How to find earthfault location in long cable layed
underground or outside.
Answer Posted / rax
transverse nature of waves is utilised to find the location of fault.when a high dc voltage is superimposed on a signal it becomes a wave. now this wave is given a velocity of 67.5meters/microseconds for 11kv cable and 80 meters/microseconds for 33 kv cables. at the open end the voltage is doubled and the wave is reflected .the time taken by this wave to reach the source is noted and the distance is calculated.
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