When ___ touch together, this is a ground fault.

When ___ touch together, this is a ground fault.

• A. an ungrounded and a grounded circuit conductor
• B. an ungrounded circuit conductor and the metal conduit
• C. two ungrounded circuit conductors
• D. a or b only

Answer: (B)

Ground faults happen when current takes an unintended path to earth or a grounded part. If a live (ungrounded) conductor touches metal conduit, the conduit—being bonded to the grounding system—provides a path back to the source through the earth/grounding path. That’s a fault to ground and is exactly what ground-fault protection (like GFCIs) is designed to detect. Touching hot to neutral would create a direct short between line and neutral, not a ground fault through the grounding path. Two hot conductors touching would be a phase-to-phase short, again not a ground fault. So the situation where an ungrounded conductor contacts the metal conduit best fits a ground fault.

Ground faults happen when current takes an unintended path to earth or a grounded part. If a live (ungrounded) conductor touches metal conduit, the conduit—being bonded to the grounding system—provides a path back to the source through the earth/grounding path. That’s a fault to ground and is exactly what ground-fault protection (like GFCIs) is designed to detect.

Touching hot to neutral would create a direct short between line and neutral, not a ground fault through the grounding path. Two hot conductors touching would be a phase-to-phase short, again not a ground fault. So the situation where an ungrounded conductor contacts the metal conduit best fits a ground fault.