scenario: A barn is fed from the house main panel with 60 amp dp breaker. There is a Sub in the barn. homeowner said breaker in barn was tripping for air compressor. They had their son check it, he tried to wire the 240v motor from from one leg. After smelling horse s$#t for an hour I finally found he wired it from one leg in panel.
Compressor was wired correctly, everything ran fine, no trips. I watched it for a while on amp probe. I was there most of the day installing fans etc etc. compresor worked fine.
I get called back a week later, compressor was not running. I checked voltage at main, 240 across, 120 to ground. I checked at sub panel , I had 240 to ground and 0 on other leg, 175 across??
I pulled all breakers from panel and checked:everything was fine:120 to ground, 240 across. When I replace the breakers one by one untill i get to the lighting circuit (by the way its a new panel, new breakers)I get 175 on one leg and like 30 on the other. Everything in the barn reads like this. it is still reading normal at the main when it does this. what is going on?? I have isolated all circuits and metered them for shorts, everything looks fine.
I am going back in the morning to change out the 40 year old ceramic light fixtures.
any pointers would be greatly appreciated.
I will check in the morning before I go to the site,
