Patent ID: 7423858

Claim:
Apparatus comprising: a circuit breaker including a switching mechanism in a box-shape case having opposite ends; and a current sensor unit including a current sensor self-contained in an additional box-shape case, wherein the case of the current sensor unit is connected with one end of the case of the circuit breaker, wherein a flexible current carrying conductor of the circuit breaker is routed from the case of the circuit breaker into the additional case so as to pass through the current sensor unit, wherein the current sensor unit has an integral annular magnetic core located entirely in the additional case and mounted to a circuit board in the additional case, wherein the flexible conductor is wound about a portion of the magnetic core, wherein the circuit breaker has an overcurrent-responsive tripping device connected in a main current carrying circuit extending between terminals external to a side of the circuit breaker case, and wherein the current sensor unit includes electronic circuitry with an output terminal that is devoid of connection to the tripping device and that provides an output signal related to the current carried by the flexible current carrying conductor.