Relay Anomaly

When the 11kv conductor snapped, which part (energized/deenergized) was still connected to the earth fault relay? I suspect this would be really important.

I too might be astonished by this, but astronised? Did you actually see stars?

thankx a lot 4 ur pecious comment......

brother it was actually energised (sending) part wic was in connection with the ground......

so according 2 the logic the relay must had to trip as the fault persist for nearly an hour ..............

can u suggest me some possible reasons 4 this please....

thankz sir..........

Read the above responses again, your answer is there.

The AMOUNT of earth fault current flow that occurred was insufficient to trigger the relay. It isn't likely to be any more complicated than that. Just because the cable was touching the ground does not automatically mean massive amounts of current will flow. Could have been high resistance, the ground may have been dry, all manner of issues that prevented the current from flowing in significant amounts.

That's why live conductors lying on the ground should never be touched. YOU might be the catalyst that facilitates current flow, but by the time the relay trips, you are a charred cinder.

The snapped conduct mustn't have made a good a good connection to earth. Most OH lines have a high earth fault tolerance otherwise they would trip every time it rains.

I've seen a 11KV line snap and the conductor was lay on dry ground quite happily setting fire to the grass, the supply didn't trip un till it was done manually.

The reason is that, when the conductor broke, no earth fault was created.

Probably the earth fault relay was waiting for a currious squirrel to come by to see what that line was laying on the ground...