GB581194A - Improvements in or relating to electric circuit breakers adapted for rapid reclosure - Google Patents

Abstract

581,194. Automatic circuit-breakers. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. April 19, 1944, No. 7269. Convention date, May 30, 1942. [Class 38 (v)] A circuit-breaker which can be closed manually or automatically, is operatively related to, and under the control of, power closing mechanism at all times, and the trip means is operative at any position of the manua closing means and instantly operative to permit reversa of the power closing means The movable contacts 11 are attached through lever 19, tc an operating rod 25 pivotec at 63 to an operating lever 49 interposed between levers 41 constituting a manual closing lever 39. The latter is pivoted to lever 49 at 51 anc to the casting 27, and is locked by spring-latch 55 The lever 49 is similarly locked by a latch 75 which is pivoted at 77, and biassec anti-clockwise by spring 79 An auxiliary latch 81, also biassed anti-clockwise keep: latch 75 in the locked posi tion until extension 89 is moved upwards by the rod 91 of a tripping electromagnet 93, such action releasing lever 49 and opening the breaker. A lever 101, biassed clockwise, and allowed to move when the latch 75 is released, holds the auxiliary latch open by projection 107 until the breaker is reclosed. The closing operation is effected by passing compressed air through valve 115, Fig. 3, into a cylinder 29 thus moving piston 35 downwards. Valve 115 is operated by the electromagnet 123 actuated through relays by a fault on line 13. 'A second valve 129, placed between valve 115 and cylinder 29 in order to throttle the air-flow, is biassed to an open position by spring 130, and is closed by the piston near the end of the opening stroke. Upon closing, a projection 132 reopens the valve to allow the finish of the stroke to be rapidly effected. To make the breaker power trip-free, an exhaust port 133 in the cylinder leads to exhaust passage 135 through a dump valve 137, the electromagnet 141 of which is connected in parallel with the tripping electromagnet 93 by contacts 183 of trip relay 185, Fig. 5. On overload the latch 75 is tripped, contacts 201 are momentarily closed, and the biassing spring 15 opens the contacts 11, at the same time closing contact 203 in the circuit relay 193, which is energized before contacts 201 reopen due to de-energization of relay 185. Closure of contacts 195 of relay 193 energizes relay 0, which in turn energizes electromagnet 123, thereby supplying air through valve 115. This air quickly moves the piston down again to reclose the breaker substantially instantaneously. If the overload persists, the opening operation is repeated, but the breaker is prevented from reclosing again by a lockout device 205. The breaker is reclosed by operating switch 167, which energizes relay 0 to operate valve 115 through electromagnet 123. The provision of the exhaust port 133 permits the breaker to reverse its movement while still not completely closed. The breaker may be tripped manually by closing a switch 191, thus energizing trip device 93, or by trip lever 207. If desired, the breaker may be manually closed by moving latch 55 to the release position, and then moving lever 39 about its pivot anti-clockwise until the free end of lever 49 is reheld by latch 75. The lever 39 is then moved down again until it is relatched by latch 55. Specification 548,438 is referred to.