210.5 Identification for Branch Circuits.
(A) Grounded Conductor. The grounded conductor of a
branch circuit shall be identified in accordance with 200.6.
(B) Equipment Grounding Conductor. The equipment
grounding conductor shall be identified in accordance with
250.119.
(C) Identification of Ungrounded Conductors. Ungrounded
conductors shall be identified in accordance with 210.5(C)(1)
or (2), as applicable.
(1) Branch Circuits Supplied from More Than One Nominal
Voltage System. Where the premises wiring system has branch
circuits supplied from more than one nominal voltage system,
each ungrounded conductor of a branch circuit shall be identified
by phase or line and system at all termination, connection,
and splice points in compliance with 210.5(C)(1)(a) and (b).
(a) Means of Identification. The means of identification
shall be permitted to be by separate color coding, marking
tape, tagging, or other approved means.
(b) Posting of Identification Means. The method utilized
for conductors originating within each branch-circuit panelboard
or similar branch-circuit distribution equipment shall be
documented in a manner that is readily available or shall be
permanently posted at each branch-circuit panelboard or similar
branch-circuit distribution equipment. The label shall be of
sufficient durability to withstand the environment involved and
shall not be handwritten.
Exception: In existing installations where a voltage system(s) already
exists and a different voltage system is being added, it shall be permissible
to mark only the new system voltage. Existing unidentified systems
shall not be required to be identified at each termination, connection,
and splice point in compliance with 210.5(C)(1)(a) and (b). Labeling
shall be required at each voltage system distribution equipment to identify
that only one voltage system has been marked for a new system(s).
The new system label(s) shall include the words “other unidentified
systems exist on the premises.”
