Abstract: Access to the arc chutes of a contactor is provided by mounting the arc chutes along with insulating plates on the top surface of a frame which supports the parts of the contactor. A track is formed as a pair of grooves in a top surface of the frame. The arc chutes have projections on each side which fit into the grooves of the track so that the arc chute may stand on the top surface of the frame of the contactor. Insulating plates are mounted in sockets made into the top surface of the frame and provide electrical insulation for the arc chutes.

Abstract: The inventions solves the problem of convenient mounting of parts of controllers, and solves the problem of interchangeability of vacuum and air break contactors within a controller. A controller has a housing, an isolation switch mounted within the housing, a contactor mounted within the housing and connected electrically downstream from the isolation switch, and the controller has a receptacle which can accept either a vacuum contactor or an air break contactor. Also, the contactor has an operating coil and control components mounted on a side facing a door of the housing so that the coil can be replaced and the control components serviced without disturbing the contactor.

Abstract: Warping and twisting of the armature of a polyphase alternating current air break contactor is reduced by mounting the operating coil near the middle of the armature. A polyphase alternating current air break contactor has a frame, an armature having two ends, the ends being rotatably mounted within the frame so that the armature may rotate within the frame, at least three movable contacts and at least three stationary contacts forming a contact pair of each phase of the polyphase alternating current, and the contactor has an operating coil for the armature mounted in the frame substantially midway between the two ends of the armature.

Abstract: The invention solves the problem of loss of contact between jaws of a stationary contact with a switchblade of a knife switch when the switchblade undergoes lateral motion, as for example, under the influence of electromagnetic forces during short circuit conditions. A jaw for a switch has a base, a pair of electrically conducting jaws for accepting a blade of a switch between the jaws, a pin mounted in a hole passing through the base; retention springs mounted on the pin and producing force against the jaws so as to maintain electrical contact between the jaws and the switchblade, wherein the pin may slide in the hole in the base so that the jaws may follow lateral motion of the switchblade.

Abstract: The electromagnetic forces tending to force open the contacts of an electromagnetic contactor are reduced by providing a current flow path having a geometry that tends to minimize the magnetically produced forces acting upon the movable contact of an electromagnetic contactor. A contactor has a frame, a stationary contact attached to the frame, a first conductor supplying the stationary contact, an armature rotatably mounted in the frame, a movable contact attached to the armature, and a second conductor supplying the movable contact. An arm has a first arm end supporting the movable contact and a second arm end attached to the armature.

Abstract: The invention has an enclosure, a circuit breaker mounted inside the enclosure, and a hand lever rotatably mounted upon a door of the enclosure. A drive shaft is rotatably attached at a first end to the circuit breaker so that rotation of the drive shaft operates the circuit breaker. When the door is closed a second end of the drive shaft seats in a socket in the hand lever, and rotation of the hand lever rotates the drive shaft. A spring clip is mounted within the hand lever, and the spring clip grips the second end of the drive shaft so that force applied by the hand lever to rotate the drive shaft may deform the spring clip thereby permitting deflection in a coupling between the hand lever and the drive shaft. A retainer plate attached to the hand lever catches the drive shaft when the spring clip is deformed by the force and thereby prevents opening of the door as a safety measure. The drive shaft has a reduced cross-section region between the first end and the second end.

Abstract: A high voltage motor starter enclosure includes a floor mounted vertical section consisting of three starter cells, stacked one on top of the other, each cell being suitable to mount one full voltage, non-reversing, squirrel cage starter having a contactor of the air break type.