Patent GB-809187-A (GB)
Title: Improvements in or relating to automatic reclosing electric circuit interrupters
IPC: H01H75/04
Filed: 1957-05-17
Abstract: 809,187. Automatic reclosing circuit-breakers; oil-blast switches; protective cut-out arrangements. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. May 17, 1957 [May 28, 1956], No. 15740/57. Class 38 (5). A multi-pole automatic-reclosing circuit interrupter has a plurality of interrupter units 20, a common operating mechanism including a toggle linkage 89, 91, 94, Fig. 3, having two movable pivots 92, 95, a releasable latch 100 for holding the linkage extended to maintain the interrupter contacts closed against the opening bias of a spring 86, an overcurrent trip device 22 associated with each unit 20 and connected through an individual time delay means 32, Fig. 4, to the latch, and an automatic reclosing means including a rotatable member 145 operatively connected to one pivot 92 of the linkage to reclose the interrupter at a predetermined time interval after the release of the latch. In the arrangement shown, oil blast interrupter units 20, bushing type current transformers 207 and the overcurrent trip devices 22 are housed in an oil-filled tank 25, the units 20 and the devices 22 being connected by suitable linkage to the operating and tripping mechanism in an air-filled tank 29. The time delay means are diaphragm-type air dash-pots and act on a common trip bar 196. When the trip bar is operated it turns a trip lever 115 to " break " a toggle 110, 107 to release the latch 100. The resulting upward movement of the pivot 95 permits the toggle 89, 91 to break downwardly so as to open the interrupter and at the same time reset the link 94 and latch 100 to the position shown. A further time delay device 200 operated by linkage 202 from the common interrupter operating shaft 70 operates a switch 205 after a delay and so completes a circuit for an electric motor 150. The motor drives a shaft 146 which carries a roller 145 into, engagement with a shoulder 143 on a closing link 136 to raise the link to effect the resetting of the toggle 89, 91 and the reclosing of the interrupter, contacts 147, 148 maintaining the motor circuit closed until the reclosing operation is complete. Initially the time delay devices 32 are ineffective in delaying the tripping of the interrupter on overload, but after a desired number of opening operations a counter 216, Fig. 13, acting through linkage 190, 184 closes valves in the devices 32 to make the devices effective to delay subsequent tripping operations. After a desired total number of tripping operations, the counter opens contacts 240 to prevent the energizing of the motor and so locks out the interrupter. The current transformers 207 energize an earth fault trip 3421 which acts on the common trip bar 196 through a time delay device 206. The interrupter may be tripped by a shunt solenoid 120, Fig. 3, or by means of a manually-operable lever 128, the solenoid and lever acting on the trip lever 115 through an intermediate lever 124 which also moves the counter to the lock-out position to prevent automatic reclosing. Reclosing may then be effected by closing a switch 252 to by-pass the lock-out switch, or manually by turning a lever 1281 so that a roller 126 engages the end of a lever 132 and raises it to reset the toggle 89, 91. The Specification illustrates and describes in detail the various components of the interrupter.