Abstract: A molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. The circuit breaker has external terminals which are connectable with an external load and an external power supply. A collar is used to interconnect the circuit breaker terminals with the load and power supply. The terminal collar in this case is non-symmetrical. The non-symmetrical collar provides two functions: the first function is that the path of electrical continently between adjacent collars is enlarged for higher voltage applications because of the non-symmetrical nature of each collar; secondly, the circuit breaker case has a seat therein which has the same cross-section as the non-symmetrical collar, so that the collar can only be inserted therein in one cross-sectional orientation.

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, 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: An operating mechanism for an enclosure-mounted circuit breaker includes a slider for engaging the circuit breaker handle; a shaft-driven pivot for moving the slider between the handle on, off and reset positions; a holder for holding the slider in its reset position; a base plate for supporting the pivot and the slider; and a door-mounted rotary handle for rotating the shaft and operating the pivot. The rotary handle may engage the shaft in the on and off positions, and may be detached from the shaft in the reset position. The pivot may include a first pivot arm having a first cam surface for holding the slider in its reset position. A second cam surface on a second pivot arm may engage a first slider surface from off to on; a second slider surface from on to off, from off toward reset, and to resist reset to off; and an oblique slider surface when adjacent reset. The second cam surface may disengage the oblique surface at reset.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being moved from the on position after the main contacts have been welded together. By preventing the operating handle from being moved from the on position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being placed in the off position after the main contacts have been welded together. By preventing the operating handle from being placed in an off position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being placed in the off position after the main contacts have been welded together. By preventing the operating handle from being placed in an off position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.