GB564128A - Improvements in and relating to electric circuit-interrupter control systems - Google Patents

Abstract

564,128. Switches, partly electromagnetic; actuation of switches. BRITISH THOMSON-HOUSTON CO., Ltd. Feb. 10, 1943, No. 2199. Convention date, Feb. 13, 1942. [Class 38 (v)] The control circuit for the motive means of a circuit-interrupter is de-energized and held de-energized when the motive means has accomplished a given part of its movement, so as to prevent pumping if the operator's switch is retained closed and the interrupter trips out again at once. To close, operator's switch 40, or automatic reclosing switch 41, is closed to energize an electromagnet 27, 28 which attracts a light armature 29 and at 35 energizes a solenoid 23<1> which, at 43, makes a maintaining circuit for winding 28, and operates a valve 15 supplying closing fluid to the piston 12. When the latter reaches point 49, fluid passes through check valve 50 to a piston 46 which pushes heavy armature 30 into the position where it is held by the electromagnet 27 provided the switch 40 is still in closed position. Simultaneously contacts 39 open the circuit of solenoid 23<1> to permit valve 15 to close and also to prevent re-energization of solenoid 23<1> and so cause pumping if the interrupter trips open before switch 40 is opened. Opening of the interrupter is effected by a valve 18 operable by a solenoid 21 subject to circuit conditions, and to ensure that opening takes precedence over closing, a further conduit and check valve 51 admits fluid to operate piston 46 and armature 30 so as to de-energize the closing solenoid 23<1>. Where it is possible to mount the electromagnet 27 near the interrupter, armature 30 may be operated through a push rod operated by a cam on piston rod 13, there being a. similar piston to 46 for ensuring that opening takes precedence over closing. The Specification refers also to electric motor and solenoid operation of the interrupter.