125VDC ground fault inspection & correction

[rickypegasus]

Recently a representative from a DC System Grounding Inspection equipment manufacturer conducted substation 125VDC ground fault inspection and found measured parameters.

At 125VDC Bus
Positive to negative terminal = 137VDC
positive to ground measures 124VDC
negative to ground measures 13VDC

He then measure one at a time all the branch circuit connected to the 125VDC bus using a DC System Grounding Inspection Equipment and yielded a very high resistance that passed its acceptable/standard value. Hence, he declared that the Substation 125VDC system is free from any positive and negative ground. My concern is, how about the measured positive & negative to ground voltages? Why they are not balanced? Thanks much

 

[SG-1]

I have seen these type of readings before & tracked them back to multible relay power supplies. I have no idea why they are not more balenced.

 

[dbuckley]

I suspect that the voltages are as a result of leakage and the use of a high resistance meter. A lower resistance voltmeter would probably show considerably lower voltages all round.

 

[brian john]

Have you checked your batteries?

Cleaned all the jars?