements for
large equipment. The two considerations for
qualifying are 1200 amps and over six feet wide.
The extra requirements are for worker safety in
case of an incident causing uncontained arcing.
The concern is always allowing the worker clear
access to escape the fault explosion and get to a
safe area. Basically there may be no physical or
arc fault zone interrupting the egress path.
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20. Is a baptism pool or cleansing pool covered by
NEC 680? - WEST
680.1 Scope. The provisions of this article apply to the
construction and installation of electrical wiring for, and equipment in or
adjacent to, all swimming, wading, thera- peutic, and decorative pools;
fountains; hot tubs; spas; and hydromassage bathtubs, whether permanently
installed or storable, and to metallic auxiliary equipment, such as pumps,
filters, and similar equipment. The term body of water used throughout Part
I applies to all bodies of water covered in this scope unless otherwise
amended.
While we have in the past required installations
to meet Art. 680 as much as possible the answer
is NO per NCDOI Mr. Ron Chilton and strictly
code.
21. Can I have a service at the house and a circuit
from the garage service to control lighting? MULLIS
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Yes. See 225.30 (D). Also this would have to be
identified per NEC 225.37.
22. Do all sub panels require main ocp? - BARNES
The code generally requires ocp per NEC
408.36. Exceptions are allowed. When feeding
different buildings or structures be sure to use
other applicable references.
23. What parameters determine whether a recess
light in a shower would have to be rated for a
damp location or a wet location? - DELLINGER
Per 410.10 D; Luminaires located within the
actual outside dimension of the bathtub or shower
to a height of 2.5 m (8 ft.) vertically from the top
of the bathtub rim or shower threshold shall be
marked for damp locations, or marked for wet
locations where subject to shower spray.
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Each installation would have to be individually
looked at with regard to shower spray. Generally
it would seem that if the shower was a normal
down flow head a 9’ ceiling would be out of the
spray range.
24. Would a smoke detector be counted as a device
when calculating box fill? - HARTMAN
Not normally. NEC 314.16 shows no specific
requirement for the smoke detector. B 4 does
mention yoke or strap containing one or more
devices or equipment. Typically the smoke
detector does not mount inside the box and
should not be included for fill count.
25. I was recently turned down on a ceiling
inspection because I had installed smoke
detectors and strobes and the inspector stated
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he could not see the grommets. Is this correct? KING
The inspector needs to see the rough in of the
system w/o the devices installed. It is at that point
he can judge the condition of the box and
cables/conductors.
26. Is aircraft cable acceptable for supporting 2x4
fixtures? - DELLINGER
If it meets or exceeds the strength of the #9
ceiling wire we would be fine.
d. Service questions review;
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A. HOW TO QUALIFY ADDITIONAL SERVICES ON
BUILDING?
230.2 Number of Services. A building or other
structure served shall be supplied by only one
service unless permitted in 230.2(A) through (D).
For the purpose of 230.40, Exception No. 2 only,
underground sets of conductors, 1/0 AWG and
larger, running to the same location and connected
together at their supply end but not connected
together at their load end shall be considered to be
supplying one service.
(A) Special Conditions. Additional services shall be
permitted to supply the following:
(1) Fire pumps
(2) Emergency systems
(3) Legally required standby systems
(4) Optional standby systems
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(5) Parallel power production systems
(6) Systems designed for connection to multiple
sources of supply for the purpose of enhanced
reliability
Section 230.2(A) is fairly straightforward and
generally needs no further interpretation. Other
code sections may apply specifically to them.
(B) Special Occupancies. By special permission,
additional services shall be permitted for either of
the following:
(1) Multiple-occupancy buildings where there is no
available space for service equipment accessible to
all occupants
Section 230.2(B)(1) for decades has been
permitted in Mecklenburg County as a matter
of policy without written special permission
for every project, provided all the
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requirements for the installation of a single
service were met for each additional service,
and that all the mains were inside each given
tenant space inside the building or structure.
Where mains are grouped in the same
location, either inside or outside the building
or structure, we fall back to the other rules of
section 230.2 to qualify for additional services
and at the same time adhere to the policy that
all mains are either inside or outside for a
given building or structure. Section 230.2(B) (1)
really doesn’t apply here because when they
are grouped in one location all tenants must
have access to their overcurrent protection,
and this installation suggests just that.
Where a second service is allowed under
230.2(B) (1) the second service must be located
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a minimum of 50’ away from the first and
other services. All proper service identification
labeling must be done.
An additional service for a house panel must
go through the same qualifications per section
230.2 as any other service. A house panel is an
exception to the “all mains in or out” policy in
that if all mains were inside, we have allowed
the house panel to be outside per the
requirements of section 230.40 exception 4
and section 210.25. Please note that this is not
permission for another service just because
there is a need for a house panel nor is it
permission to add a seventh main disconnect
where you already have six.
(2) A single building or other structure sufficiently
large to make two or more services necessary.
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To allow an additional service per section
230.2(B) (2) a contractor or designer must
show how, per the size of the building or
structure served, more than one service is
permitted. The typical rule of thumb for this
allowance is to show a 5% or greater voltage
drop feeder calculation based on the location
of the first service to another given point of
the building or structure.
(C) Capacity Requirements. Additional services shall
be permitted under any of the following:
(1) Where the capacity requirements are in excess
of 2000 amperes at a supply voltage of 600 volts or
less
According to section 230.2(C)(1) when you
have a load calculated in accordance with
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Article 220 and that load exceeds 2000 amps
you may have a second service and for
multiples of 2000 thereafter an additional
service. All proper service identification
labeling must be done.
(2) Where the load requirements of a single-phase
installation are greater than the serving agency
normally supplies through one service.
When a section 230.2(C) (2) allowance is
requested the contractor or designer must
provide evidence from the serving utility that
they indeed can’t meet the serving
requirements for a SINGLE PHASE SERVICE.
Please note that this section does not address
three phase services.
(3) By special permission
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Case by case judgment. Must for some
unforeseen reason not be able to be satisfied
by other rules. Aligns with Admin. Code,
Alternate Methods and Means
(D) Different Characteristics. Additional services
shall be permitted for different voltages,
frequencies, or phases, or for different uses, such as
for different rate schedules.
This section is also fairly straightforward.
Voltages used in the code are further defined
in section 220.5 as follows: “nominal system
voltages of 120, 120/240, 208Y/120, 240, 347,
480Y/277, 480, 600Y/347, and 600 volts shall
be used.”
B. HOW TO APPLY 230.40 EXCEPTION NO 2
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IV. Service-Entrance Conductors
230.40 Number of Service-Entrance Conductor
Sets.
Each service drop, set of overhead service
conductors, set of underground service conductors,
or service lateral shall supply only one set of
service-entrance conductors.
Exception No. 2: Where two to six service
disconnecting means in separate enclosures are
grouped at one location and supply separate loads
from one service drop, set of overhead service
conductors, set of underground service conductors,
or service lateral, one set of service-entrance
conductors shall be permitted to supply each or
several such service equipment enclosures.
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One service drop supplying maximum of six service
equipment enclosures grouped at one location.
For the purpose of 230.40, Exception No. 2 only,
underground sets of conductors, 1/0 AWG and
larger, running to the same location and connected
together at their supply end but not connected
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together at their load end shall be considered to be
supplying one service.
One service lateral consisting of six sets of
conductors 1/0 AWG or larger, terminating in a
single service equipment enclosure with maximum
of six service disconnecting means.
C. Definitions
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Service. The conductors and equipment for
delivering electric energy from the serving utility to
the wiring system of the premises served.
Service Cable. Service conductors made up in the
form of a cable.
Service Conductors. The conductors from the
service point to the service disconnecting means.
Service Conductors, Overhead. The overhead
conductors between the service point and the first
point of connection to the service-entrance
conductors at the building or other structure.
Service Conductors, Underground. The
underground conductors between the service point
and the first point of connection to the service27
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entrance conductors in a terminal box, meter, or
other enclosure, inside or outside the building wall.
Informational Note: Where there is no terminal
box, meter, or other enclosure, the point of
connection is considered to be the point of
entrance of the service conductors into the
building.
Service Drop. The overhead conductors between
the utility electric supply system and the service
point.
Service-Entrance Conductors, Overhead System.
The service conductors between the terminals of
the service equipment and a point usually outside
the building, clear of building walls, where joined by
tap or splice to the service drop or overhead service
conductors.
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Service-Entrance Conductors, Underground
System. The service conductors between the
terminals of the service equipment and the point of
connection to the service lateral or underground
service conductors.
Informational Note: Where service equipment is
located outside the building walls, there may be no
service entrance conductors or they may be entirely
outside the building.
Service Equipment. The necessary equipment,
usually consisting of a circuit breaker(s) or
switch(es) and fuse(s) and their accessories,
connected to the load end of service conductors to
a building or other structure, or an otherwise
designated area, and intended to constitute the
main control and cutoff of the supply.
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Service Lateral. The underground conductors
between the utility electric supply system and the
service point.
Service Point. The point of connection between the
facilities of the serving utility and the premises
wiring.
Informational Note: The service point can be
described as the point of demarcation between
where the serving utility ends and the premises
wiring begins. The serving utility generally specifies
the location of the service point based on the
conditions of service.
Q-1. WE HAVE A 277/480 AND 120/208 SERVICE
LOCATED AT THE SAME LOCATION BOTH HAVE
ONLY SIX DISCONNECTS CAN WE ALLOW THIS?
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VI. Service Equipment — Disconnecting Means
230.70 General. Means shall be provided to
disconnect all conductors in a building or other
structure from the service entrance conductors.
230.71 Maximum Number of Disconnects.
(A) General. The service disconnecting means for
each service permitted by 230.2, or for each set of
service-entrance conductors permitted by 230.40,
Exception No. 1, 3, 4, or 5, shall consist of not more
than six switches or sets of circuit breakers, or a
combination of not more than six switches and sets
of circuit breakers, mounted in a single enclosure, in
group of separate enclosures, or in or on a
switchboard. There shall be not more than six sets
of disconnects per service grouped in any one
location.
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For the purpose of this section, disconnecting
means installed as part of listed equipment and
used solely for the following shall not be considered
a service disconnecting means:
(1) Power monitoring equipment
(2) Surge-protective device(s)
(3) Control circuit of the ground-fault protection
system
(4) Power-operable service disconnecting means
A-1. Yes and no?
If you qualify for a second service of differing
characteristics or for over 2k amps or over normal
delivery for a single phase size, the location is not
restricted to 50’ separation.
If you are using the multiple occupancy
method the 50’ separation comes in from our
“Special Permission”. All proper service
identification labeling must be done.
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