GB572709A - Improvements in and relating to automatic reclosing circuit breaker systems - Google Patents

Abstract

572,709. Protective cut-out arrangements. BRITISH THOMSON-HOUSTON CO., Ltd. June 22, 1943, No. 10036. Convention date, June 23, 1942. [Class 38 (v)] A circuit-breaker suitable for distance-protection is adapted to be reclosed after a time dependent on the time elapsing between the occurrence of the fault and tripping, whereby, in a system with means for tripping at once for faults in the section and with two stages of time-delayed tripping for faults in successivelyremote sections, instantaneous or delayed reclosure (or lock-out) can be obtained, Faultresponsive means has instantaneous contacts Z1 corresponding to faults in the section and time-delayed contacts Z2, Z3 for remote faults. Closure of Z1 produces tripping followed by energization of the instantaneous reclosing means 14 over auxiliarv breaker-contacts 11. Closure of Z2 or Z3 produces tripping also, and relay 18 energizes a relay 13 which cuts out the reclosing means 14 at contacts 12, and at contacts 19 and auxiliary breaker-contacts 20 energizes a reclosing means 21 of the kind set out in Specification 196,246, [Class 38 (v)]. Relay 13 is latched in the attracted position and released by solenoid 26 when the means 21 closes contacts 24 and provided breaker contacts 27 are closed. The reclosing coil 16 is thus energized alternatively by contacts 15 or 22 of the means 14 or 21, respectively. In Fig. 3, the timer 21 is replaced by an automatic synchronizing and reclosing means 30 energized over auxiliary breakercontacts 20 and contacts 19 of relay 13 in the attracted position. Reclosure of the breaker effects at contacts 33 energization of time-delay relay 32 which makes the circuit of coil 26 to reset the relay 13. Delayed reclosure may also be subject to voltage-conditions on either side of the breaker, as set out in Specification 292,957, [Class 38 (v)]. The Specification as open to inspection under Section 91 described and illustrated, Fig. 3 (cancelled) (not shown) an arrangement in which instantaneous and delayed reclosures are all provided by the means 21, which is cut out by operation of relay 18 so as to be ineffective on delayed tripping of the breaker, that is, for faults outside the section. This subject-matter does not appear in the Specification as accepted.