compressor build to about 150PSI and then slows til belt starts slipping

by Mark J
(Griffin,Ga)

I have a 5 hp ACS brand compressor.

It is for hobby use so it is not used that much.

It is outside but under shelter.It is about 3 yrs old.\

It will run perfectly until it reaches near 150PSI (it shuts off around 175psi)Once it nears 150 you can hear it get slower and slower as the pressure rises.Then it will keep slowly running til the belts start to slip.What could cause this.I inpected the check valve and it looks ok.Any ideas?
Mark

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Bill says...

Mark, your belt is slipping because the load exceeds the friction between the belt and the sheave.

If the belt is slipping on the sheave, something is loading the sheave to make that happen.

As the pump works harder to pump more into the tank it gets hotter, and if there is a low oil issue, that might account for this.

Or, as it gets hotter, inside the pump the parts have worn and the piston is binding a bit.

Pretty hard to diagnose from afar.

Sounds like your motor is fine, or the belt wouldn't slip, the motor would just stop.

If the check valve is fine then I'm guessing it's a mechanical issue in the pump.

Cheers,

Bill