Patent GB-959858-A (GB)
Title: Improvements in or relating to electric systems of remote supervision
Inventor: POPE BERNARD WALTER
IPC: H02J13/00
Filed: 1962-04-04
Abstract: 959,858. Electric selective signalling. GENERAL ELECTRIC CO. Ltd. May 21, 1963 [April 4, 1962], No. 12977/62. Heading G4H. Equipment for use in an electrical remote supervision system comprises a plurality of record members each of which, when placed in a predetermined position on the equipment, selects one of a plurality of channels and supplies to it a signal which selects one of a plurality of substations on the channel, the selected substation responding by transmitting a sequence of supervisory signals representing the conditions of apparatus units at the substation, these conditions being indicated by individual visual means, the record member carrying a plurality of visual indicators which can be adjusted manually to obtain correspondence with these visual means. In the particular embodiment, said equipment is a standby supervisor, portable in several interconnectable parts (e.g. Fig. 2), to take the place of a central station in case of line breakdown. The visual indicators on the record members are rotatable dummy switches. Each channel consists of wires referred to as the incoming, outgoing and supervisory pairs although the wires of a given pair are connected together at their outward extremities. Indication cycle. The record member (Figs. 3,4, not shown) corresponding to a particular substation is placed in a bracket 23 and pressed forward so that a projection on it closes one of several micro-switches, e.g. 29, to select a channel, and a second projection closes one of several more micro-switches, e.g. 30, to select a substation on the selected channel. Other projections accomplish routine functions e.g. energize electro-magnets 34, 35 to hold the record member in place. The supervisor reverses and restores the direction of current flow in the outgoing pair a number of times depending on the required substation, the selected substation responding by connecting D. C. to the incoming pair and interrupting it a number of times to light one of four lamps 46-49 which indicates the substation. The supervisor then reverses and restores the current in the outgoing pair a number of times to scan, in turn, circuit breakers at the substation, the condition of each circuit breaker being signalled, in terms of the direction of the current in the incoming pair, to the supervisor to energize one of a corresponding pair of relays. If the state thus signalled is not the same as that of a control switch e.g. 14,15 or 16 at the supervisor for the circuit breaker, a lamp 20,21,22... in the control switch is lit. The control switches 14,15,16... are then turned manually where necessary to extinguish their lamps. Control cycle. If, following the above indication cycle, it is desired to change the state of a circuit breaker at the substation, the corresponding control switch 14, 15, 16... is turned, thus initiating an indication cycle. When, during this, the scanning of the circuit breakers reaches the one to be changed, the lamp 20, 21, 22... in its control switch 14, 15, 16... lights and at this instant one of two buttons 40, 42 (depending on the desired state) is pressed. This results in a negative voltage being connected to both wires of the incoming pair and positive to one wire of the supervisory pair, a series of current reversals in the outgoing pair then achieving the change of state. This shange of state is shown at the supervisor by lamps in the buttons 40,42 one of which is lit when the circuit breaker is open and the other when it is closed. Uncontrolled change. If a circuit breaker changes state other than as the result of a command signal from the supervisor, current normally flowing in the supervisory pair of its channel is interrupted with the results that a bell rings, lamps 45 flicker, and one of the lamps in the row 50, 51... lights to indicate the channel. The substations of that channel are now scanned in turn by current reversals in the outgoing pair, the substation with the changed circuit breaker responding by reversing the current in the incoming pair a characteristic number of times with the result that one of the lamps 46-49 lights to indicate the substation, and the scanning stops. The record member appropriate to the indicated substation is now inserted. The control switches 14, 15, 16... are rotated to agree with the dummy switches on the record member which had been set during the last indication cycle for that substation to show the states of the circuit breakers before the uncontrolled change. A new indication cycle now starts, the circuit breaker which has changed state being identified by which of the lamps 20, 21, 22... lights. Figs. 5-17 (not shown) show circuit diagrams of the supervisor and of a substation. Specification 746,069 is referred to.