How do i adjust the turn on and turn off pressure of my air compressor?

by leaman
(seattle WA)

Bought the tank used. Tank rated for 120 p.s.i.
I think the prior owner of the compressor messed with the settings. There appears to be / are two adjusting screws.

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Bill answers...

Hello Leaman, nice to hear from Seattle.

It sounds to me like you've already found the device that turns on your compressor at the cut-in pressure point, and shuts it off again when it reaches the cut-out pressure, and that device is the pressure switch.

Some are meant to be adjusted. Others are not.

You say the previous owner "messed with the settings" yet you don't indicate what the present settings are.

You are correct, if your pressure switch has two nuts on a threaded rod with springs below them, those are the adjusting nuts.

Make sure you pull the plug first.

Look inside the cover to see if there are any instructions printed there.

You should have noted also at what pressure point your compressor cuts-in and cuts-out now. Drain air from the compressor until the pressure setting is below the cut-in point.

Turn one of the nuts tighter (this should increase the setting) 1 turn. Plug the compressor back in, and see what the change has accomplished, and which setting changed. (The cut-in or cut-out level)

Mark on the pressure switch cover which nut is which, and continue adjusting to suit.

Beware that you do not set the cut-out pressure too high. You could have disastrous results.

Cheers,

Bill