Adjusting Pressure Switch - Only one adjustment nut..

I think I have a Square D PumpTrol pressure switch.. That is what the cover says anyway. BUT there is only one adjustment nut on the switch. I've looked all over the internet and have not come across a switch similar to mine.
A picture is attached, I'm guessing that this nut would adjust BOTH the cut-in and cut-out pressures at the same time??

Currently the pump cuts in at about 50psi and cuts out at about 60psi. What I would like to do is keep the cut-out at 60psi but lower the cut-in pressure to about 40psi so that the pump doesn't need to kick in so often.
Would there be a reason that it is set up right now with only 10psi differential?? Is it better for the pump to run for a longer period of time or kick on and off more often??

THANKS,
James.

There are about 100 different Square-D pumptrol switches, each slightly different. Yours does not have a differential adjustment.

You could replace the switch with one that does.

You might want to replace your gauge also. I have never seen any squard d switch that you could get below a 17 lb differential with. I think your gauge is telling you a fib.

bob...