Patent GB-279556-A (GB)
Title: Improvements in or relating to electrical remote control systems
IPC: H02J13/00
Filed: 1926-07-29
Abstract: 279,556. Reyrolle & Co., Ltd., A., and Leeson, B. H. July 29, 1926. Selective distant control systems; order apparatus; positively moved electromagnetic indicators.-In an electric distant control system for selectively controlling a number of apparatus units such as circuit breakers, selection is effected by a rotary contact drum operated stepby-step by hand actuated means, such as a press button switch. In any selecting position of the drums, circuits are prepared for giving an indication of the condition of the units and for operating the unit. As shown, selection of one or other of the circuit breakers N, O is effected by a drum switch J (shown diagrammatically) operated step by step by a solenoid L, which is connected in circuit with the lines A, A<2> and is controlled by a push switch F located at the control station. A solenoid O also connected in the line circuit simultaneously operates a step-bystep indicator B' to indicate the selected unit. The circuit over the lines A, A<2> is normally closed, but the current is insufficient to cause operation of the solenoids L, O. Actuation of the push F however cuts out resistance and thereby facilitates control. A two position indicator G<4> for signalling the condition of the selected unit is controlled by a solenoid G, which remains inoperative during selection since the current strength is insufficientto cause operation. Each circuit breaker is associated with three contacts, such as P', Q<1>, R<1>, on the drum switch J, which contacts are adapted to prepare the circuits of the closing and tripping coils e.g. N<4>, N<3>, and a circuit which effects the control of the indicating device G<4>. To select a circuit breaker. the drum switch J is stepped forward by the repeated operations of the push switch F until the circuits of the circuit breaker are prepared by the appropriate contacts P<1>, Q<1>, R'. If the circuit breaker is in its " open " position a resistance, such as N<2>, is thrown in parallel with the solenoid L to increase the line current sufficiently to cause the indicator G<4> to operate and display the word " out." If however, the breaker is " closed " the indicator remains inoperative and displays the word " normal." To operate the selected circuit breaker the push switch H is depressed to operate a solenoid S over the line wires A<1>, A<2> and thereby energize one or other of the coils N<3>, N<4>, depending upon the position of the circuit breaker, over the contacts S<1>, L<3>. If it is desired to " open " the circuit breaker the push F must be maintained depressed in order to prepare the circuit of the tripping coil at the contact L<3>. When the circuit breaker is operated the indicating circuit is opened or closed according to the nature of the operation at the contact N<1> in order to cause operation of the indicator G'. If. when the drum switch is in its normal position, a circuit breaker trips automatically, a contact, such as N<6>, energizes a relay T which locks up over the contacts T<2> and switches a resistance across the solenoid L to effect the operation of the indicator G<4>. In the event of a circuit breaker opening automatically during selection, a relay U is operated over contacts P to energize the relay T which causes the operation of the indicator G<4> when the selector switch J is restored to normal. In order to ensure synchronous operation of the selector switch J and indicator drum B<1>, contacts L<2>, D<2> shortcircuit portions of the series resistances L<1>, D<1> to increase the working current upon each operation of the solenoids L, O. Either direct or alternating current may be used in the line wires and one of the wires may be eliminated by employing direct current for controlling the selector switch and superimposing alternating current for operating the circuit breakers upon the same circuit and vice versa. The push switches F, H may be suitably interlocked to prevent false operation and a recorder may be operated simultaneously with the indicators B<1>, G' to give a complete record of the changes of condition of all the circuit breakers. The Provisional Specification states that the circuit breakers may be arranged in groups, each group being independently controlled or provided with selectors brought into action successively. Furthermore, two dimensional selectors may be used, the selectors may be reset to normal at any stage of a selecting operation and may be reversible. This Specification also describes means for ensuring the correct operation of the selecting equipment and states that two dimensional selectors may be employed.