Abstract: An electrical terminal includes first and second members having elongated complementary arcuate surfaces thereon movable toward and away from each other by a clamping member. The second member is pivotally supported at one end on the first member and is configured so that different diameter conductors can be securely clamped between the arcuate surfaces.

Abstract: An electronic circuit breaker having a trip solenoid assembly. The trip solenoid assembly includes a permanent magnet, plunger, trip coil and assist coil and is positioned adjacent to a phase conductor. At high current levels the phase conductor generates a flux that may cause the circuit breaker to nuisance trip. An assist coil is wound adjacent the trip coil. The assist coil is energized only when the current through the circuit breaker is of such a level so as to cause nuisance tripping. The assist coil is not energized during that time period when the trip coil is energized.

Abstract: An electrostatic fork shield for a layer wound transformer yielding a high degree of noise attenuation. A three phase transformer has three leg portions which are interconnected at both ends by a yoke. Around each leg portion is wound layers of primary coil and secondary coil. The transformer core, coils and shields lie within an enclosure. Both the inner wall and outer wall of each transformer coil is covered with a non-ferrous conductive shield. Between the primary and secondary coils of each phase and their respective vertical shields, is interposed a glastic spacer. A horizontal shield lies across each end of the transformer coil. The horizontal shield comprises a base and inner and outer fingers which cover a large portion of the surface of the coil ends but do not form a complete electric path around any leg portion. Two barrier shields are located on one side of the transformer between adjacent phases and are connected to the inner fingers of each horizontal shield.

Abstract: A self-contained test feature for ground fault protection systems in circuit breakers. The ground fault protection system includes a sensing transformer having a primary winding that sums the currents through the phase current transformers. Upon the occurrence of an actual ground fault, the sensing transformer will transmit a signal to cause the breaker to trip. The test feature includes a test transformer having its secondary winding electrically connected in parallel with the primary winding of the sensing transformer. The current path between the test transformer secondary winding and sensing transformer primary winding is completed only upon the activation of a test switch. The primary winding of the test transformer is hooked to an external current source to provide the necessary current to simulate the ground fault.