Patent GB-191328633-A (GB)
Title: Improved Switching Devices for Electric Installations.
IPC: H02J3/04
Filed: 1913-12-11
Granted: 1914-07-23
Abstract: 28,633. Siemens Bros. Dynamo Works, [Siemens Schuckertwerke]. Dec. 11. Switching systems.-The bus-bar connexions of an electric supply system are provided with isolating-switches and some with power switches, and auxiliary leads and isolating-switches are provided by means of which all the connexions are made and broken at the power switches. The isolating and power switches may be interlocked to avoid errors during the switching operations. In the arrangement shown in Fig. 1, the lead m1 is provided with an isolating-switch a1 and a power switch S1 having an overload cut-out winding R1. Leads d1, d2 are provided with isolating-switches a1, a2, while an auxiliary lead band isolating- switches f1, f2 are provided by means of which either of the leads d1, d2 may be disconnected from a bus-bar L through the power switch S1. Modifications are described in which four leads are controlled by one power switch and six leads by two power switches. In the modification shown in Fig. 4, a common power switch S is placed between the auxiliary lead b and the bus-bar L, and may be employed to disconnect either of the leads mI, mII, d1, d2, d3. The switch S is normally closed and may be employed to disconnect a faulty lead by placing in each lead an automatic switch which connects the faulty lead to the lead b and disconnects it from the bus-bar L, the faulty lead being then disconnected by the switch S and its overload coil R. In the modification shown in Fig. 6, the bus-bar L is provided with isolating- switches t1, t2, while the leads mI, mII, provided with power switches SI, SII, are connected by an auxiliary lead b containing an isolating swit.h f and the leads d1, d3 connected by a lead b1 containing an isolating-switch f1. In this arrangement, the power switch SI controls the leads mI, d1, d2 and the switch SII the leads mII, d3, d2. Modifications are described (1) in which four leads, two connected on each side of an isolating-switch in the bus-bar, are controlled by two power switches, an auxiliary lead and isolating-switch, and (2) in which six leads are controlled by two power switches, three isolating-switches in the bus-bar, and two auxiliary leads containing isolating- switches. In the arrangement shown in Fig. 8, two bus-bars f 1, L2 are employed to either of which the leads mI, mII, d1, d2, d3 may be connected through isolating - switches. The leads mI, mII are adapted to be connected by an auxiliary lead b containing a switch f. When either of the leads d1, d2, d has to be switched in or out all the other leads are connected to one bus-bar and the particular lead connected to or disconnected from the other busbar by means of one of the power switches. In the arrangement shown in Fig. 10, the isolating- switches of the main and auxiliary leads are replaced by single change-over switches t1, t2 . . . t5 and the power switches replaced by combined power and change-over switches SI, SII, SIIIÀ In this arrangement, to disconnect the lead d1 by the power switch SI, the switch t1 is placed in position 1 and the power switch SI in position 1. The switch t1 is then placed in position 2 thereby disconnecting the lead d1 from the bus-bar L. The bus bar h is then disconnected by the switch SI, after which the switch t1 is placed in position 3, thereby disconnecting it from the bus-bar h. An electrical interlocking arrangement between the power switch S and isolating-switch t is shown in Fig. 11, in which the switch S is held in one of its operative positions by means of a spring-controlled detent g adapted to be attracted by an electromagnet C when this is sufficiently energized. The movement of the switch t is controlled by two detents z1, z2 on a spling-controlled arm adapted to be attracted against the action of a spring by means of an electro-magnet V. To disconnect the lead d1 by means of the power switch S, the movable contact of this switch is moved to connect the bus-bar h to the lead mI and bus-bar L and is held in this position by the detent g. The magnets C, V are then connected in seties and the detent z1 is moved out of the path of the arm of switch t which is then moved to connect the lead d1 to the bus-bar h ; further movement being prevented by the detent z2. The increased energization of the magnet C then withdraws the detent g and allows the switch S to return to its normal position, thereby disconnecting the bus-bar h and lead d1 and de-energizing the magnet V so that the detent z2 is moved out of the path of the arm of the switch t and allows the arm to disconnect the lead d, from the bus-bar h. In the modified interlocking arrangement shown in Fig. 13, the isolating-switch t is provided with two additional contacts k1, k2 adapted to be bridged by a contact on the arm of the switch t, while the magnet of the switch S is provided with two windings n, n1. To connect the lead d1 to the bus-bar L, the switch t is operated to close the contacts k1, k2; thereby energizing the winding n1 of the magnet to open the switch S. The magnet V is then deenergized and the projection z2 is removed from the path of the switch arm t, which is then moved to position 2 to de-energize the coil n1 when the switch S is closed by the spring g to connect the lead d1 to the bus-bar L. The magnet V is also energized to remove the projection z1 from the path of the arm t, which allows this arm to be moved to its final position.