The well-known crack of a rifle, whose ball came skipping along the placid surface of the strait, and a shrill yell from the island, interrupted his speech, and announced that their passage was discovered.
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).
Breakers designed to protect against parallel arcs are called Arc-Fault Circuit Breakers, have a suffix AFI, and have a green test button (early versions had a blue button). An example catalog number is QO120AFI. CAFI - Combination Arc-Fault Circuit Breakers (protection against over loads, short circuit, parallel arcing, and series arcing) Breakers with CAFI suffix provide standard thermal/magnetic protection, PLUS protection against heat damage caused by parallel AND SERIES arcing in the circuit.