Patent GB-196246-A (GB)
Title: Improvements in and relating to automatic reclosing electric circuit breaker systems
IPC: H02H3/06
Filed: 1923-01-31
Abstract: 196,246. British Thomson - Houston Co., Ltd., and Anderson, A. E. April 15, 1922, [Convention date]. Cut-out arrangements.-In an automatic re-closing system for a plurality of circuit-breakers. the circuit-breakers are closed in groups of one or more at a time and the groups in succession so that a small battery or other source may be used for the purpose. The circuitbreakers are automatically reclosed a predetermined number of times and, if the overload on any one or more of them persists thereafter, such circuit-breakers remain open without affecting the automatic operation of the others. As applied to two circuitbreakers 2 re-closed in succession and shown in the closed position, on the occurrence of overload the relay 9 in the circuit 1 is closed to complete a circuit from the auxiliary source 7 through the contacts 8 to energize the tripping coil 6. In the open position, the circuit-breaker bridges contacts 18 and a circuit is completed through the coil 20 of the starting relay, across the normally bridged contacts 21 of a lock-out relay, through the normally closed contacts 34 of a hand-controlled switch 33 and through the contacts 18 back to the auxiliary source. The starting relay is consequently closed, bridging the contacts 19, 23, 28 thereby causing the energization of the starting bus-bar 29 and the consequent operation, by the solenoid 16, of a latch 14 which normally holds a selector drum 11 against the continuous torque of a motor 13 supplied from the main circuit. The drum carries groups of contacts co-operating with contacts 17 and 24, and, when released, rotates through one revolution until again held by the latch. When the particular set of contacts 17 in the circuit (through the contacts 19 and contacts 35 of an alternative hand-operated switch 31) of the closing relay 10 are bridged, the relay is closed and the closing coil 5 energized to re-close the open circuit-breaker. Each open circuit-breaker is closed twice in the arrangement shown, one at a time and each in succession, and, finally, the drum bridges the contacts 24 and completes the circuit of the lock-out coil 22 which opens the lock-out circuit 21 and automatically retains it open thereby breaking the circuit of the coil of the starting relay 20, the circuit of the closing relay 10 and that of the coil 16. The latch thereupon becomes effective to retain the drum and subsequent movement thereof will not re-close the locked-out circuit-breaker, which must be restored by hand. By depressing the hand switch 31 a shunt circuit supplying the closing relay 10 is closed to close the circuitbreaker which may be tripped manually at will by depressing the switch 30 providing a shunt circuit for the tripping coil. To ensure that the manual tripping does not bring into action the selecting device 11 the switch 30, in closing, breaks at 34 contacts in the circuit of the starting relay. In a modification for a large number of circuit-breakers, a master selecting switch controlling the release latches of a number of auxiliary selecting switches is employed.