Patent ID: 7149066

Claim:
Apparatus for protecting an electric power distribution system comprising a first line conductor, a second line conductor, and a common neutral conductor, the apparatus comprising: a first circuit breaker pole comprising: first separable contacts connected in the first line conductor; a first arc fault detector generating a first fault signal in response to arc fault currents in the first line conductor; and a first trip unit comprising a first trip coil and a first unidirectional switch connected in series at a first node, with the first trip coil connected to the neutral conductor and the first unidirectional switch connected to the first line conductor, the first unidirectional switch being turned on by the first fault signal to energize the first trip coil and open the first separable contacts; a second circuit breaker pole comprising: second separable contacts connected in the second line conductor; a second arc fault detector generating a second fault signal in response to arc fault currents in the second line conductor; and a second trip unit comprising a second trip coil and a second unidirectional switch connected in series at a second node, with the second trip coil connected to the neutral conductor and the second unidirectional switch connected to the second line conductor, the second unidirectional switch being turned on the second fault signal to energize the second trip coil and open the second separable contacts; and a jumper connected at a first end to the first node and a second end to the second node to directly connect the first and second nodes without electrical isolation and so that the turn on of either one or both of the first unidirectional switch and the second unidirectional switch energizes both the first trip coil and the second trip coil to open both the first and second separable contacts.