N-G multiple bonds testing

[living2learn]

I found on one of my jobs multiple neutral to ground bonds. They have since been fixed except we need to verify this. The challenge comes from not being able to turn off the substation to test the impedance between N-G. The substation feeds one lighting panel 4w+g and a few MCC's that are all 3w+g. Does anybody see an issue with turning off power to the lighting panel and removing the neutral while the substation continues to supply 480V 3w+g power? We will then test to ensure there is not another bonds. FYI The bonds where in the generators fed by 3 pole ATS's

 

[waross]

Put a current source between the neutral and the ground bus. Check the current from the source and then check and verify that the same current is flowing through your one neutral to ground connection.

Bill
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"Why not the best?"
Jimmy Carter