what is a afci device
An arc fault circuit interrupter (AFCI) is a circuit breaker that breaks the circuit when it detects an electric arc in the circuit it protects to prevent electrical fires. An AFCI selectively distinguishes between a harmless arc (incidental to normal operation of switches, plugs, and brushed motors), and a potentially dangerous arc (that can occur, for example, in a lamp cord which has a broken conductor).