Need a pressure switch for a big ol' compressor

[Blaze]

Can anyone help me out here? Not sure which one I'm needing. I've replaced the one on my house shop once before, but it was easy to match up the number, etc. This one is an ancient huge compressor I got off of a friend of mine. The pressure switch was broken and missing parts and rusted to shreds. I have no idea how to match it up.

The compressor is a really old Wayne with an 80gal tank, 2-stage, 220V single phase, 5hp. The existing switch looks like the kind of switch that is on a well pump system for water, with I believe a 1/2" NPT male fitting on the bottom.

Anyone steer me in the right direction?

 

[Ron]

There will be different model numbers depending on the set point you want.
Something like this would work

Square D (Schneider Electric) 9013FHG12J52 Compressor Pressure Switch with Increasing Pressure 70-150psig | Graybar Store

 

[Ron]

This is a better link:
air compressor pressure switch Water and Air Pressure Switches - Pressure, Vacuum, and Vibration Switches - Grainger Industrial Supply

 

[Ron]

The determining factors on which you need is:
1 - Port size
2- Desired Spread differential
3- Tank rating

 

[Blaze]

Tank is rated for 175#. 30# spread should be fine.

Thanks for the link, that is exactly what I need. Kind of had a thought in my head of what I needed, but didn't want to just go by a hunch.

 

[catfishblues]

I've actually had great luck with the cheapie Chinese ones off Amazon. I've used two different models. One, the cheaper, is currently happily controlling a 6hp Baldor motor on my 80 gallon unit. The other, slightly nicer with a lever, is running the contactor on a 3-phase compressor at my old shop. It doesn't see much load. Both can be had for under $20, and have manual on/off capabilities and will run the unloader, too. Port size can be matched using bungs to reduce the 1/2" to 1/4" npt.

 

[LBZ_Duramax]

I would want to inspect the inside of that tank well before running to pressure if it has been sitting a while. Would be bad to have it blowout because rust ate through the bottom.