Arc-fault circuit interrupter:The arc generated due to poor contact of the contact or damage to the insulation of the circuit is called a “bad arc”, corresponding to a “good arc”. The arc generated by normal operation of the switch is called a “good arc”. That is to say, “bad arcs” can do bad things and cause fire hazards. If not dealt with in a timely manner, “bad arcs” can cause significant economic losses and even casualties.