An ungrounded conductor from the branch circuit must be identified at all termination points if it is supplied from what?

• A. More than one nominal voltage system
• B. Only a single voltage
• C. A different grounding system
• D. A temporary wiring method

Answer: (A)

When a branch-circuit ungrounded conductor could be fed from more than one nominal voltage system, you must identify it at every termination point. The reason is that different voltage systems establish different potential references to ground, and the same conductor could carry different voltages depending on which system is in use. Clear labeling at each termination prevents confusion, reduces the risk of misidentifying the conductor during maintenance or re-energizing, and ensures safe disconnection and wiring across the different voltage supplies. If only a single nominal voltage is involved, that conflict in voltage references doesn’t arise, so labeling at every termination isn’t mandated by this rule. The presence of a different grounding system or temporary wiring method doesn’t by itself create the same need for multi-system identification; the critical factor is the circuit being fed from more than one voltage system.