A circuit breaker includes a housing including a primary cover and a secondary cover having a tab; separable contacts; and an operating mechanism adapted to open and close the separable contacts. The operating mechanism includes a cradle pivotally mounted within the housing, the cradle including a latch, and a latch mechanism within the housing. The latch mechanism is adapted to capture the latch of the cradle when the separable contacts are closed. The operating mechanism also includes a rotary interlock pivotally mounted within the housing and cooperating with the latch mechanism and the tab of the secondary cover to release the latch of the cradle and to trip open the separable contacts when the secondary cover is removed from the primary cover.