Residual ground-fault protection monitors ground fault currents in which conductor?

• A. Grounding Strap
• B. Neutral Conductor
• C. Phase Conductor
• D. Equipment Grounding Conductor

Answer: (A)

Ground-fault protection is designed to detect leakage of current to earth by watching the path that carries fault current back to the source—the equipment grounding conductor. If a fault causes current to flow through the grounding path, the currents in the live conductors and the grounding conductor no longer balance, and the protective device trips. The grounding strap is simply a bonding connection used to tie metal parts to earth; it’s not the designated monitoring path for fault current. So the conductor being monitored for a ground fault is the equipment grounding conductor.