The "AFCI" protects your home against fires caused by unwanted arcing. The AFCI monitors the flow through it, and recognizes the difference between normal and unwanted arcing conditions. If an unwanted arc is detected, the AFCI trips the circuit.

AFCIs have two purposes, one is to detect unwanted arcs and trip the circuit, and the other is to also trip when a short circuit or an overload occurs.

In 2002 it became required for AFCIs to be installed into bedroom receptacles. It should be considered for addition protection in other circuits, especially in older homes with aging and deteriorating wiring.