In an effort to conquer my Edison bill, I installed solar heat panels for our jacuzzi and dropped a Grundfos 11-sqf-2 pump in one of our 3 wells. No pressure tank, just a 3000 gal. and 2700 gal. storage tanks. The pump pumps into the 3000 gal. tank, overflows into the 2700 gal tank we use out of and from there overflows again onto a row of citrus and avocados. The system works brilliantly, so now my husband has gotten enthused and that's the problem. I have bought another ll-sqf-2 pump to drop into a second well and my husband wants it hooked up to a pressure tank. O.K., that should work just like a pressure float, no problem, right? The problem is that he has a 5 wire ac/dc pressure switch he wants to use. From what I've read, dc pressure switches are 3 wire. My idea of wiring the system is solar power to cu-200 controller then from the controller, 3 wires to the pump and 3 wires (but which 3 wires?) to the pressure switch with the controller turning the pump on and off. He wants to run solar to cu-200, 3 wires to the pump, 3 wires to the pressure switch, and 2 wires from the pressure switch to the pump, assuming the pressure switch will control the pump. I'm no electrician, but I can't see how that would work. It's not for nothing Grundfos pumps are great, and I can't afford to let him burn up either the pump or the control box. He won't listen to me, but he might listen to you. Can anyone out there advise me about wiring a 5 wire ac/dc pressure switch up to a dc pump? Maybe I should bite the bullet and buy one of those way-too-expensive Grundfos pressure switches? My electric bill, by the way, has dropped from hovering around $300. a month to running between $35. to $40.00.