Patent GB-264472-A (GB)
Title: Improvements in electrical signalling and/or controlling systems
IPC: H02J13/00
Filed: 1926-12-20
Abstract: 264,472. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Ostrolank, S., and White, T. U.). Jan. 16, 1926, [Convention date]. Selective distant-control systems tell-tale apparatus. - Relates to a system for supervising and controlling the operation of apparatus, such as circuit breakers, at a substation of the type wherein upon the operation of a key or the automatic change in position of an apparatus unit, the units are successively connected to corresponding control keys and signalling lamps over common line wires, the desired control or signalling operation being effected at a point in the cycle of operations corresponding to the relative position of the operated key or unit. The apparatus units and their corresponding control keys and supervisory signals are connected to groups of contacts which are successively operated by synchronously driven stepby-st.ep cam shafts at each station. Fig. 1 shows the apparatus at the control office and Fig. 2 the substation apparatus. Each circuit breaker such as C is in turn associated with its corresponding key, such as 144, and supervisory lamps 2, 3 over common control and signalling lines c, s, by groups of contacts 12 - - 15. 22 - - 26 - - and 212 - - 215, 223 -- 226 - - - which are operated successively by pins 11 - - 101, 211 - - 301 on the cam discs 10 - - 100, 210 - - 300 of the synchronously driven shafts 120, 220. This arrangement facilitates simple variation of the capacity of the system by altering the number of cams and associated groups of contacts. The shafts 120, 220 are driven by stepping electromagnets 36, 236 which are controlled by the pairs. of line relays 18, 28 and 218, 228 adapted to be alternately connected to a line wire d and operated by impulses of opposite polarity. This arrangement ensures synchronous rotation of the shafts 120, 220 for in the event that the shafts become out of step corresponding line relays at each station are not associated with the line d and the selecting operation is held up. Each unit has a key KS which when operated stops the cycle of operations at a point corresponding to the unit and thereby allows the operator to remain in connection with the selected unit indefinitely. Normal condition of system. When the apparatus is at rest, a relay 84, Fig. 1, is energized in series with a relay 274, Fig. 2, over the line c and the normally operated contacts 13, 213 in the first groups of cam-operated contacts. The relay 84 prepares the circuit of the relay 85. Initiation of operation of selecting apparatus. The operation of the selecting equipment is started by a key K which is depressed to energize the relay 85 over the contacts 15 and thereby open the series circuit over the normally energized relays 84, 274 at the armature 92 and prepare a circuit over the line d at the armature 95. When the relay 274 at the substation is de-energized, a relay 273 closes the circuit of the relays 18, 218 over the line d. The relays 18, 218 operate the stepping magnets 36, 236. The magnet 36 energizes the relay 87, the circuit of which is prepared by a normally energized relay 86, to open the circuit of the line relays. Upon deenergization of the line relays the electromagnets 36, 236 are de-energized to move the cam shafts 120, 220 forward one step. This operation opens the groups of contacts 12 - - 15, 212 - - 215 and closes the next groups 22 - - 26, 223 - - 226. The contacts 22 shortcircuit the relay 86 which de-energizes after an interval and releases the relay 87 which again closes the line d. Due, howover, to the operation of the second groups of contacts the line relays 28, 228 are energized in series to again operate the stepping magnets. The relay 28 also opens the short-circuit across the relay 86 so that the relay 87 is again operated to open the line d and permit a second step of the cam shafts. The line relays 18, 218 are associated with odd groups of cam contacts and the relays 28, 228 with even groups so that the above-described cycle, of operations is repeated to close and open the remaining groups of contacts at each station successively. The " start relay 85 is held locked during the operation over the normally closed contacts 102 in the last group so that when this group is operated the relay is de-energized to. open the line d and thereby move the cam shafts a further step to again close the first groups of contacts. The closure of these contacts together with the de-energization of the relay 85 completes the normal series circuit over the relays 84, 274. Operation of circuit breaker C. In order to operate the circuit breaker, the control key and the common master key KM are operated in the appropriate directions. When the corresponding groups of cam contacts are simultaneously operated, a circuit is completed over the contacts of the keys, cam contacts at the control office, line c, cam contacts at the substation and one or other of the relays 287, 288 depending upon the existing position of the circuit breaker. These relays control the " closing " and " opening solenoids 285, 286 respectively. If desired, the operator can remain in connection with a circuit breaker by operating, at the commencement of the cycle, the appropriate " stop " key KS. This key opens the short-circuit path of the relay 86, so that when the proper groups of cam contacts are operated, the relay 86 and in consequence the relay 87 remain energized to hold open the driving circuit over the line d and thus prevent further operation of the apparatus. Restoration of the stop " key re-starts the operation. Supervisory signalling. When the circuit breaker is operated under the control of its key, a relay 276 is energized or de-energized to close a circuit over the supervisory line s for one or other of the relays 4, 5 which control the supervisory lamps 2, 3. If, subject to load conditions, a circuit breaker is automatically operated, a relay 275 is operated to open the normally closed circuit over the relays 84, 274 and initiate the cycle of operations in the manner previously described. A signal of the changed condition is transmitted when the appropriate groups of cam contacts are operated. A lamp 1 is associated with each group of contacts at the control office in order to indicate the position of the cam shafts at any instant during the cycle. One or other of the relays 7, 8 is energized upon the receipt of a supervisory signal to open the control circuit.