GB1018251A - Improvements relating to high voltage gas-blast electric circuit breakers - Google Patents

Abstract

1,018,251. Gas blast switches. A. REYROLLE & CO. Ltd. Sept. 3, 1962, No. 33768/62. Heading H2B. In a gas blast circuit breaker of the type in which the main contacts 12, 16 are in a chamber 11 permanently filled with compressed gas and an impedance 43 is switched in parallel with the main contacts during each opening operation, the gas blast is initiated by a valve 21 opened when the contacts 12, 16 open and is stopped by a second valve 46 whose moving member carries the contacts 49 of the impedance switch. In a first embodiment (Fig. 1, not shown) valve 21 is rigidly coupled to moving contact 12 and they are opened by venting cylinders 24, 30 through a control valve 53. Valve 53 also supplies compressed air through a pipe 64 to move valve 46 a short while later to separate resistor contacts 49, 50 and then to close the exhaust 67. The contacts are reclosed by repressurizing cylinders 24, 30 through valve 53, an extension of the rod 27 of valve 21 ensures that valve 46 is opened and the resistor contacts closed. In a second embodiment (Fig. 2) both the main contacts 103, 104 and the resistor contacts 119, 120 are housed in the gas-filled chamber, the blast is initiated by a valve 135 which also vents cylinder 107 to move a piston 106 to open main contacts 103, 104. A rod 153 couples piston 106 with a valve 150 which allows compressed gas to enter above a piston 114 driving the latter downwards first to open resistor contacts 119, 120 and then to close exhaust valve 130 to stop the blast. The contacts are reclosed by repressurizing cylinder 136 to reclose valve 135 when cylinder 107 is refilled with gas via flap valve 141 and the parts are returned to the positions shown.