PI testing on 13.8 kv motors

[gronk2003]

Is there any value in doing a 5000 volt PI test on a 13.8 kv motor. Even if the readings are trended?

 

[electricpete]

I think if you are planning on trending the readings, the PI is more valuable than the 1 minute reading.

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[gronk2003]

My question was more along the lines of the value of voltage, 5000 volts 0n a 13.8kv motor.

 

[electricpete]

IEEE 95-2000 gives the following guidelines for test voltages:

VLL(vac) Test Voltage (vdc)
==== =========
<1000 500
1000-2500 500-1000
2501-5000 1000-2500
5001-12000 2500-5000
>12000 5000-10000

5kvdc test of 13.2kv machine is consistent with these guidelines. We use 10kv test at our plant. I don't think using 5kv would be a big problem (there may be slight tip-up if contamination is present). Most important thing for trending is to use the same voltage each time.

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[aolalde]

gronk2003:

See Thread &quot; Generator PI Value Problem&quot; 01/10/04 by edison123.

 

[jbartos]

Suggestion: 5000VDC is sufficiently high to reveal insulation DC resistance. It is also sufficiently low for 13.8kV not to cause any damages to insulation. Contact the IEEE 95-2000 working group to find out all details behind the selected voltage.

http://www.ieee.org