What does an arc fault circuit interrupter (AFCI) do?

An arc fault circuit interrupter (AFCI) is specifically designed to detect arcing faults that can occur in electrical circuits. These faults may arise due to damaged wiring, loose connections, or aged electrical devices, and they can lead to fires if not addressed. The AFCI's primary function is to monitor the electrical current and sense the distinct patterns of arcing. Upon detecting such an arc, the AFCI quickly interrupts the electrical circuit to mitigate the risk of fire, thereby enhancing safety in residential and commercial environments.

This protective feature distinguishes AFCIs from other devices such as circuit breakers, which primarily prevent overloads by interrupting current flow when it exceeds a certain limit, but do not specifically recognize arcing faults. Additionally, converting AC to DC power is a function of rectifiers or power supplies, while monitoring battery performance is relevant to battery management systems. Hence, the primary role of an AFCI focuses on the detection and protection against arcing faults, positioning it as a crucial safety device in modern electrical systems.