Faulty line section indicating system for power distribution grids - has relays responding to short cct. currents and controlling alarm lights

摘要

The faulty line section indicating system for power distribution grids has a line relay inductively coupled to each section of the line with its own substation and responding to short circuit currents. The grid is supplied at both ends over two circuit breakers which are linked by a control line. Each substation and line relay are connected to an evaluator. When a short circuit occurs the second breaker operates and a control signal is passed to the evaluators. A second control signal is passed from the opposite end of the line to the evaluator monitoring the shorted section. A first relay connected to this evaluator becomes activated. The second circuit breaker opens after a delay, e.g. 300 msec., and the first relay is deactuated. This deactuation causes a second relay to oscillate and light up a blinker light indicating the faulty line section.