GB738528A - Air blast electric circuit breaker - Google Patents

Abstract

738,528. Air-blast circuit-breakers. ALLMANNA SVENSKA ELEKTRISKA AKTIEBOLAGET. June 1, 1953 [May 31, 1952], No. 15156/53. Class 38 (5). A plurality of circuit-breakers similar to that of Specification 713,798 are connected in series and are arranged in pairs in separate containers mounted on separate insulators, the containers being in communication with each other and compressed air being supplied through at least one delivery pipe to the containers. As shown in Fig. 1, three containers 7 ... 9 are mounted on insulators 1 ... 3, air being supplied to the container 8 via a pipe E and thence to containers 7, 9 via pipes 16, 17 which also serve to connect the circuit-breakers 10... 15 in series. Condensers 20 ... 25 are connected in parallel with the contact gaps to divide the voltage evenly. The contact-operating mechanisms 30 ... 35 are supplied with air via pipes 36 ... 38. Fig. 3 shows an enlarged view of mechanism 33. The moving contact 47, which is carried by a piston 49, is separated from the fixed contact 40 by supplying compressed air via pipe 37 to a membrane 64 which changes over a valve 70 to vent the underside of a piston 56. At the same time, air is supplied to the underside of a piston 54 so that a cylinder 50 carried thereby is moved upwards to open an outlet opening 53 so that the housing 45 is evacuated. The contact 47 is thus moved down by the pressure around it in the container 8 until a collar 73 meets the upper end of cylinder 50. The arc formed is extinguished by air flowing between the contacts. Air is also supplied over a throttle valve 66 to the upper side of piston 54 to reclose the opening 53, the contact 47 following, to insert an isolating gap, until piston 49 abuts a sealing ring 61. To reclose, the pipe 37 is evacuated so that valve disc 70 moves to the right and air is supplied to the space below piston 56 which is moved upwards to reclose the contacts by means of a rod 57.