GB747624A - Improvements in or relating to electrical systems of remote control - Google Patents

Abstract

747,624. Switching systems. GENERAL ELECTRIC CO., Ltd., and SMART, N. C. June 2, 1954 [June 1, 1953], No. 15188/53. Class 38 (4). A system for the control and supervision of a substation circuit breaker from a distant control point comprises, at the substation, O C (1) relays -, - having, respectively, contacts, 2 2 02, C2 controlling the opening and closing coil circuits for the circuit breaker and (2) a changeover switch S actuated by the arcuate breaker and which, according as to whether the breaker is open or closed, impresses on the line L1, of a pair of lines connecting the substation and control point, a positive or negative potential from sources 1, 2, respectively. At the control point are a number of sources of potential, the connection of which to lines L1, L2 and to an indicator lamp EL are controlled by a four-position rotary control switch having contacts 20-28, and three relays. The Figure shows the control switch in its second, or " open indicate " position, wherein contacts 23-25 . are closed and a source of negative potential from a source 5 is connected to line L1 over contact 23. If this source assists that connected to the line over changeover switch S-Indicative of correspondence between the control switch position and the circuit AL breaker condition-relay - is operated and 2 its open contact AL1 prevents the lamp EL being flashed by an intermittent voltage source 9. If there is lack of correspondence, source 5 opposes that connected by switch S, AL relay - is not energized and the lamp flashes. 2 Movement of the control switch to its third position (" closed indicate "), to restore correspondence. opens contacts 23-25 and closes 26-28, thereby substituting for the source 5 a source 6 of opposite polarity to cause the relay to operate and stop flashing of the lamp. Change-over of the circuit breaker from one condition to the other is effected by moving the control switch through the other " indicator " position into one or other of its first, or fourth, positions, which are non-locking, thereby closing contacts 20-21 in addition to either the contacts 23-25, or 26-28 associated with the adjacent " indicator " position " two " or " three ". Relay OP/2 is momentarily energized over contact 22, whilst a slugged relay DA/1 is releasing, to connect the line L1 over contact OP2 and 24, or 27, to a voltage source sufficient O C to actuate the relay - or - by winding 17 or 2 2 18. The relay then locks in, over winding 16, or 19, and holding contact 01, or C1 supplied from a circuit including switch contact 20, and effects the change-over of the circuit breaker by closure of contact O2 or C2. At initiation of change-over lamp EL was continuously energized from a source 11, 12 over relay contacts AL2 and switch contact 21. On completion of change-over AL/2 responds and disconnects the lamp. The control switch may then be released and it moves to the adjacent " indicator position. The line L2 may be common to a number of similar circuits controlling several circuit breakers.