Which device is designed to rapidly interrupt current when a ground fault is detected?

Which device is designed to rapidly interrupt current when a ground fault is detected?

• A. Ground fault circuit interrupter (GFCI)
• B. Overcurrent protective device
• C. Surge protector
• D. Voltage regulator

Answer: (A)

Ground-fault protection works by watching the current in the hot and neutral conductors and looking for any imbalance. If some current leaks to ground—such as through a person or moisture—the currents no longer match. The GFCI detects this small leakage, typically around 4–6 milliamps, and trips quickly to cut power. This rapid interruption minimizes the risk of electric shock, especially in wet or damp locations where contact with ground or conductive surfaces is more likely. Other devices don’t serve this purpose. An overcurrent protective device trips only when current exceeds its rating, protecting conductors from overheating but not specifically responding to ground faults. A surge protector focuses on protecting equipment from voltage spikes and doesn’t monitor leakage between hot and neutral. A voltage regulator maintains a steady output voltage and does not interrupt current in response to ground faults. So, the device designed to rapidly interrupt current when a ground fault is detected is a Ground-fault circuit interrupter (GFCI).

Ground-fault protection works by watching the current in the hot and neutral conductors and looking for any imbalance. If some current leaks to ground—such as through a person or moisture—the currents no longer match. The GFCI detects this small leakage, typically around 4–6 milliamps, and trips quickly to cut power. This rapid interruption minimizes the risk of electric shock, especially in wet or damp locations where contact with ground or conductive surfaces is more likely.

Other devices don’t serve this purpose. An overcurrent protective device trips only when current exceeds its rating, protecting conductors from overheating but not specifically responding to ground faults. A surge protector focuses on protecting equipment from voltage spikes and doesn’t monitor leakage between hot and neutral. A voltage regulator maintains a steady output voltage and does not interrupt current in response to ground faults.

So, the device designed to rapidly interrupt current when a ground fault is detected is a Ground-fault circuit interrupter (GFCI).