Compressor Problem

If you switch it back on again after cool down does it gain another 25 psi on top and do the same, or does it labor straight away?

3HP is a fairly substantial unit, is this at home or a shop? Could be an issue with the current draw and cable sizing or breaker getting hot. 3HP @ 230V is a 10 Amp current draw.

Thanks Julian, no it doesn't gain any more it labors right away. It's on a dedicated 20 Amp circuit. The plug to the motor is only 3 feet 12 gauge wire.

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I rechecked the wiring and all seems right.

You are using a double-pole breaker, right? It should have two toggles that are joined together so if one phase trips, both breakers trip in unison.

You do NOT want a 'twin' breaker, that is just two smaller case single pole breakers in a common housing - they are made to save space.

To check, remove the breaker. The two metal tangs that engage the buss bars should NOT be mating to the same bus bar. If they are, you have a twin, not a 2-pole.

Third image in the photo shows the tangs on a two pole.

I imagine this is not your problem, the compressor would surely run very slow if at all, but most folks don't deal with 208/220 breakers very often.

3HP on a 20 amp circuit should be fine.

Larry

Larry, Bingo!! That must be my problem. I have a 20 Amp twin breaker. I will get the right breaker today. Thank you very much.

All fixed and runs like a champ!
Thanks guys

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All fixed and runs like a champ!

Glad to be able to help, from about 3000 miles away..

I just love a happy ending.

Larry

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To check, remove the breaker. The two metal tangs that engage the buss bars should NOT be mating to the same bus bar. If they are, you have a twin, not a 2-pole.

I'm curious. What was the exact problem? If you had used a twin breaker and the metal tangs were on the same bus, then it could not have run at all (same potential).
Will

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If you had used a twin breaker and the metal tangs were on the same bus, then it could not have run at all (same potential).

Yea, I kinda wondered about that, too.

But I just figured the problem was solved and all is now good.

I suspect there were wiring issues other than just the breaker.

Larry

Guy's the original breaker was a single breaker. The motor was only runing on 110V. The new breaker is a twin 2 pole.