Which device protects a circuit from ground faults?

• A. AFCI breakers
• B. GFCI breakers
• C. Dual-function breakers
• D. Overload protectors

Answer: (B)

Ground faults occur when current takes an unintended path to earth, which can shock someone who touches the equipment. A ground-fault protection device uses a differential sensor to compare the current in the hot conductor and the return path. If leakage to ground happens, the currents aren’t equal, and the device trips quickly to cut power. That is exactly what a ground-fault circuit interrupter does, whether built into a breaker to protect the whole circuit or placed in an outlet to protect downstream devices. They typically trip at very low leakage levels (around 4–6 milliamps) to prevent shock.

AFCI breakers, by contrast, protect against dangerous arcing that can ignite fires. Dual-function breakers combine both features, but the function that targets ground faults is the GFCI. Overload protectors guard against excessive current but don’t specifically address ground leakage.