Quick update: POCO went out there and put their testing equipment on the load side of the meters and left it for a couple days. They said it varied only 2 volts.
I went out there today to check on a few things. I only looked at one meter/main the sub panel to it's left and the three sub-panels that are fed on the inside. I did find a neutral that was loose in one of the inside sub-panels. I figured this was it. I then opened all panels and tightened everything. I then checked my voltage at a few outlets. I found that the voltage was high this time (128); a problem the tenant told me about. Infact he said if it wasn't around 100V it was up around 140V.
Still collecting data, I decided to check the meter/main case to the sub-panel case it fed to the left. I got around 30V. I then decided to shut the sub-panel breakers off (all of them) and test the ground to the load side of those breakers. Again, around 30V. Finally, I decided to shut the meter/main off and test it's case to the sub-panel case; around 30V.
The one thing I did notice is there isn't a good bond between the meter/main case and the sub-panel case. They rely on a chase nipple and lock nuts. I know to neutralize the case to case voltage I could put in a bonding jumper, but this doesn't fix the real problem.
I did examine the GEC and it seemed to be in fine shape. The wire went underground so I couldn't see if there were any further problems with it.
I'm open to suggestions.
Thanks
