What is the purpose of a ground fault circuit interrupter (GFCI) in limited-energy circuits?

• A. To rapidly disconnect power if a ground fault is detected, improving safety.
• B. To regulate wire gauge.
• C. To increase current capacity.
• D. To convert AC to DC.

Answer: (C)

The main concept is that a GFCI protects people by quickly interrupting power when a ground fault is detected. In limited-energy circuits, even small leakage can pose a shock risk, so the GFCI prevents harm by tripping fast, typically within about 25 milliseconds, whenever there’s an imbalance between the hot and neutral currents. It monitors the currents and if some current escapes the circuit path (for example, through a person), it opens the circuit to stop the shock hazard.

It doesn’t regulate wire gauge, increase current capacity, or convert AC to DC, so those functions aren’t related to what a GFCI does.