Multiple capacity circuit breaker

Abstract

A circuit breaker including an overload trip mechanism having a current sensitive element forming a first load current conductive path. The trip mechanism is activated in response to a predetermined level of current through the trip current path. A multiple pole switch unit selectively connects a plurality of shunt load current conductive paths of various resistance values in parallel with the trip current path. The switch is operated by a cam member externally insertable into the circuit breaker in any one of a plurality of camming positions which set the switch unit to provide selected shunt current paths. Removing of the cam from the circuit breaker activates an interlock for automatically tripping the breaker. An alternative embodiment is presented wherein a contact switch unit connects, through a selectable resistance element, a shunt load current conductive path in parallel with the trip current path. The contact switch is activated by a resistance element externally insertable into the circuit breaker. Selection of the resistance element modifies the resistance of the current path in shunt with the current sensitive element to change the current rating of the breaker.

Dependencies are inferred from the claim text.