Abstract: An oil-immersed circuit breaker is provided having a mechanical/magnetic trip indicator. In a preferred embodiment, the trip indicator comprises a mechanical drive train (coupled to a conventional trip-sensing mechanism), a push piece, and an indicator piece. The drive train and the push piece are located inside the enclosure immersed in oil. The indicator piece is located outside the enclosure. The push piece is magnetically coupled to the indicator piece. Magnetic coupling eliminates problems encountered with prior art trip indicators associated with oil-seal leakage, electrical component failure, and power source failure.

Abstract: An oil-immersed circuit breaker is provided having a mechanical/magnetic trip indicator. In a preferred embodiment, the trip indicator comprises a mechanical drive train (coupled to a conventional trip-sensing mechanism), a push piece, and an indicator piece. The drive train and the push piece are located inside the enclosure immersed in oil. The indicator piece is located outside the enclosure. The push piece is magnetically coupled to the indicator piece. Magnetic coupling eliminates problems encountered with prior art trip indicators associated with oil-seal leakage, electrical component failure, and power source failure.

Abstract: A preferred embodiment of an interrupter assembly for a circuit breaker includes a first contact, a conductor, and a second contact mounted on the conductor. The second contact and the conductor are movable in relation to the first contact between a first position wherein the first and the second contacts are in electrical contact, and a second position. The interrupter assembly also includes a body having a first and a second half each having a plurality of recesses formed therein. The recesses form chambers within the body for holding insulating fluid when the first and the second halves are mated. The body receives the second contact and the conductor so that the conductor and the second contact are drawn through the chambers as the second contact moves from the first to the second position.

Abstract: A de-energized tap changer is disclosed that includes a contact rail assembly, a gear assembly, a handle assembly and a transmission system that compensates for angular misalignment of the gear assembly and handle assembly. The transmission system includes two elongated members with attached blocks that fit inside a hollow tube and when the handle of the de-energized tap changer is rotated, torque is transmitted through the transmission system to the gear assembly which drives the movable contacts.

Abstract: An oil-immersed switch characterized by movable contacts mounted on a piston for movement in a cylinder for forcing oil or dielectric fluid through stationary contacts for extinguishing any arc during opening and closing of the contacts, and whereby any arcing generated during closure of the contacts generates gas pressure which acts upon a piston for aiding enclosure of the contacts.

Abstract: Protected liquid-filled electrical inductive apparatus having a dry well fuse assembly which includes a dry well fuse holder sealingly disposed through an opening in the associated metallic casing, separate from the electrical bushings, and a removable fuse portion. The dry well fuse holder includes first and second spaced terminals each having portions immersed in the liquid dielectric and portions accessible within the dry well for cooperative engagement with contacts on the removable fuse portion. The first terminal is closer to the metallic casing than the second terminal. Ionization of the air within the dry well fuse holder adjacent to the first terminal is prevented by a tubular shield member mounted on the outside of the dry well fuse holder. One of the axial end portions of the tubular shield member makes electrical contact with the immersed portion of the first terminal.

Abstract: Protected liquid-filled electrical inductive apparatus having a dry well fuse assembly which includes a dry well fuse holder sealingly disposed through an opening in the associated metallic casing, separate from the electrical bushings, and a removable fuse portion. Ionization of the air within the fuse holder is prevented by a resilient plug mounted on the removable fuse portion which, when the fuse portion is assembled within the dry well fuse holder, is immediately adjacent to the electrical terminal which is closest to the grounded casing. The resilient plug member provides an air seal adjacent to the terminal without providing a pressure seal within the receptacle.

Abstract: A circuit breaker having a magnetic trip mechanism pivotally mounted on the bimetal actuating assembly. First and second flanges extend from the bimetal element and respectively include first and second co-axially aligned apertures. A magnetic trip arm is pivotally mounted in the first and second apertures and includes a first portion disposed in proximity to the bimetal element to be drawn thereto in response to a high overload current flowing therethrough and a second portion which engages a latch, upon movement of the magnetic trip arm, thereby tripping open the contacts of the circuit breaker.

Abstract: An over-center toggle switch suitable for use in an electrical distribution transformer as a series-multiple switch or as a no-load tap changer switch. The over-center toggle switch imparts snap action rotation to a movable contact assembly and, further, cams the movable contact assembly immediately prior to the snap action movement thereby causing an initial rotation of the movable contact assembly. In multiple phase distribution transformers, individual over-center toggle switches are associated with each phase and are interconnected by suitable connecting means to an operating mechanism whereby rotation of the operating mechanism through a predetermined angle causes independent operation of each over-center toggle switch which thereby imparts camming and snap action rotation to the movable contact assemblies in each phase of the distribution transformer.

Abstract: An electrical load break bushing having a movable tubular conductor therein, engageable with a contact pin of an electrical connector, is arranged to minimize the duration of arc during load-make and load-break operations. A locking member holds the tubular conductor in a first, normally-open position until the contact pin engages the tubular conductor whereon the mated tubular conductor and contact pin assembly move toward a second, normally-closed position. A second contact, adapted to engage the tubular conductor, is supported by the bushing at the second position and is disposed within the dielectric fluid surrounding an electrical apparatus such that an electrical circuit is completed within the dielectric fluid. During a load-break operation, interlock pins prevent the tubular conductor and contact pin from disengaging until the tubular conductor has separated from the second contact whereby the electrical circuit is broken within the dielectric fluid.

Abstract: Cylindrical tap terminals are attached to a base plate and are positioned symmetrically around an opening in the base plate. A contact carrier is positioned in the base plate opening and is dimensioned for rotation therein. A movable contact blade is disposed in a radial opening in the contact carrier and is dimensioned to connect together two adjacent tap terminals. A shaft with an inclined surface thereon extends into another opening in the contact carrier and is coupled to an operating handle. The handle may be pulled to move the inclined surface and permit movement of the contact blade away from the tap terminals. Rotation of the handle rotates the shaft, the contact carrier, and the contact blade to another position. When in position, a coil spring forces the inclined surface against the contact blade to maintain adequate electrical contact pressure between the blade and the tap terminals.