Abstract: A circuit breaker includes separable contacts, an operating mechanism structured to open and close the contacts, and a trip unit cooperating with the operating mechanism to trip open the contacts. The trip unit includes a sensor structured to sense current flowing through the contacts, a processor structured to output a trip signal responsive to the sensed current, and a trip actuator. The trip actuator includes a housing including a recess, a coil within the recess, the coil having an opening therethrough, a magnet within the recess, a thermoplastic bushing including a conduit therethrough, the thermoplastic bushing being coupled to the housing, and an armature disposable within the opening of the coil and slidably disposed within the conduit of the thermoplastic bushing. The magnet attracts the armature toward the housing. A spring biases the armature away from the housing, in order to cause the operating mechanism to trip open the contacts.

Abstract: A circuit breaker includes separable contacts, an operating mechanism structured to open and close the contacts, and a trip unit cooperating with the operating mechanism to trip open the contacts. The trip unit includes a sensor structured to sense current flowing through the contacts, a processor structured to output a trip signal responsive to the sensed current, and a trip actuator. The trip actuator includes a housing including a recess, a coil within the recess, the coil having an opening therethrough, a magnet within the recess, a thermoplastic bushing including a conduit therethrough, the thermoplastic bushing being coupled to the housing, and an armature disposable within the opening of the coil and slidably disposed within the conduit of the thermoplastic bushing. The magnet attracts the armature toward the housing. A spring biases the armature away from the housing, in order to cause the operating mechanism to trip open the contacts.

Abstract: A circuit breaker including a housing, separable contacts, a cradle rotatably mounted within the housing, an alarm switch mounted within the housing, and an interface lever disposed between the cradle and the alarm switch. The cradle is adapted to rotate about a first axis in a first direction when the circuit breaker moves to a tripped position in which the separable contacts are separated from one another. The alarm switch includes an actuation lever movable in an actuation direction, wherein movement of the actuation lever in the actuation direction causes the alarm switch to activate an alarm device electrically connected thereto. When the cradle rotates in the first direction, the cradle exerts a first force against the interface lever that causes the interface lever to exert a second force against the actuation lever that causes the actuation lever to move in the actuation direction.

Abstract: A securing member for use in a switch assembly of a circuit breaker includes a support post and a fastener. The securing member assists in mounting an alarm switch onto a bracket of the switch assembly and further resists movement of the actuation levers of a pair of auxiliary switches from moving beyond a first given position and from potentially becoming caught in an operating mechanism that pivots a crossbar. The dual functionality of the securing member is cost effective and occupies only a minimal amount of additional space within the crowded confines of the circuit breaker.

Abstract: A circuit breaker mounting assembly comprises an enclosure for holding at least one circuit breaker, with the circuit breaker being mounted within said enclosure; a terminal block mounted within the enclosure at a location remote from the circuit breaker, the terminal block including a plurality of input connections and a plurality of output connections; a plurality of control wires extending from the circuit breaker to the terminal block; and a mounting bracket for positioning the terminal block in a first position within the enclosure and for permitting the terminal block to be moved to a second location outside of the enclosure.

Abstract: The secondary cover of a molded case power switch housing is removably secured in place to enclose cavities in the insulative resin of a primary cover by an attachment assembly which includes metal attachment members or inserts seated in recesses in the primary cover. These inserts have tapped apertures aligned with mounting holes in the secondary cover through which screw fasteners are inserted and threaded into the tapped apertures. Such metal to metal connections can be repeatedly coupled and decoupled without significant wear as the secondary cover is removed and reinstalled to gain access to auxiliary devices mounted in the cavities in the primary cover. The inserts have second mounting apertures through which self tapping screws extend into the primary cover or through mounting holes in the primary cover and into the resin of the base to mount the inserts on the primary cover and to secure the primary cover to the base.

Abstract: A circuit breaker having a trip unit includes a lock out assembly positioned adjacent the trip unit for controlling access thereto. The lock out assembly includes a base member, a cover member and a slide member received therebetween. The slide member is moveable between various positions for controlling access to settings for the various operating parameters of the circuit breaker as provided by the trip unit.

Abstract: A molded case circuit breaker has modular crossbar members which connect the contact arm carriers of a desired number of poles for opening and closing the separable contacts of all of the poles simultaneously by a single spring powered operating mechanism. The modular crossbar members comprise shaft sections which engage openings in the contact arm carriers of adjacent poles. Bearings support the shaft sections and mount the contact arm carriers for rotation about a common pivot axis. In a preferred embodiment of the invention, the modular crossbar member is a single continuous metal shaft overmolded with an electrically insulative resin which also forms the bearing. Alternatively, separate metal shaft sections seat in sockets on either side of the molded bearing. In both instances, the shaft sections are keyed to the openings in the contact arm carriers for transmission of torque. In the exemplary crossbars, the shaft sections are hexagonal in cross-section.

Abstract: A molded case circuit breaker has a moving conductor assembly which includes a modular carrier assembly incorporating a plurality of spring biased contact cam members each of which engages contact pressure lobes on a pair of contact arm laminations to provide contact pressure. In response to the magnetic repulsion forces generated by a short circuit, the springs compress allowing the cam members to pivot and side step the contact pressure lobes so that the contact arm blows-open with little resistance. The cam members and springs are preassembled in a transverse channel in the carrier body and laterally retained in place by side plates for easier pivotal attachment of the contact arm laminations to the lobes on the side plates. The side plate lobes raise the contact arm relative to the mass of the carrier to reduce eddy current heating and provide a positive off indication for welded contacts by restricting movement of lower toggle links of the operating mechanism which are coplanar with the side plates.