cut in/cut out pressure

[jayg]

i'm in the process of linking two 150L 3hp compressors,
i have set both to cut out at 120psi but the cut in pressures are miles apart.
one cuts in around 95-100 psi and the other at around 60-65psi,
is there any way of adjusting the cut in pressures or is it just how the switches are set from the factory?
ideally i was wanting a difference of around 10 psi cut in pressures between them both.
adjusting the cut out pressure on both switches doesn't seem to alter the cut in pressures either.
i have had a quick search on the net and seen a couple of pics of switches on other compressors with two adjustment screws but the switches on my compressors only seem to have one.

 

[Shox Dr]

Turn off the leccy and remove the cover from the pressure switch, the one with the push/pull on/off. inside there will be two screws one for max, the other for min

 

[rtbcomp]

The cheaper pressure switches have a fixed hysteresis (the difference between cut in and cut out). Some switches with two springs also have fixed hysteresis, the two springs are adjusted simultaneously to set the cut in/cut out pressures. The hysteresis adjuster is sometimes marked with a triangle, to signify 'delta'.

Try to set the switches so that the motors switch at different pressures to avoid mains surges.

 

[rtbcomp]

Turn off the leccy and remove the cover from the pressure switch, the one with the push/pull on/off. inside there will be two screws one for max, the other for min

Not seen that, they are usually cut in/out and difference between cut in and out.

 

[Shox Dr]

It's a while since I've been in one, so you may well be right

 

[tigler]

I have seen pressure switches with independant screws for cut in and cut out, they tend to be the ones with push buttons for on and off instead of the single pull switch.
It is true that the most common type are single adjusters though.

 

[jayg]

it looks like both of mine are just single adjustment fixed hysteresis then.

probably the best option from here then would be to buy one switch that adjusts both and exchange it for the one that cuts in @ 60-65psi so i can set it to cut in around 85-90psi.

can anyone give me a link or point me in the right direction to one that can adjust both pressures?