ARC-FAULT DETECTING CIRCUIT BREAKER SYSTEM

摘要

An arc-fault detecting circuit-breaker system (20) is operable with a protected electrical circuit (22) that operates with direct current or alternating current. A normally closed line circuit breaker (26) has an electrical input and an electrical output, and an electrical line (24) connects the electrical output to the protected-element input. The system includes a detector (24) of the rate of change with time of a current flow i n the electrical line (24). An activating element alternating current voltage source (36) has an alternating current output. A circuit-breaker activating element (32) is operable responsive to the detector (24). The circuit-breake r activating element (32) is electrically connected between the electrical lin e (24) and the alternating current output. The circuit breaker activating element (32) is a normally open switch that closes to establish a connection between the electrical line (24) and the alternating current output in the event that the detector (24) detects a rate of change of current with time i n excess of a permitted maximum rate-of-change value.