MEJORAS EN O RELATIVAS AL FUNCIONAMIENTO DE CONMUTADORES EN CIRCUITOS DE SUMINISTRO DE ENERGIA ELECTRICA

摘要

645.333. Protective cut-out systems. STANDARD TELEPHONES & CABLES. Ltd. Feb. 2, 1945, No. 2663. [Class 38 (v)] In an automatic circuit-breaker reclosing eauipment, provision is made whereby after four automatic reclosures consequent upon the occurence of a prolonged fault, the reclosing mechanism is locked out and the circuit-breaker remains open. When the breaker first trips, auxiliary contacts BAC change over releasing a relay AP and energizes a slow release relay G in the breaker control circuit, whereupon contact ap3 in a timing circuit energizes a timing condenser QC which begins to charge until at the firing voltage of a cold cathode tube CCT, a relay P is energized. A relay A in a relay counting-train is thus operated over closed contacts g1, p1. aa2. thereby closing contact a3 and operating a breaker closing relay CL. Contacts BAC are restored and relay AP re-energized, releasing relay P and discharging condenser QC, while in the counting-train, a relay AA is operated and relay A holds until slow release relay G drops out and returns the circuit to normal. If the fault persists, however, the breaker again trips immediately. Second trip.-Relay AP is again released firing tube CCT and operating relay P which now operates a relay B, relay A being released at contact p2. Relay CL again closes the breaker whereupon relay AP again releases relay P, releasing relay AA at contact p2. Relay B locks and a relay BB operates. Third trip.-Relay A operates in turn operating relay CL again. Relay AP operates and relay P releases and operates relay AA. Relays A, B, BB are now held. Fourth, trip.-Relays A, B are released at contact p2 whereupon relay CL again operates and relays AA, BB are released at contact p2. This locks relay AP over contacts g2, aa4, bb4, ap2. Fifth trip.- The locking circuit for.relay AP completed by the above sequence of operations, prevents relay AP from releasing and the breaker remains open with all the other relays released until it is closed by a local circuit, when relay G will release and the circuit will be reset. The charging time of condenser QC may be adjusted by a variable resistance YCC. The trips may alternatively be counted by a condenser-charging and cold cathode tube circuit.