NEC: Identification Requirements for Branch Circuits, Part 2

What color is the grounded conductor? If you answered “white,” you’re partially correct. A continuous white outer finish is one way we identify the grounded conductor [200.6]. Do you know of any other approved methods of identification?

In addition to white, the grounded conductor can also be identified by these other two methods:

• Continuous gray finish.
• Three continuous white or gray stripes along the conductor’s entire length on other than green insulation (the grounded conductor can’t be green, to avoid confusing it with a grounding conductor).

And if the conductor is 4 AWG or larger, you have a fourth method available: you can identify it as the grounded conductor by encircling it with a distinctive white or gray marking at its terminations.

If the conductor is 6 AWG or smaller, you can use any of those first three methods or:

• White or gray outer covering, colored tracer threads (in the braid) identifying the source of manufacture.
• Distinctive markings at termination of Type MI cable.
• Distinctive white markings at all terminations if a PV system cable complying with Sec. 690.31.
• Fixture wire complying with Sec. 402.8.
• Aerial cable complying with any of the other identification requirements in Sec. 200.6(A)(1) through (7) or by means of an identification ridge on the exterior of the cable.

Also, it’s a good design practice to use as few of these methods as possible in a given installation.