Abstract: A circuit interrupter includes an automatic circuit breaker in a draw-out unit removably mounted within an enclosure. A levering mechanism is provided to lever out the draw-out unit on rails to permit complete disengagement of the circuit breaker from load and line terminals mounted within the enclosure without requiring unbolting operations. The circuit breaker includes an interrupter module, an operating module, and a control module, each of which includes a sub-frame supporting all module components. Each module is removably mounted in a main support structure and can be separately removed therefrom without removing the other two modules. Interlocks prevent removal of any module until the draw-out unit is levered out to the completely disengaged position.