Which condition would trigger a GFCI to shut off?

Which condition would trigger a GFCI to shut off?

• A. Imbalance Between Hot and Neutral Currents
• B. Overvoltage
• C. High Temperature
• D. Short Circuit

Answer: (A)

GFCI protection works by watching the current going out on the hot conductor and coming back on the neutral. In a normal circuit, those currents are equal. If some current leaks to the ground path—through a person or other grounding path—the amount returning on the neutral is less than what left on the hot. That imbalance is exactly what the GFCI is designed to detect, and it trips to cut power, reducing the risk of shock. Overvoltage, high temperature, and short circuits don’t create this kind of current imbalance by design. Overvoltage is handled by other protective devices that respond to excessive voltage. High temperature triggers thermal protection in equipment. A simple short between hot and neutral keeps the current balanced (both conductors carry the fault current back and forth), so it would not trigger the GFCI for grounding, though a separate protective device may trip due to the high current.

GFCI protection works by watching the current going out on the hot conductor and coming back on the neutral. In a normal circuit, those currents are equal. If some current leaks to the ground path—through a person or other grounding path—the amount returning on the neutral is less than what left on the hot. That imbalance is exactly what the GFCI is designed to detect, and it trips to cut power, reducing the risk of shock.

Overvoltage, high temperature, and short circuits don’t create this kind of current imbalance by design. Overvoltage is handled by other protective devices that respond to excessive voltage. High temperature triggers thermal protection in equipment. A simple short between hot and neutral keeps the current balanced (both conductors carry the fault current back and forth), so it would not trigger the GFCI for grounding, though a separate protective device may trip due to the high current.