meggar test under high vacuum

[rishab1508]

Can anybody suggest that why we should not do meggar test of a motor under high vacuum?

[Grizzly]

Because it screws the motor windings.
Read any of the many previous posts on this forum.
Unless of course you intend to come up with a new way of doing things?
Grizzly

[monkey spanners]

Two reasons, first without the pressure of refrigerant in the compressor there is little to stop the high voltage used in megger testing jumping across windings and connections inside the motor, this can cause tracks similar to old distributor caps and ignition systems in cars, so when you try to run it later on it burns out the motor. Also i expect the resistance values measured would be inaccurate for the same reason causing you to condemn a good motor.

[install monkey]

can anybody answer why you would need to or want to megger a pot under a vac?
Can anybody suggest that why we should not do meggar test of a motor under high vacuum?

[rishab1508]

Thanks for your valuable input..