Code Reference
ElectricalNEC 2023

Section 200.6/Neutral Conductor Identification

NEC 200.6 requires grounded (neutral) conductors to be identified by specific color coding, ensuring they are distinguishable from ungrounded conductors.

What this section requires

Grounded (neutral) conductors 6 AWG or smaller must be identified by a continuous white or gray outer finish, or by three continuous white or gray stripes along the conductor length. For conductors larger than 6 AWG, identification must be by a continuous white or gray outer finish, by three continuous white or gray stripes, or at the time of installation by a distinctive white or gray marking at each termination point.

Why this section exists

Correct identification of the neutral conductor is essential for safety during installation, maintenance, and troubleshooting. A neutral conductor that is mistaken for an ungrounded (hot) conductor, or vice versa, can result in shock hazards, improper circuit operation, and equipment damage. The color coding system ensures that electricians can quickly and reliably identify the neutral in any wiring installation.

What plan reviewers look for

Plan reviewers check that the conductor color schedule or wiring notes on the drawings specify the neutral conductor identification method. For three-phase systems with multiple voltage levels, the reviewer verifies that the neutral identification method distinguishes between different voltage systems. The reviewer also checks that the riser diagram and panel schedules are consistent in their neutral conductor callouts.

Common violations

No conductor color schedule on drawings
The electrical drawings do not include a wiring color code legend or conductor identification schedule. Without this, there is no documented standard for the project and the reviewer cannot verify neutral identification compliance.
Same neutral identification for multiple voltage systems
A building with both 480/277V and 208/120V systems uses the same white neutral identification for both. The NEC requires a means to distinguish grounded conductors of different systems where they are present in the same raceway, enclosure, or equipment.
Compliance tip
Include a conductor color schedule in the electrical general notes that specifies the identification method for every conductor type: ungrounded (hot) conductors by phase, grounded (neutral) conductors by voltage system, and equipment grounding conductors. For buildings with multiple voltage levels, use different neutral colors or marking methods for each system.

Related NEC requirements

Section 200.7 covers the use of the white or gray conductor and the conditions under which a white conductor may be used as an ungrounded conductor. Section 210.4 addresses multiwire branch circuits where neutral identification is critical. Section 250.119 covers equipment grounding conductor identification.

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Related sections

210.4Multiwire Branch CircuitsNEC 2023310.16Conductor Ampacity TableNEC 2023