Compressor starts but motors stalls before 30lbs

by James
(Finch Ontario Canada)

I just bought new compressor had new wiring run and hooked up start compressor and runs fine until about 25lbs then motor lugs then stalls. Thought it needed bigger breaker bought 30amp but still does the same motor clicks.

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Bill says...

If you are saying that the compressor starts when there is zero pressure in the tank, that suggests that it has never reached cut-out pressure, which is likely in the area of 125 PSI or so.

So, from new, the compressor never got past 25 PSI before lugging and stalling?

I'd look first to my pressure switch, making sure that you can toggle the points by flipping the handle a few times and see if that helps.

If the switch is working fine, and you have oil in the compressor (if it's oil lubed) then I'm afraid you may have a serious problem with the motor or the compressor head.

The motor is lugging (assuming you are getting sufficient electricity flow to it - that's why I suggest you check the pressure switch ) because the load is increasing to the point where the motor cannot overcome it.

Also, with the tank empty, and the power off, pull the air line where it goes into the tank to be sure that the check valve is operating freely.

See the check valve page on this website for more info.

Cheers,

Bill