Abstract: A circuit breaker includes separable contacts, an operating mechanism structured to open and close the separable contacts, a molded enclosure comprising a first molded portion and a second molded portion, a plurality of thread cutting screws fastening the first molded portion to the second molded portion, and a plurality of machine screws. The first molded portion and the second molded portion cooperate to form a plurality of exterior walls. The exterior walls define an interior volume, which encloses the separable contacts and at least a portion of the operating mechanism. The machine screws extend within and reinforce the exterior walls and restrict expansion of the exterior walls away from the interior volume.

Abstract: A circuit breaker includes fixed and movable contacts, an operating mechanism including a movable arm carrying the movable contact, an arc chute including a plurality of spaced apart first and second arc plates, and a slot motor. A slot motor structure is disposed about the contacts and a portion of the movable arm. An insulative housing at least substantially covers and insulates the slot motor structure from the movable arm and contacts. The insulative housing includes a base and a pair of arms disposed therefrom. Each of the arms includes a first portion disposed proximate the first arc plates and a second smaller portion disposed proximate the second arc plates. A space extending from the first portion, not occupied by the second portion, is generally occupied by a portion of the second arc plates. The second portion forms a debris shield between the second arc plates and the operating mechanism.

Abstract: A rotating display device displays a value in a variable viewing orientation. The value is received from an electrical apparatus, such as a circuit breaker, having a first port. The rotating display device includes a housing having a first side and a second side, a display disposed on the first side of the housing, a rotating assembly disposed on the second side, and a second port for receiving the value from the first port of the electrical apparatus. The second port communicates with the display and is coupled to the rotating assembly in order to permit the display to rotate. The rotating assembly permits the rotating display device to rotate in the plane of the surface of the circuit breaker on which it is mounted, thereby permitting the display to be quickly and accurately viewed and interpreted regardless of the orientation of the surface to which it is coupled.

Abstract: A trip unit for a circuit breaker for an electrical circuit includes a current transformer adapted to sense a current flowing in the electrical circuit and to provide a signal representative of the current. A microprocessor includes a memory, a rotary selector switch, and a routine evaluating the sensed current with respect to a plurality of predetermined current/time conditions, such as long delay protection, override protection, short delay protection and/or ground fault protection, and responsively generating a trip signal. The rotary selector switch has a plurality of positions. Each of the positions selects a first time value, such as a short delay time for a first one of the predetermined current/time conditions, and selects a second time value, such as a ground fault time, for a different second one of the predetermined current/time conditions.

Abstract: A trip unit includes a housing, a rotary plunger mounted in the housing and a pivotal trip bar also mounted therein. The trip bar latches the plunger in an on position, releases the plunger to a tripped position and re-latches the plunger. A set of springs biases the plunger to the tripped position. A rotary trip lever is pivotally mounted in the housing. A trip solenoid includes a linear plunger, which resets the solenoid when retracted, and which engages and rotates the trip lever when extended, in order to rotate the trip bar and release the rotary plunger. The rotary plunger engages the rotary trip lever when reset and rotates the same in an opposite direction, in order to retract the linear plunger and reset the solenoid. During that reset operation, the rotary plunger also cams the trip bar, in order to re-latch the rotary plunger in the on position.

Abstract: A trip unit includes a housing, a rotary plunger, and a pivotally mounted trip bar, which latches the plunger in an on position and releases the plunger to a tripped position. A first plunger portion is biased outside the housing in a tripped position by a spring mechanism. A pivotally mounted rotary trip lever includes an elastic arm. A second plunger portion is inside the housing in a reset position and engages the elastic arm. When a trip solenoid is energized, its linear plunger rotates the rotary trip lever, in order to engage and rotate the trip bar and release the rotary plunger. The rotary trip lever rotates in an opposite direction in response to the rotary plunger reset position and engages the trip solenoid linear plunger, in order to reset the same. The elastic arm flexes after the linear plunger is reset and accommodates overtravel of the rotary plunger.

Abstract: A circuit breaker trip unit includes a housing and a rotary plunger pivotally mounted within the housing. The rotary plunger has an on position and a tripped position. A portion of the rotary plunger is pivoted outside of the housing in the tripped position. A trip bar is pivotally mounted within the housing and includes a first tab latching the rotary plunger in the first position and releasing the rotary plunger from the first position. The trip bar also includes a second tab. A trip actuator includes a solenoid and a rotary trip lever engaging the second tab of the trip bar, in order to pivot the trip bar and release the rotary plunger from the on position. A spring biases the trip bar, in order that the first tab latches the rotary plunger in the on position. A pair of springs biases the rotary plunger to the tripped position.

Abstract: A method attaches a center conductor to one or both of a load end conductor and a line end conductor. The center conductor has two cylindrical projections. The load end conductor and the line end conductor both have a non-circular opening, such as a square opening. One of the cylindrical projections of the center conductor is passed through the non-circular opening of the load end conductor. The cylindrical projection of the center conductor is deformed, in order to attach the center conductor and the load end conductor together. The other of the cylindrical projections of the center conductor is passed through the non-circular opening of the line end conductor. The load and line end conductors are aligned and the other cylindrical projection of the center conductor is deformed, in order to attach the center conductor and the line end conductor together.