Air compressor pressure switch.

[modelaratrod]

I've got an air compressor that shuts off @ 175 psi and kicks back on @ 140-145 psi, I would like to adjust the pressure switch so it will kick back on @ 150-155. There are a few adjustment screws in the pressure switch one of which is covered with tamper proof paint gel stuff and the other is not, I turned the one I could 1/2 turn each direction and nothing seamed to change. Anyone changed there psi start back up level? For what it's worth it's a 5 hp 80 gal shultz two stage.

 

[EOC_Jason]

If you do some searching online there is some web page that has pictures of a bunch of different pressure switches and what the two dials do...

There's basically two setups...

First: One dial controls the cut-off pressure, the other controls the cut-in and they act independently of each other.

Second: One dial controls a set pressure and the other controls the cut-in/cut-out difference. Adjusting one dial will have an effect on the other dial. I know it's hard to explain, but I've come across these and it will drive you mad until you realize what is going on.

The best advise I can give is get a piece of paper. Write down exactly how much you are turning each dial and just experiment...

EDIT: Here's a good PDF, check it out: http://www.vikinggroupinc.com/usrelated/general/pressureswitchadjustment.pdf

 

[modelaratrod]

Thanks Jason, that Furnas Model 69 W looks like the one I have. I couldn't find any model # on it.