Craftsman 6HP 33 gal unit compressor blows Breaker

by Dave
(ohio usa)

Craftsman 6HP 33 gal unit compressor blows breaker under load.

I can remove the drain plug from the bottom of the compressor tank and the compressor motor will run fine no problems blowing air out the bottom of the tank. shut down and re-install the drain plug and the compressor runs for a couple seconds then blows the breaker. any ideas whats causing this issue.

_____________________
Bill says...

Dave, it sounds as though your motor is pulling too many amps under load.

Load is what happens when the pressure in the tank begins to build, and the motor has to work harder to pump air into the tank against the building back pressure. By opening the drain valve, you are venting the pressure, and hence to back pressure or increasing load on the motor.

Make sure you have clean power, and if so, then I'd look first to the run capacitor or the motor itself as the problem.

I'm still trying to find an easy way to test capacitors at home, no luck so far.

Maybe get the capacitors and motor tested at an electric motor rebuild shop?

Cheers,

Bill