Patent GB-198699-A (GB)
Title: Improvements in control systems for electrical distribution systems
IPC: H02J13/00
Filed: 1923-06-05
Abstract: 198,699. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Wensley, R. J.). June 5, 1922, [Convention date]. Selective distant -control systems. - A supply system is divided into sections by means of interrupters which are selectively controlled from a central station by means of a step-by-step selector switch. The controlling impulses of the selector switch are transmitted over a telephone circuit and audible means are provided at the central station to indicate the condition of an interrupter. When a fault occurs on a section it can be located and the section isolated. Conductotis 12, Fig; 1, wihich may connect two bus-bar sections 10, 11 or constitute a loop from the same bus-bars, are divided into sections by means of interrupters 13, 14 and 15 controlled by units 20, 21. and 22. The control units are operated by current impulses transmitted over a telephone circuit 18 by means of a dial switch 19 similar in construction to a subscriber's calling switch on an automatic telephone, system. Each control unit comprises an arm 40, Fig. 2, carrying contacts 41, 42 and 43 adapted to engage groups of stationary contacts 1, 2, 3, and adapted to be operated in a step-by-step manner by means of a magnet 36 and to be released from its operated position by means of a magnet 55. The arm 40 normally occupies the position X. To close the interrupter 13 the operator closes a line switch 23, Fig. 1, thereby moving the arm 40 from position X to position Y. The dial switch 19 is then moved to its first position to de-energize and energize the master relay 34, Fig. 2, once. The relay 34 closes the circuit of the magnet 36 to advance the arm 40 to position A<1> and a time-lag relay 38 is energized to open the contacts 52, 53. The engagement of contact-members 42, 2 completes the circuit of a relay 37 which operates to open the circuit of the operating coil of the relay 38, and the contacts 52, 53 are closed after a predetermined interval. When the contacts 52, 53 are closed a relay 49 is energized over the contacts 43, 3 and the contacts of the master relay 34. The circuit of the closing-coil 32 is energized over the contacts of the relay 49 and the interrupter 13 is closed. The arm 40 is returned to its initial position by the energization of a magnet 55 provided with a time-lag device. While the interrupter 13 is open a circuit is completed through contacts 41, 1, a buzzer 45, auxiliary contact 31 on interrupter and the primary winding of a transformer 47, the secondary of which is connected across the circuit 18 thereby producing a high tone in the telephone 24. When the interrupter is closed the circuit through a buzzer 45 is opened and a circuit through a buzzer 46 is closed through an auxiliary contact 30. To open the interrupter 13 two impulses are transmitted by means of the switch 19 when a relay 50 is closed to energize a tripping magnet 33. To ascertain only the position of the interrupter three impulses are transmitted to bring the contact arm 40 opposite the contact group C<1>. By dialing the numbers 4 or 5 or 6 the interrupter 14 is either closed or opened or its position indicated. If any section becomes faulty the operator may close interrupters 16 and 17 and open the interrupter 14 to determine between which interrupter the fault occurs. If the fault occur on the .section between interrupters 16, 14, the interrupter 13 may be opened to determine whether the fault occurs between interrupters 16, 13 or interrupters 13, 14. A system of harmonic selection or a selective carrier wave system may be employed.