Compressor blows breaker at 75 psi

by Dave

I have a Campbell hausfeld 26 gallon compressor and the pump seized due to no oil. (My bad)

I found a replacement pump made by Campbell but the cfm was rated at 8.6 and 10.2 cfm where my original was rated for 5.7 and 6.4 com.

It was a direct fit so no new plumbing just had to use old flywheel.

It keeps blowing breaker at 75 psi now ( starts to runs slowly just before it pops).

If I run it with belt off or tube unhooked from pump to check valve it runs and runs with ease.

Only blows under load. Had the motor/capacitors checked and they were good.

There's no extension cord being used.

Read I might have to reduce motor pulley size due to the cfm difference. Make any sense? Help! Thanks

Comments for Compressor blows breaker at 75 psi

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Feb 10, 2017
blows breaker
by: Doug in

Ah so...

Glad you figured it out - so are you modifying or replacing the belt guard?

Feb 09, 2017
Compressor blows at 75 psi
by: Anonymousdave

Hi, everything's working now. Thank you for the help. Found out that the new pump I got came with a different sized pulley (bigger) which if I want to reuse the protective shroud I could not use that pulley so I used the smaller pulley off my old pump. Put new pulley back on new pump and viola. It got up to full pressure but would stil pop breaker when the pressure switch would shut off. Bought a new pressure switch unloader assembly and it's all good now. Thanks again.

Feb 01, 2017
More current
by: Doug in

I just re-read your last.

Are you trying to run that on 120V?

Won't work. You have the rough equivalent of a 1 HP motor at that voltage.

If you can't get that voltage to it, then you'll have rewire it (not likely possible, but maybe) or yes, buy a new motor. 3 HP will do.

Feb 01, 2017
5HP motor
by: Doug in

No, you have plenty of power according to the specs, which say "Do not exceed 1140 RPM at 125 psig or damage may occur to the pump and the warranty will be void"

All you have to do is get the right pulley set. Most likely, your current setup is driving it at twice that.

So, figure it out, or get your motor RPM's and such together as asked, and we'll see what you can do.

Jan 31, 2017
by: Doug in

What Bill said, and yes, it's likely the motor was minimal relative to the old pump, so you won't be able to run the new one with the same pulleys.

You'll need some combination of pulleys to make the pump run at perhaps 3/4 to 1/2 the speed it's running now, or replace the motor.

We can help with that, if needed, but need all the specs you can get on the pump and motor RPMs and HP ratings as well as the sizes of pulleys you have on hand.

Jan 30, 2017
Compressor blows breaker at 75psi
by: Dave

I bought a vt2030 pump and some sites are saying 10.2 cfm and can be run with a 3-5.5 hp motor. Mine is a 5hp/15A motor. Completely baffled.

Can I assume my motor can be upgraded internally to higher amperage or am I looking at a whole new motor?

Does an unloader valve make any sense?


Jan 30, 2017
Campbell Hausfeld blows breaker
by: Bill

The use of a larger pump suggest to me that the motor now has insufficient HP to run it.

What is the HP of the existing motor?

Maybe look for compressors with a similar capacity as the new pump on line, and see what the HP of their motors are.

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