Abstract: A device is provided for operating a circuit breaker handle. The device includes a body having a receiving area to receive and engage a portion of the circuit breaker handle. The body is fixedly secured to a shaft for movement between a first position and a second position. The body is caused to move by a forces from a first coil and a second coil. The first coil generates a first force in a first direction, and the second coil generates a second force in a second direction, wherein the second direction is opposite to the first direction. The first and second forces are transferred to the shaft for effectuating movement between the first and second positions.

Abstract: A spring-loaded cam electrical connector is used to rapidly connect circuit breaker load terminal straps with the associated electric distribution system wire conductors. Rotation of the cam in one direction traps the end of the wire conductor between the bottom of the cam support and the circuit breaker load terminal strap to make the electrical connection while rotation of the cam in the opposite direction releases the end of the wire conductor to break the electrical connection.

Abstract: A circuit interrupter employing an electronic trip unit utilizes a current transformer assembly containing both air and metal cores on a common load strap for providing sensing current to the electronic trip unit along with supplying operating power to the trip unit electronic components. A two-part plastic housing provides support for the metal core and the sensing coil while further providing thermal transfer of heat generated within the transformer secondary windings out to the load strap.

Abstract: A spring-loaded cam electrical connector is used to rapidly connect circuit breaker load terminal straps with the associated electric distribution system wire conductors. Rotation of the cam in one direction traps the end of the wire conductor between the bottom of the cam support and the circuit breaker load terminal strap to make the electrical connection while rotation of the cam in the opposite direction releases the end of the wire conductor to break the electrical connection.

Abstract: Molded case circuit breaker accessories using slightly modified circuit breaker cases are described. Several of the accessories utilize a microswitch to provide remote indication of an auxiliary function. One modification of the circuit breaker case includes upstanding posts to capture and position the microswitch while a further modification utilizes the magnetic trip unit adjustment screw and a support plate.

Abstract: A molded case circuit breaker interlock unit connects between a fuse enclosure attached to one end. Upon the occurrence of a short circuit within a protected circuit, the fuse operates to isolate the protected equipment and is conveniently replaced without disassembling the circuit breaker components. The interlock unit prevents resetting the circuit breaker operating mechanism until the fuse is replaced.

Abstract: A molded case circuit breaker handle interlock unit is arranged on the top surface of the circuit breaker to lockingly prevent intentional displacement of the circuit breaker operating handle from either the ON or OFF positions. The movable clip on the unit is attached to the circuit breaker handle to prevent tampering.

Abstract: A molded case circuit breaker handle interlock unit is arranged on the top surface of the circuit breaker to lockingly prevent intentional displacement of the circuit breaker operating handle from either the ON or OFF positions. The movable clip on the unit is attached to the circuit breaker handle to prevent tampering.

Abstract: An electric circuit breaker operating mechanism includes an insulated armature latch which prevents deleterious arc formation between the operating mechanism cradle and the armature latch surface when the circuit breaker contacts are separated under overcurrent circuit conditions. The insulated armature latch carries a tolerance take-up spring which interacts between the operating mechanism cradle and the circuit breaker trip bar assembly to insure free travel of the operating cradle during contact separation.

Abstract: The secondary latch of a molded case circuit breaker latching arrangement is formed from a latching pin assembly with a solid metal latching sphere rotatably mounted at one end thereof. The latching sphere contacts the operating mechanism latching plate to provide a low-friction latching force to the circuit breaker operating mechanism. The latching sphere contacts the latching plate and is continuously lubricated by means of a lubrication reservoir integrally-formed within the latch pin assembly.

Abstract: A combination panelboard-switchboard housing accepts plug-on connection with a plurality of modular electric switch-circuit breaker enclosures. The modular enclosure accepts circuit breakers or electric switches which can be field-installed with minor alteration to the enclosure. The modular switch enclosure further accepts a wide range of ampere ratings within a standard enclosure size. A mechanical latch arrangement on the bottom of the modular enclosure prevents the modular enclosure from being removed from the panelboard-switchboard housing. Controlled temperatures are achieved within the housing by optimized circulating air flow.

Abstract: An undervoltage release accessory is attached to the interior of a circuit breaker enclosure proximate the operating handle assembly. A reset mechanism positioned between the handle operator and the undervoltage release plunger resets the undervoltage release plunger after an undervoltage condition. A flexible reset spring on the reset mechanism compensates for mechanical tolerances between the reset mechanism and the undervoltage release plunger.

Abstract: A thermal shield is employed with a circuit breaker operating spring to protect the spring from thermal degradation during contact arcing. One embodiment includes an ablative plastic coating on the outer surface of the shield to promote arc quenching.