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roberts311
May 15, 2018, 05:29 AM
A bit of an oddball item to test, but this conversation came up recently. Obvious valid tests, in my mind, for Circuit Breaker Ground Cart testing would be to DLRO each phases of the bus to ground. Possibly Primary Injection. One of our colleagues suggested Hi-potting. What is everyone's take?
SecondGen
May 15, 2018, 12:41 PM
A bit of an oddball item to test, but this conversation came up recently. Obvious valid tests, in my mind, for Circuit Breaker Ground Cart testing would be to DLRO each phases of the bus to ground. Possibly Primary Injection. One of our colleagues suggested Hi-potting. What is everyone's take?

Are you referring to a MV Ground & Test Device? If so, we usually do a DLRO in both positions, megger and hipot just like we would a medium voltage breaker. Not sure what primary injection would do in this case...
ElectricalTestTech
May 16, 2018, 02:06 AM
Are you referring to a MV Ground & Test Device? If so, we usually do a DLRO in both positions, megger and hipot just like we would a medium voltage breaker. Not sure what primary injection would do in this case...

I am thinking along the same lines as you SecondGen. A medium voltage ground and test device is the only thing that comes to my mind.

DLRO - insulation resistance - hipot