How to adjust the compressor pressure switch down

by Terryl Cozart
(Tupelo, MS)

I want to adjust the pressure switch down.

I have a Dewalt D55168, 200 PSI 1.8 HP 15 Gallon tank I picked up used the other day. Everything seems to run just fine except it hasn’t cut off on it’s own. I got chicken and cut it off manually. It has reached 200PSI, but it won’t cut off. This thing scares me a little. I would like to cut the pressure down to 175 or so. This seems a little more manageable to me, I just don’t know how or if you can. Any help you can give me would be greatly appreciated.

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Hello Terryl, very nice to hear from Tupelo. Thank you for visiting this site and for writing in.

I suspect that your pressure switch has failed on the high pressure cut-out setting.

Yes, you can adjust the cut-in and cut-out pressure level yourself, but I think that with your switch you will be trying to adjust it in vain.

You are quite correct to be intimidated by the compressor. I don’t know of many smaller that exceed, say, 175 PSI at the high end and this one is rated for 200 PSI.

Do yourself a favor too, and once the pressure gets up to 170 PSI or so, manually toggle the PRV by pulling on the ring to make sure that it’s free. In the event that the pressure in your tank reaches the PRV threshold, it will open and vent the air to prevent pressure rupture. Manually toggling the PRV open and closed will satisfy you that it will actually work when you need it.

Watch the pressure gauge when you close the PRV and let it get to 210 PSI. Doesn’t shut off still?

Change your pressure switch. I think that’s your compressor problem.

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Thanks
by: Terryl

Thanks Bill,
I appreciate the response. You said just what I was thinking. Nice to be backed up.