Abstract: A static trip, molded case circuit breaker includes an operating mechanism having powerful mechanism springs to achieve the requisite contact pressures for high current carrying capacity. A rotary handle resets the operating mechanism via a reciprocating slide and a latching mechanism, while loading the mechanism springs. Return of the handle to its original position achieves rapid closure of the circuit breaker contacts. The latching mechanism is equipped with a trip interlock operating to trip the circuit breaker in response to removal of the case cover and to thereafter disable resetting of the operating mechanism in the absence of the cover and/or electronic trip unit.