Abstract: A circuit breaker includes a housing, an operating mechanism and separable main contacts, and a rotatable crossbar which rotates to open and close the contacts. The crossbar interacts by way of a protrusion thereon with a rotatable, positive off-link. A handle mechanism is disposed in the housing and has a handle protruding from the housing which is normally movable from a closed to open disposition. However, if the operating mechanism has reacted in such a way as to open the separable main contacts but, in fact, they have not opened because, for example, they are welded shut, the protrusion on the crossbar will interact with the positive off-link and prevent the handle mechanism from moving to the opened position thus warning personnel that the contacts have not opened.

Abstract: A circuit breaker includes a housing having an opening; separable contacts disposed within the housing and moveable between a closed position and an open position; an operating mechanism having a trip position where the separable contacts are tripped open for moving the separable contacts between the closed and open positions; a trip mechanism cooperating with the operating mechanism for tripping the operating mechanism to the trip position; an electromagnetic mechanism cooperating with the trip mechanism for sensing a current flowing between the separable contacts and engaging the trip mechanism with an armature in response to a predetermined current flowing between the separable contacts; and a manual push-to-trip mechanism operatively associated with the opening of the housing and cooperating with the electromagnetic mechanism for engaging the armature thereof, in order to engage the trip mechanism, trip the operating mechanism to the trip position, and trip open the separable contacts.