URGENT: I have 2 ?'s about adjusting a 40/60 pressure switch

I have a Well-X-Troll air tank and the factory setting is at 30 psi. I was given a new square D 40/60 pressure switch to use by the dealer where I bought my new Goulds well pump and motor. After replacing the pump and motor, I also replaced and updated the wire to 3 wire instead of the 2 wire it originally had because it was bad, 200 ft of it from the well pump to the pressure switch. I am hearing some chatter now. What should the tank pressure be now? And, what should the cut on/off be now?

Any help would be great!!

Chatter usually happens when the pressure switch is too far away from the pressure tank. The 40/60 switch with only 30 PSI air in the tank should not hurt anything or cause a chatter but, 38 PSI air would be more precise with a 40/60 switch.

what about the cut on and off? if the pressure should be at 38 psi.

The cut-on/cut-off is 40/60 psi if that is what the factory setting is on the pressure switch. A 20 psi differential is standard.
You can adjust it usually by turning the adjusting nut(s) on the pressure switch clockwise to increase pressure or counter-clockwise to decrease pressure.
Whatever it is set at, the pressure tank should be about two psi below the cut-on. That's why valveman told you that 38 psi should be the pressure of the pressure tank witha 40-60 switch.
To check the pressure of the tank, the pump should be off and the water pressure drained down. Check the tank air pressure with a tire gauge. If it is too high, bleed a little air pressure off. If it is too low, add air with a bicycle pump or portable tank or compressor.
Good Luck!
Mike

The bladder should be charged to 38 psi only if the switch is set to 40/60.

The factory pre-charge of 30 psi is simply so the tank is immediately useable without permitting rapid cycling in a typical setup even though its pressure still needs to be adjusted to match the switch's cut-in setting.