20 ELECTRICALCONTRACTOR | APR. 16 | WWW.ECMAG.COM
CODEFAQS BY JIM DOLLARD
Some local jurisdictions in our area
have required type AC/MC cable to be
marked externally with a color code to
identify as high-voltage 480/277-volt
(V) or low-voltage 240/120V. I have seen
industry-wide identification of fire alarm
AC cable (externally identified “red”)
but not branch circuits. Is this being
addressed currently, or will it become
a requirement? If we use cable marked
externally with a color code, are we
permitted to re-identify the conductors if
needed to comply with 210.5(C)( 1)?
The NEC does not require identification
marking on the outside of cable assemblies or raceways to identify the color or
conductor voltage within. I am not aware
of any action to require such markings.
If the NEC were to go down that road, it
would be necessary to include all cable
assemblies and raceways.
The manufacturers of metal-jacketed
cable assemblies offer many variations
to suit individual installation needs. One
option is marking the outer jacket with
colors to identify the colors of the conductors in the cable and voltages. While
the NEC does not contain a required color
code for voltage marking, the industry
standard is 208/120V (A) black, (B) red,
(C) blue and grounded/neutral white;
480/277V (A) brown, (B) orange, (C)
yellow and grounded/neutral gray. Manufacturers may mark the cable assembly
outer jacket to identify the conductor colors inside the cable based on the number
of conductors in the cable. For example, a
four-wire, multiwire branch circuit may
be marked with all of the associated colors while a two-wire branch circuit may
be marked as blue and white for 120V or
yellow and gray for 277V.
Section 210.5(C)( 1) requires multi-
wire branch circuits to be marked at
termination, connection and splice
points. The intention is to identify the
voltage where there is more than one
nominal voltage system in the build-
ing, such as having both 208/120V and
480/277V systems. Using color-coded
cable assemblies helps the installer
comply with 210.5(C)( 1) because the
conductors within are easily identifiable
by color. However, color-coding the out-
side of a wiring method is not an NEC
requirement. The Code permits the use
of marking tape on conductors at termi-
nations, connections and splice points
[see 210.5(C)( 1)(a)].
Some manufacturers identify voltage
levels with color coding in their literature. This has led to confusion where an
inspector may reject re-identification
of a color-coded cable assembly and
base the rejection on Section 110.3(B).
I understand the inspector’s reasoning, and in my opinion, the NEC needs
to address this. However, we must fully
understand that 110.3(B) requires installation in accordance with the product
“listing and labeling.” For example, the
UL White Book identifies Type MC as
“PJAZ,” and there are no limitations or
prohibitions in the listing for conductor re-identification. In addition, I have
never seen Type MC cable labeled with
a prohibition on conductor re-identification. Local requirements as mentioned in
your question may take precedence over
the NEC and prohibit re-identification.
Are tamper-resistant ( TR) receptacles
required in K– 8 schools?
No. TR receptacle requirements in the
2014 NEC are limited to dwelling units,
guest rooms/suites in hotels/motels, and
childcare facilities. There are changes on
the way for the 2017 NEC (if they make
it through the NFPA process) to add
preschools; elementary schools; areas in
medical, dental and outpatient facilities;
and some assembly occupancies.
Is self-certification acceptable?
I am aware that the NEC requires lighting
fixtures to be listed. We do retail work
that includes restaurants and specialty
stores where it is common for the owner
to supply some or all of the lighting
fixtures. For that reason, we clearly state
in our contract that all owner-supplied
lighting fixtures must be listed, or we
will not install them. An owner recently
supplied us with manufacturer literature
for custom, 120V, pendant-type fixtures,
and the literature states the fixtures
“meet the applicable UL standard
for luminaires.” Is this acceptable?
Should the inspector recognize the
manufacturer literature as compliance
with the listing requirement?
A manufacturer’s statement on a carton/
box, instructions or any type of literature
that meets an applicable standard does
not mean the product is listed. A product will only be recognized as “listed”
where it bears the listing agency’s mark
and any other markings that the applicable product standard requires. Where
the NEC requires equipment to be listed,
manufacturer or owner self-certification
in lieu of third-party product listing does
not comply with applicable NEC requirements. It is a good practice to inform
owners that supply their own equipment that only listed luminaires will be
installed and that manufacturer or owner
self declaration does not equate to listing.
Grounded conductor terminations
Why does the NEC not permit more than
one neutral conductor under a single
screw on a terminal block that clearly
permits more than one conductor to be
terminated under a single screw?
The requirement that you are referring to applies only to panelboards.
Section 408.41 is located in “Part III
Panelboards” of Article 408, and the
general rule clearly prohibits terminat-
Jim Dollard has an extensive background in codes and standards. If you have a query about the National
Electrical Code (NEC), Jim will help you solve it. Questions can be sent to email@example.com. Answers
are based on the 2014 NEC.