GB367328A - Safety arrangement for electrical power installations - Google Patents

Abstract

367,328. Protective cutout arrangements. SIEMENS-SCHUCKERTWERKE AKT.-GES., Siemensstadt, Berlin. Aug. 13, 1930, No. 24253. Convention date, Aug. 30, 1929. Void [Published under Sect. 91 of the Acts]. [Class 38 (v).] In the protection of parallelconnected generators I, II, III supplying bus-bars 12 feeding distribution circuits of varied importance (for example, the installation on board a ship) on the operation of delay-action overload relays 4 or instantaneouslyacting reverse current relays 7 in any one of the supply leads from the generators, the feeder circuits are cut out one after the other beginning with the least important until only so much load is left on the sound generators as may be adequately dealt with. The sequential operation is effected by electrically interlocking the tripping relays 17 of the feeder circuits by means of switches 19 each one of which on operation prepares the tripping circuit of the next. Alternatively, the feeder tripping relays may be time-graded and operate in predetermined succession until the load is adequately reduced. The reverse-current relays in the supply conductors cause instantaneous operation of a relay 15 which cuts out all the feeders except that supplying the scavenging air blower for the Diesel engines and, in this case, the load is reduced by short-circuiting shuntregulating stages of the motor. A similar action is produced on substantial drop of voltage by the voltage relay 22. The feeder circuitbreakers may be tripped at will by manual operation of the switch 23. In a modification, Fig. 2 (not shown), when a fault develops in one of the generators the parallel connection between the two generators is interrupted (together with the supply to an unimportant part of the load) and with the supply coming from one generator only the feeders on that generator are successively cut out until the load is adequately reduce .