Hello and thanks for any help you can offer.We have a new 4 inch well that is 140 foot deep. A steel casing goes down 90 feet. The well is only good for about 5 gal. a min. I have a 20 gal. pressure tank. Pressure switch is 20/40. The water level in the casing is about 60 feet. The driller told me not to set the pump below the casing. I dropped a brand new wayne 1/2 hp. pump to 85 feet and got it started. The water was a little dark colored and i let it run for about an hour at a slow pace to try and clear it up. I dont think the well ran dry. After an hour the pump quit and would not build up the pressure after that.I think the thermal overload had tripped when it first stopped but after that it couldnt build up the pressure to 40. I brought the pump back and exchanged it. 2nd pump same problem after 3 hours. Afraid to try again without changing something. HELP?