The ground-fault protection function requires opening which conductors of the faulted circuit?

The ground-fault protection function requires opening which conductors of the faulted circuit?

• A. All ungrounded conductors
• B. The neutral conductor only
• C. All grounded conductors
• D. The equipment grounding conductor only

Answer: (A)

When a ground fault occurs, the current is carried by the ungrounded (live) conductors. Ground-fault protection is designed to rapidly remove power from the faulted circuit by opening all of the conductors that could supply that fault current. Those are the ungrounded conductors. The neutral and the equipment grounding conductor are grounded or serve as safety paths, and they are not the conductors that need to be interrupted to clear the fault. If you only opened the neutral or only the equipment grounding conductor, the energized ungrounded conductors could still supply fault current and the fault would not be cleared. Opening all ungrounded conductors ensures the fault current has no supply path and the circuit can be safely de-energized.

When a ground fault occurs, the current is carried by the ungrounded (live) conductors. Ground-fault protection is designed to rapidly remove power from the faulted circuit by opening all of the conductors that could supply that fault current. Those are the ungrounded conductors. The neutral and the equipment grounding conductor are grounded or serve as safety paths, and they are not the conductors that need to be interrupted to clear the fault. If you only opened the neutral or only the equipment grounding conductor, the energized ungrounded conductors could still supply fault current and the fault would not be cleared. Opening all ungrounded conductors ensures the fault current has no supply path and the circuit can be safely de-energized.