Compression (husky 120v) starts only when empty.

by Chad
(Corvallis, Oregon, USA)

about 90% of the time the compression will only start when empty. maybe 10% of the time it runs as normal.

When it malfunctions this is what I have been able to note:

If there is more than 2-3 PSI in the tank it will attempt to roll over a few times. It will act as if it wants to start, but after 2-3 attempts (it actually does turn over maybe once or twice but at a much reduce speed, stops, then tries again) the safety breaker built in engages and has to be reset.

Emptying the tank causes it to function, but when the pressure is reduced to ~80psi when the compressor is supposed to turn back it it does it again and I have to empty the tank.

Using a DMM I measure 120v when the compressor is not running, and 169V when the compressor is running (not sure what is normal) across the starting (or running) capacitor (it only has one capacitor, not sure what it is).

I have removed the capacitor in the past and charged it to 12v and -12v with success, I now have a larger DC power supply to test it but can still only test it to 36v if necessary.

__________________
Bill says...

Chad, drain the tank to zero PSI. Plug the compressor in and start it. Let it run up to normal cut out pressure. As it nears that level, get close and personal with the unloader valve.

When the compressor reaches cut out pressure and stops, does the unloader valve work?

Post your response as a comment here, please.

Cheers,

Bill