Air Compressor 12 volt pressure switch

[Iplayfarmer]

At some point I'd like to make an engine driven air compressor. How are engine driven compressors pressure regulated?

I'd probably drive the compressor with an electric PTO clutch. I figured that I could use a 12 volt pressure switch that would turn the clutch on when the pressure drops below a set point and then turns it off when the pressure builds sufficiently. Problem is I'm not finding a lot of 12 volt pressure switches.

Is there some other way that the engine driven compressors regulate their pressure?

Could I just use a 120 volt pressure switch?

[barneyrb]

This switch Configuration Results is just a electro-mech that won't care what voltage it gets.

[tommu56]

they continue to run compressor and have and unloader in the discharge line or

like granger #4TK14 it is the control I used to change my electric generator to gas to build my cabin (off grid) with a 8 hp gas engine

On the big construction compressors they have a control that holds the intake valve open exhaust valve is a check valve. and the air goes in and out intake valve and dosen't compress.


tommu

[DieselPower]

Wired properly you can use most any electromechanical pressure switch with the correct pressure setting. Just don't run the main power to the compressor through the switch, run it through a relay. Not all pressure switchs are rated for high current draw.

[bx23barry]

::Kilby Enterprises::

[Soundguy]

Wired properly you can use most any electromechanical pressure switch with the correct pressure setting. Just don't run the main power to the compressor through the switch, run it through a relay. Not all pressure switchs are rated for high current draw.

He could get a well head pressure switch.. if he could get one in his pressure range.. or one with enough adjustement to do so.. etc..

soundguy

[Iplayfarmer]

I was hoping that a few people would chime in that I could just use a 120 volt switch like a well head type switch.

Wouldn't the well head switch handle plenty of current without having to go through a relay.

[allenr]

Yes you could use a 120V pressure switch to operate a magnetic clutch, without a relay.

I used a 240V pressure switch to operate a 12V magnetic clutch that draws 4.7 amps.

Was warned to use a relay as the greater 12V current could cause the contact points in the pressure switch to burn.

Decided to try it without the relay and it's now done two pruning seasons of operating a compressor, each season about 16 - 17 weeks and about 54hrs a week.

[Iplayfarmer]

Yes you could use a 120V pressure switch to operate a magnetic clutch, without a relay.

I used a 240V pressure switch to operate a 12V magnetic clutch that draws 4.7 amps...

What kind of magnetic clutch is that?

I was just thinking I'd get a PTO clutch off the bottom of a lawn mower, but yours looks different.

[Soundguy]

That's funny that they told you you needed a relay.. 12v at 5a is 60w.. 240v at?20a ( well current )is 480w.. and lots of cycle times. 60w ain't nothing...

soundguy

Yes you could use a 120V pressure switch to operate a magnetic clutch, without a relay.

I used a 240V pressure switch to operate a 12V magnetic clutch that draws 4.7 amps.

Was warned to use a relay as the greater 12V current could cause the contact points in the pressure switch to burn.

Decided to try it without the relay and it's now done two pruning seasons of operating a compressor, each season about 16 - 17 weeks and about 54hrs a week.