Patent ID: 7035066

Claim:
An arc-fault detecting circuit-breaker system operable with a protected electrical circuit, the arc-fault detecting circuit-breaker system comprising: a normally closed line circuit breaker connected in series by an electrical line with the protected electrical circuit whose current flow is to be interrupted upon the occurrence of an arc fault; a detector of a rate of change with time of the current flow in at least one of the protected electrical circuit and the electrical line; an activating element alternating current voltage source having an activating element alternating current output at an activating element alternating current output frequency; and a circuit-breaker activating element operable responsive to the detector, wherein the circuit-breaker activating element is electrically connected between the electrical line and the activating element alternating current output, and wherein the circuit-breaker activating element is a normally open switch that closes to establish a connection between the electrical line and the alternating current output in the event that the detector detects the rate of change with time of the current flow in excess of a permitted maximum rate-of-change value.