CONTROL CIRCUIT FOR SWITCHING DEVICES PROTECTING CAPACITORS SERIES-CONNECTED IN HIGH VOLTAGE LINES

摘要

1,122,311. Protective arrangements. ENGLISH ELECTRIC CO. Ltd., and BRITISH INSULATED CALLENDER'S CABLES Ltd. 27 Sept., 1966 [27 Sept., 1965], No. 40946/65. Heading H2H. A circuit to protect a polyphase series transmission line capacitor bank 1, 2 on the occurrence of high voltage or current or a persistent overcurrent comprise spark gaps 4, 5 which on over voltage spark over and energize a definite time relay 13 and a line current transformer which energizes an inverse time delay relay 14 on overcurrents, and a low current relay 15. The circuit includes a pressure responsive switch 16, the opening and closing coils 7, 8 and spring charging motor 10 for a circuit breaker 6, all three breakers being closed simultaneously by an interphase trip 17. The circuit breakers in all phases are closed by persistent arc over low air pressure, line current overload, or low line current.