Patent GB-361309-A (GB)
Title: An arrangement for showing at a glance the consequences of switching operations in power distribution installations
IPC: H02J13/00
Filed: 1930-05-09
Abstract: 361,309. Distant-control systems and apparatus. AKT.-GES. BROWN, BOVERI, ET CIE, Baden, Switzerland. May 9, 1930, No. 14295. Convention date, June 3, 1929. [Class 40 (i).] A generator 1 feeds a bus-bar 5 of a distant station over two switches 3, 4 adapted for remote control by manual switches 3a, 4a in known manner, the positions I, II of those switches corresponding to the on and off positions, respectively, of the main switches 3, 4. If, with switch 4 open, the switch 3 is opened, the substation 5 is disconnected, so the switches 3a, 4a have intermediate testing positions III whereby, on moving switch 3a from position I to position II to open the switch 3, an indicating lamp 3b is lit from the battery 6, but if the switch 4 is closed (so that opening of switch 3 will not disconnect the substation 5) the switch 4a will be in position I whereby the lamp 3b is shorted and does not light. The lamp 3b is used therefore to test the result of an intended switching operation, i.e. whether it will disconnect, or connect up two lines which might not be in synchronism, or whether a circuit was about to be opened at an isolating switch incapable of opening that circuit. Where the switches, say 3, 4, are adapted for automatic release on overload, so that the corresponding switches 3a, 4a are still at the closed position I after release of the switches 3, 4, the system shown in Fig. 2 is employed to supplement that of Fig. 1. The switch 3 on opening closes at 3g, 3h in position II the circuit of a lamp 3b over contacts 3d, 3e of the control switch 3a still in position I, the lamp 3b being shorted by contacts 3i of switch 3 while the latter is closed. If, however, the switch 4 is still closed, the lamp 3b is shorted at the closed contact 4f of the corresponding control switch 4a. The lamp 3b will only light therefore when automatic release causes complete disconnection and until 3a has been moved to position II. When the switch 3a is moved to testing position III, whatever the position of switch 3, the source 6 will be connected to the analogous switching arrangement as in Fig. 1. Developments of the invention are described for indicating (1) which parts of an installation will be disconnected by a switching operation, Fig. 3 (not shown), (2) whether two parts of a system to be connected have independent sources of voltage, Fig. 4 (not shown), (3) whether a source at the distant end of a long line (which cannot conveniently be provided with an indicating system) will remain alive or not when sources of current at the near station are switched off, Fig. 5 (not shown), and (4) by means of voltage relays, Fig. 6 (not shown). The electrical indicating system is also applicable to the remote control of, for instance, steam distribution networks wherein valves take the place of main switches. The Specification as open to inspection under Sect. 91 (3) (a) describes also a locking means for preventing a control operation in certain conditions. This subject-matter does not appear in the Specification as accepted.