Pump question

[coppermonkey]

Hey Folks,
I have been plumbing for about 15 years an have not seen this problem before. My client has a deep well with a sumersible pump and a bladder tank that was installed by some hill-jack. The problem is that the pump switch cycles on and off as if the tank is water loged, but it is not. The thing is that when the pump turns on the PSI on the gauge jumps instently about 15 pounds and then the pump turns off and then the PSI drops 15 pounds and the pump turns on and so on and so on. I know that sounds like the tank but nothing is wrong with the tank. I have checked the psi in it and it is set 3 psi below the cut in psi and has no water in it. I adjusted the switch this morning so it came on at 30 and off at 56 witch seemed to be more of a range than the jump and drop at turn on and turn off, but then it started again this evening. Any ideas? Thanks

[PLUMBILL]

It's been along time since I did alot of pump work but; did you change out the air volume control?

[coppermonkey]

This system has a bladder tank not a traditional type tank with a air control. Thanks for youy input though.

[plumberfourthg]

It sounds to me like you have too much air pressure in the bladder tank. When the line pressure drops the pressure switch turns on the pump, because there is too much pressure in the tank, the air can't compress so the pressure surges in the line shutting off the pump. It would behave nearly the same as a water logged tank. Try lowering the pressure in the pump tank and/or using a different gage to check the bladder pressure.

[martinnman]

Well, I think this is the easiest solution is to adjust the pressure switch, located on the pump control. Sometimes the switch is set too high or too low for your particular application. Setting the "off" the pressure is as simple as turning the adjusting screw. However, do not make it too high, otherwise the pump must never be extinguished.