Originally Posted by
Derlyn
Hi All
A bit of feedback.
Meggered the motor. Result infinity.
Connected the fan in my workshop and tested.
Turned it on and off a couple of times ..... no problem.
Left it running for an hour. When I turned it off, the earth leakage tripped.
While the motor was still warm, I meggered it again and found the reading to be lower than when the motor was cold. 1,5 megs.
The insulation resistance is reducing with an increase in temperature.
I am aware that the earth leakage should only start tripping when the insulation resistance is approx 8k or lower, but I suppose the reduction in insulation resistance combined with the arc from the switch does something that causes enough current to earth to trip the earth leakage.
I still don't fully understand the theory behind it, but I now know that it's the fan that's faulty.
Derek
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