Campbell Hausfeld compressor blows fuse on restart

by Pawel
(Springfield, MA)

Campbell Hausfeld parts list

Campbell Hausfeld parts list

I have an older Campbell Hausfeld compressor with a Curtis challenge air ES-20 pump along with a 5hp motor on it.

It recently started having a problem restarting.

I did some research and everyone was saying Unloader valve so I got a new pressure switch/Unloader valve with same ratings as what was on the compressor and it still does it.

If there’s pressure in tank the motor is working very hard and trips the breaker.

I have verified that the Unloader valve works even have held the manual pressure release open when restarting compressor and still the same.

I just looked up challenge air es-20 breakdown and they show a manual Unloader valve on top of the intake valve in each head.

Any ideas on how to test or repair those?

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Nov 12, 2018
Campbell Hausfeld hard start
by: Doug in

Ordinarily, the motor starts in just a few revs, and gets to power. Sounds like yours never gets to power speed.

That is usually either a bad start capacitor, or a leaky check valve.

With the tank empty, it starts OK, yes? If so, does it stop at cutoff pressure, and hold pressure after that? The check valve is supposed to close and the unloader open when it shuts off. If it doesn't hold pressure at that point, your unloader is working, but the check valve isn't. You may be able to hear it leaking at the pressure switch.

Unless you have a non-typical setup with that pump.

Let us know...

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