One set of points on my pressure switch continue to arc and get burned to the point that they no longer make proper contact and my well pump shuts down. I clean them up and the pump continues to operate for about 3-4 days and then the problem repeats. The pressure also surges continuously.
This is a two wire system without a tank. Can anyone tell me why this problem occurs and how to remedy the problem?

Thanks for your help

The motor windings sound like they're pulling too much amperage. Have the windingd checked before you replace the pump control. Good luck. Tom

Without a tank? What is this pump used for? I cannot imagine a system with a pressure switch which does not have a tank.

The well is the primary water source for our house. The well is about 140 feet deep and puts out about 100 gallons a minute. We did not have this problem until our third year on this system.

Claypa, I have been dealing with wells (strictly an interested amateur) for a while now. I can tell you that 100 gallons a minute is pretty significant and far more than most residential setups. At any rate, for the system to have pressure when the pump is not on, I would think that you must have a pressure tank. I've never heard of any other setup and can't imagine one other than a gravity storage tank which would have to be up high (attic at least).

The cheapest stab at a fix is a new switch. They can be bought for twenty or thirty bucks if you can do the install yourself (see link below). Not hard, but it does require some working knowledge of electricity. Rule #1... turn off the breakers to the pump before you start! That is assuming that this is an ordinary system such as those found in most homes. But at a 100 gpm, you might have something above the ordinary.

If that is not it, then you are looking at bringing in an electrician to see how many amps each of the two "legs" of the 220 volt feed is drawing. It may indeed be a pump problem. If so, then the pump has to come up for repair... not cheap.

SQUARE D CPD FSG2J21CP SQUARE D PRESSURE SWITCH 30-50PSI (http://www.acehardwareoutlet.com/(ru2b1y45swtgei55yq0ztp55)/ProductDetails.aspx?SKU=49449)