Low Pressure Cutout

[LeakyMike]

Have an issue with a friends well system.  Intermittent pump cut out when waking up in the morning. He has to go down and cycle to lever on the pressure switch to revive it. Doesn't happen everyday though.  Well company has replaced the switch twice now (which I doubted it was). They think now the water softener is the issue but to me the pressure has to be going somewhere overnight. No external leaks anywhere we have found. I recently installed a new pressure tank but the problem was there before that. He wanted it changed just because of it's age. I'm not sure what pump ( nor does he) is in the well. I suspect it's foot valve or in the pump check valve that sometimes hangs up but this is a deep well ( 130 ft +/-) and 100 feet to the house.  Scratching our heads here.

[Cary Austin]

A low pressure cut off switch shuts the pump off any time the pressure gets about 10 PSI lower than the pressure switch start setting.  A leaking check valve cause cycling when no water is being used, but does not cause low pressure.  Pumping the well dry, using more than the pump can supply, power outages, and having too much air charge in the tank are what causes a low pressure switch to trip.  Make sure the air charge in the tank is 10 PSI less than the pressure switch start pressure.

[LeakyMike]

Thx Cary but yes I did set the air psi to 28, He has a 30/50 Square D switch. The system works fine during the day of normal use. They never have a water run out situation the issue is in the morning at the start of the day. The static pressure is gone in the morning (zero on the gauge) and a tripped switch. I now have him shutting the house side of tank manifold off at night and keep a record of what is found in the morning. This will eliminate the softener system that the well people say is maybe the issue . The pressure is going is the big question.

[Cary Austin]

Set the air pressure at only 20 psi.

[LeakyMike]

OK Cary I will give it a try but what is your reasoning behind that suggestion?  I've always understood that minus 2 psi below cut in was the proper set up, 

[Cary Austin]

Whatever the air pressure is in the tank is where the low pressure switch will turn off the pump.