NEC Commercial Electrical Practice Test

What must be done to ungrounded conductors in a multi-wire branch circuit when accessible?

1. They should be painted a bright color

2. They must be covered with insulating tape

3. They need to be identified and labeled

4. They can remain unmarked

The correct answer is: They need to be identified and labeled

In a multi-wire branch circuit, ungrounded conductors must be identified and labeled to ensure safety and proper functioning of the electrical system. This requirement is crucial because it helps anyone who interacts with the circuit to understand which conductors are live and which are not. Proper identification reduces the risk of accidental shock or short circuits during maintenance or modifications, as it allows for clear communication about the circuit's components. Labeling provides an immediate visual cue, facilitating easier troubleshooting and reducing the likelihood of errors during electrical work. It is aligned with the NEC (National Electrical Code) requirements, which emphasize the importance of safety in electrical installations. Properly identified conductors contribute to the overall safety and reliability of the electrical system. While other options may seem like viable alternatives, they do not fulfill the NEC's emphasis on clear identification of conductors in order to maintain safety standards in electrical work.