Abstract: A circuit breaker has a set of remotely controllable secondary contacts electrically connected in series with the main contacts which provide overcurrent or fault current protection. An operating mechanism opens and closes the set of main contacts. The secondary contacts are opened and closed by a latching solenoid. The latching solenoid includes a plunger latchable to a first position, which opens the set of secondary contacts, and to a second position which closes the set of secondary contacts. The latching solenoid also includes an open/close coil which when energized with a first polarity signal operates the plunger to the first position and which when energized with an opposite second polarity signal operates the plunger to the second position. A circuit is structured for cooperation with a remote control circuit for energizing the coil with the first polarity signal or, alternatively, the second polarity signal.

Abstract: A miniature circuit breaker incorporating ground fault protection and arc fault protection includes main separable contacts. An operating mechanism actuated by a trip mechanism opens the main separable contacts in response to predetermined current conditions. Auxiliary separable contacts are disposed in series with the main separable contacts. A solenoid having a movable plunger opens and closes the auxiliary separable contacts in response to a remote external signal. A ground fault trip circuit detects a ground fault, and an arc fault trip circuit detects an arc fault. An actuator mechanism, energizable by the ground fault trip circuit and the arc fault trip circuit, actuates the plunger to open the auxiliary separable contacts.

Abstract: Electrical switches and circuit breakers in which the contacts and operating mechanism are enclosed within an insulating housing by an insulating cover and which have an elongated operating handle extending through an elongated slot in the cover have an enlarged terminal portion of the operating handle which is wider than the slot to prevent removal of the cover except in positions of the handle at which the electrical contacts are open and the slot is wider than the terminal portion of the handle. Preferably, this is only the OFF position of the switch or breaker, however, in circuit breakers with a notch at the trip position to expose indicia indicating the breaker operating condition, a transverse pin through the operating handle permitting removal of the cover only with the operating handle in the trip position, provides an economical backfit.

Abstract: A circuit breaker having a trip delay mechanism characterized by a variable magnetic air gap that is adjustable to permit time delay at low level overcurrents to avoid nuisance tripping during motor starting.

Abstract: A molded case circuit breaker includes an operating mechanism position indicator having a plurality of electrically insulating cards or strips disposed beneath an opening in the breaker cover about a manually engageable handle of the circuit breaker for movement in response to movements of the handle along the cover opening. A first one of the cards includes a pair of spaced apart, laterally aligned red markings for providing an externally visually discernible indication that the operating mechanism of the circuit breaker is in its CLOSED position. The first card also includes a pair of spaced apart, laterally aligned white markings for providing an externally visually discernible indication that the operating mechanism of the circuit breaker is in its TRIPPED position. The second card is positioned beneath the first card and is of a substantially greater length than the first card.

Abstract: A molded case circuit breaker includes a new and improved calibration adjusting means for a bimetal in a trip mechanism. The trip mechanism also includes a bimetal having a portion movable in response to predetermined overload conditions, an intermediate control lever for adjusting the spatial disposition of the movable portion of the bimetal with respect to a trip bar of the trip mechanism and a rotatable adjustment means for adjusting the spatial disposition of the intermediate control lever in the circuit breaker. By rotating the adjustment means, the distance between the movable portion of the bimetal and the trip bar can be precisely adjusted via the intermediate control lever. The intermediate control lever is coupled to a relatively stationary portion of the bimetal thereby enabling such adjustment without applying undue stress to the movable portion of the bimetal.

Abstract: An arc chute assembly for a circuit breaker or similar device comprising a series of metallic arc chute plates that are locked in stacked spaced-apart relationship between a pair of insulative side panels by elongated key members of non-conductive material that are wedged between the flat surfaces of the side panels and notched portions of pairs of T-shaped tabs which extend from each side edge of the respective plates. The tabs interlockingly engage a series of laterally-extending slot openings in the side panels in such a manner that the key members are in press-fitted engagement with only one of the tabs in each pair of tabs.

Abstract: A telescoping high current disconnect switch for isolated phase bus includes a pair of axially spaced cylindrical fixed conductors insulatingly mounted within a cylindrical aluminum housing. An aluminum telescope section is coaxial with the fixed conductors and is insulatingly mounted upon a plurality of rollway pillow blocks each containing ball bearings. The pillow blocks are supported by guide rails of austenitic non-ferromagnetic stainless steel which are attached to the interior surface of the housing. The telescope section is axially movable along the guide rails to bridge the fixed conductors, such movement causing the ball bearings to cold-form grooves in the rails, whereby portions of the rails are work-hardened.

Abstract: A circuit breaker with an anti-bounce mechanism characterized by separable contact means operable between open and closed positions and including a cross bar, an operating mechanism releasable to effect movement of the contacts and comprising a link connected to the cross bar, means for preventing bouncing of the cross bar when the contacts are open and comprising a stop member engageable with the length.

Abstract: An isolated phase bus disconnect switch has a cylindrical aluminum center conductor coaxially disposed within a cylindrical aluminum housing. The center conductor is composed of two fixed axially spaced sections and a coaxial telescoping sleeve assembly which moves axially to make and break electrical contact between the fixed sections. One end of each fixed section and both ends of the sleeve assembly have copper contact rings fixedly attached thereto. Adjoining surfaces of the copper-aluminum interfaces are silver plated, and each of the adjoining aluminum members is axially slotted to permit flexing to allow for differential thermal expansion, while at the same time preventing relative motion between the plated surfaces.

Abstract: A circuit breaker having stationary and movable contacts operable between open and closed positions with the movable contact being biased in an open position. The movable contact is mounted to a contact holder which engages one link in a toggle means. The first link is connected to a second link which has a drive pin secured thereto, and the second link is pivotally connected to a toggle lever. A cam is secured to a rotatable drive shaft, and the cam engages a cam roller which is secured to a follower plate. The follower plate has a drive pawl attached thereto, with the drive pawl being disposed adjacent the drive pin. Spring means are pivotally connected to the follower plate and are capable of being in spring charged and discharged positions. The spring is charged by rotation of the drive shaft and cam causing the cam roller to move outwardly. The outward movement of the cam roller causes rotation of the follower plate, resulting in charging of the spring means.

Abstract: A circuit breaker having stationary and movable contacts operable between open and closed positions. Movement effecting means causes relative movement of the movable contact between open and closed positions, and a closing spring assembly imparts movement to the movement effecting means to move the movable contact to the closed position. The closing spring assembly includes first and second members and a helical closing spring, with the first and second members extending into the central opening of the spring. Shock absorbing means is disposed within the spring opening to absorb energy released when the assembly is discharged.

Abstract: Each section of a three-phase metal enclosed switchgear unit is provided with main through horizontal bus and vertical section bus. The front of each switchgear section is divided into vertically disposed enclosures for housing circuit breakers or circuit interrupting devices. The circuit breakers are mounted close to the vertical section bus with the front of the circuit breaker and the circuit breaker operating handle recessed from the front of the switchgear section. Pan or well-shaped front covers, having a bottom surface flushed with the circuit breaker fit over the front of the vertically disposed enclosures and are mounted to the front of the switchgear section. Different depth wells or pans are used for the front cover, with the depth being determined by the circuit breaker physical size, which is dependent on the breaker rating. The surface of the well flush with the circuit breaker device has a cutout through which the circuit breaker operating handle projects.