Which device type is used to interrupt excessive current in a circuit?

Which device type is used to interrupt excessive current in a circuit?

• A. Fuses or circuit breakers
• B. GFCIs
• C. Surge protectors
• D. Bonding conductors

Answer: (A)

Overcurrent protection is about disconnecting a circuit when current exceeds what the conductors and equipment can safely carry. The device that does this is a protective interrupt that opens the circuit when overload or a fault is detected. Fuses and circuit breakers are built for this purpose: a fuse contains a metal link that melts when excessive current flows, permanently opening the circuit; a circuit breaker uses a thermal or magnetic mechanism to trip and interrupt the current automatically when the load is too high or a short occurs. This is what prevents overheating and potential fires. GFCIs protect people by sensing ground-fault currents and tripping if there’s an imbalance, not by stopping overcurrent in normal operation. Surge protectors limit voltage spikes to protect equipment, rather than interrupt sustained overcurrent. Bonding conductors provide a safe, low-impedance path to equalize potential, reducing shock risk, but they do not interrupt current flow.

Overcurrent protection is about disconnecting a circuit when current exceeds what the conductors and equipment can safely carry. The device that does this is a protective interrupt that opens the circuit when overload or a fault is detected. Fuses and circuit breakers are built for this purpose: a fuse contains a metal link that melts when excessive current flows, permanently opening the circuit; a circuit breaker uses a thermal or magnetic mechanism to trip and interrupt the current automatically when the load is too high or a short occurs. This is what prevents overheating and potential fires.

GFCIs protect people by sensing ground-fault currents and tripping if there’s an imbalance, not by stopping overcurrent in normal operation. Surge protectors limit voltage spikes to protect equipment, rather than interrupt sustained overcurrent. Bonding conductors provide a safe, low-impedance path to equalize potential, reducing shock risk, but they do not interrupt current flow.