Electrician type people - shop power out and being weird

Blaze

Blaze

The Jeeper Reaper
Joined
Aug 9, 2005
Location
Wake Forest, NC
We had a big storm here last night and this morning I woke up and looked outside and the power was out in my shop. It has a 200 amp service, two big feeders down to the shop. The breaker at the house is on and fine, the main breaker down at the shop is on and fine. The only way that I can get the lights to come on is to turn on the air compressor. BUT there isn't enough power to run the air compressor, it just hums. I had the 220V breaker for the compressor turned off normally, so that wasn't even on last night. It is too dark to see anything down there right now, but any ideas WTF that could be? It is really bizarre, I've never seen anything like it.

So like, I turn the breaker on, nothing. Turn the safety disconnect on, nothing. Then turn the power switch on the actual compressor, lights come on.
 
Blaze said:
We had a big storm here last night and this morning I woke up and looked outside and the power was out in my shop. It has a 200 amp service, two big feeders down to the shop. The breaker at the house is on and fine, the main breaker down at the shop is on and fine. The only way that I can get the lights to come on is to turn on the air compressor. BUT there isn't enough power to run the air compressor, it just hums. I had the 220V breaker for the compressor turned off normally, so that wasn't even on last night. It is too dark to see anything down there right now, but any ideas WTF that could be? It is really bizarre, I've never seen anything like it.

So like, I turn the breaker on, nothing. Turn the safety disconnect on, nothing. Then turn the power switch on the actual compressor, lights come on.
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Only thing I can guess is that you've lost a leg. The leg you lost is the one that the lights are on and when you turn the compressor switch, there is enough backfeed from the good leg through the motor to run the lights. You'll burn you comp motor up doing this long though!
 
Yes, lost one leg
 
I'll third the lost leg. Happened at my house no less than 4 times when the underground burned through. Power co stopped fixing the 40yo wires and buried new after the last time.
 
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Yeah, definitely lost a leg. I was running out to take my kids to school when I posted this before I got a chance to really diagnose. My first thought was that, but the compressor thing threw me off. Wasn't thinking of the backfeed though. I put a meter on it, lost a leg between the house and the shop. I have a couple of splices on the feeders that have been good for a while, but we got a TON of rain last night and the ground is super saturated and pretty sure one of those splices is grounding out.
 
Pegleg for sure. Happened to my neighbor. Headscratching ensued. Confirmed by power company.
 
Blaze said:
Anyone here have a ground fault locator by any chance? I don't mind paying. Found a guy who said $400 and I'll poke a ton of holes in the ground before I pay $400. :lol:
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Check your house breaker. If you were going to ground it should be tripping.
 
Was the cable run through conduit? I second what Shawn said, just bury new line, little extra now, but will cut back on future issues and you'll know it was done right. Doesn't have to be super deep unless it has some heavier weighted traffic on it.
 
awheelterd said:
Check your house breaker. If you were going to ground it should be tripping.
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Forgot about this, now that you've jogged my memory, had that happen to my breaker for my well. Didn't trip. When I pulled it to replace it, the breaker fell into pieces. Was kinda scary, all I could think was, this was a fire waiting to happen.
 
Yeah, thinking about it now it definitely should be tripping. I'll replace the breaker when I do everything.

I figured out where the break is, too. There was a spot where we were digging around a stump and we nicked the water line. The feeders didn't look to be hit and visually looked ok. I ran a metal rod down by the three spots I know there could be issues and measured the voltage. 0 VAC on the first two, 1 VAC on the third so definitely some electricity bleeding to ground there.
 
Well, my metal rod method worked like a charm. First hole I dug I hit right on the damaged wire. Spliced it and I'm back in business.

Fuck running 150ft of feeder wires with prices right now.
 
Futbalfantic said:
Is there a way to splice that, that is NEC compliant?
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Not sure if it is NEC compliant, but I bought some feeder and underground direct bury splices from my buddy who works at one of the big electrical supply places in the area.
 
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