Abstract: A circuit interrupter including a housing, separable main contacts within the housing, and an operating mechanism within the housing and interconnected with the separable main contacts. A trip mechanism is disposed within the housing that includes a trip bar assembly rotatable about an axis and that, when rotated, generates a tripping operation causing the operating mechanism to open the contacts. The trip bar assembly includes a trip member translatable along the axis. The trip mechanism includes a tripping actuator movable along a predetermined path of travel as a function of electrical current. The tripping actuator contacts a contact area of the trip member at a predetermined location along the predetermined path of travel of the tripping actuator and causes the trip bar assembly to rotate and generate the tripping operation upon a predetermined current threshold.

Abstract: An adjustable magnetic trip device for a molded case circuit breaker is provided where the trip device includes a plunger and a stationary core as well as a plunger support structure with a movable plunger carriage. The position of the plunger assembly and carriage relative to the stationary core is determined by a cam assembly having a body with a plurality of sections, each section having a different radius. The plunger carriage is responsive to rotation of said cam assembly and may be adjusted by rotating the cam. The over-current condition for the trip device is a function of the distance between the plunger assembly and the stationary core. Accordingly, the over-current condition may be changed by rotating the cam. As each section of the cam has a constant radius, the over-current condition remains the same no matter where the carriage contacts a certain section of the cam.

Abstract: A plunger assembly support structure for a molded case circuit breaker magnetic trip mechanism for aligning a trip mechanism plunger assembly. The plunger assembly support structure includes a base member assembly having a plurality of guide members, and a plunger carriage assembly slidably disposed adjacent to said base member assembly.