Sanborn 500A60 compressor will not turn off?

by Tony Lucero
(Herald,Ca , USA)

I have a Sanborn air compressor 500A60 model that will not turn off when the press reaches 130lbs.


The safety will release the pressure like it is designed.

I have replaced the pressure switch and check value and still does not work. Any suggestions?

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Dec 11, 2018
Sanborn 500A60 won't turn off?
by: Doug in s.d.ca.

Just to be clear, if you turn it on and do nothing else, it eventually blows the safety valve and keeps running?

Can you turn it off manually with the pressure switch?

Dec 10, 2018
500A60 won't turn off
by: Bill

Are you certain that the new pressure switch has the same cut in and cut out settings as the old? I believe this compressor has a cut out of 130 PSI.

If power is still flowing to the compressor motor and the tank pressure reaches and then bypasses the correct cut out setting pressure on the pressure switch, then it pretty much has to be the pressure switch not reacting to the tank pressure.

Maybe the points have become welded closed and the switch cannot open to cut power, perhaps the wiring points inside the switch were different than the old, and you have hot power running through the switch regardless of the pressure, I can't be sure. Yet I'm pretty sure that the issue is with the pressure switch.

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