Which component is essential for a GFCI to function properly?

A Ground Fault Circuit Interrupter (GFCI) is designed to protect individuals from electric shock by monitoring the current flowing through a circuit. For a GFCI to function properly, it requires both the hot (live) and neutral conductors to operate accurately. The GFCI continuously compares the amount of current flowing in the hot conductor to the amount returning through the neutral conductor. If there is a discrepancy—indicating a ground fault where current is leaking through an unintended path, such as through a person—the GFCI will trip and cut off power to prevent harm.

While the ground conductor is important for safety and provides a path for fault currents, it is not critical for the basic operational functionality of the GFCI itself. Load sharing is not a relevant factor in the performance of a GFCI. Thus, the neutral conductor plays a crucial role in allowing the GFCI to detect imbalances, making it essential for the device’s proper functioning.