Per 200.7(C)(1), where the white or gray conductor of a cable assembly is used as a switch loop for circuits of 50 volts or more, the switch loop must be permanently reidentified as an ungrounded conductor by what method?

• A. Marking tape, painting, or other effective means of a color other than white, gray, or green
• B. Labeling with switch loop
• C. Using red insulation
• D. Installing a ground wire

Answer: (A)

When a neutral (white) or other commonly identified conductor is repurposed as a switch loop for circuits of 50 volts or more, it no longer functions as a neutral or grounded conductor. To prevent dangerous confusion, the code requires permanent reidentification so anyone working with the circuit recognizes it as ungrounded. The approved way to do this is by marking tape, painting, or another effective method that shows a color different from white, gray, or green. This makes the conductor’s hot status obvious and reduces the risk of accidental contact with what could be mistaken for a neutral or grounded conductor.

Labeling with “switch loop” doesn’t satisfy the reidentification requirement. Simply using red insulation isn’t guaranteed to meet the intent unless it’s part of a compliant marking or painting method. Installing a ground wire doesn’t address the need to clearly identify the conductor as a hot one.