What is the main function of an AFCI arc fault breaker?

The main function of an AFCI (Arc Fault Circuit Interrupter) breaker is to sense arcing in the circuit. AFCI breakers are designed to detect certain arcing faults that can occur in electrical circuits, which could potentially lead to electrical fires. These devices monitor the electrical signatures in the circuit and can distinguish between normal operating conditions and arcing conditions caused by damaged wires, loose connections, or faulty devices. When an arc is detected, the AFCI immediately disconnects the power to reduce the risk of fire.

This function is crucial in residential wiring, particularly in areas like bedrooms where the risk of fire due to electrical faults can be significant. By focusing on the detection of arc faults, AFCIs provide an additional layer of protection beyond what traditional circuit breakers offer. The other options, such as preventing overloads, controlling surge currents, or regulating voltage spikes, refer to functions of other types of breakers or equipment, but they do not encapsulate the primary role of an AFCI breaker.