Odd Problem - Any Ideas?

hedkrashd

I'll try to make this as short as possible.

I've had the same setup in my garage for 8 years.
50amp 240v to a sub panel in the garage. Several 20amp 120v circuits running off of it.

My compressor just "quit" working about 2 weeks ago. It was cheap and 8 years old, so I figured it just gave up. Bought a new compressor, plugged it in and the same thing happened, motor spun very slowly, wasn't working. Eventually the breaker kicked off.

I started up my generator, plugged the compressor in, and it ran like a champ. Obviously something wrong with the electric.

Thinking there might be a short somewhere in the garage, I kicked all the breakers off except one that was dedicated to a single plug. No luck.

I tried a plug off the other 120v circuit, same problem.

I pulled the cover off the panel and tested the voltage on each side and they were 120v. I tested the 240v connections, and they were correct. I made sure all connections were tight.

All the lights, garage door opener, forced air heater, etc still work without issue.

I'm thinking maybe there's a ground problem, but not really sure how I'd go about testing that.

Any other ideas? Thoughts?

Thanks

hedkrashd

Ok - so obviously I posted in the wrong thread - I'm correcting that - but how do I delete this post?

Ron6519

I'm sure a moderator will come along and move to electrical.
I had the same issue with my compressor when it was on a tandem breaker. Once I put it on a single 1" breaker, the issue was no more.
Ron

AllanJ

Have you measured the voltage at the compressor junction box or connection box during the time the compressor was trying to turn?

Check all the connections in the breaker box for tightness. Include all the set screws where the neutral and ground wires are attached. You should have an experienced person check the big lugs where the fat wires from the meter are attached.

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