Losing System Pressure - intermittent

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Losing System Pressure - intermittent

Postby foothillsjim » Mon Sep 08, 2014 7:46 pm

After moving into an 8 year old home a year ago, we are now having erratic performance from
our Well & Water Pump system.
CentriPro CB07412 3/4HP Pump Control from March 2009
Square D Pumptrol 9013FSG M4 Pressure Switch (low pressure cut off), set to 30/50
86 gallon pressure tank at about 28 PSIG, ProFlo 2006

We have lost pressure in the system about 4 or 5 times in the last 4 weeks - I think always while our irrigation
system (maybe 3 GPM) was running in the early morning. Well was tested last year at 11 GPM (we are in Central California - very dry the past couple years).

When we have been at 0 psig the 4 or 5 times, usually moving the pressure switch arm to start solves the problem -
the tank reaches 30 psig in just a couple seconds (so I think the bladder is OK, but have not verified).

This morning, about 30 minutes after the irrigation system started running, I could hear the pump motor
cycling on for 5-15 seconds, then off for 45 seconds or so, then back on, then off, etc. It did not seem to be
pumping (much). Inspecting the pressure switch showed that all contacts were closed - power to the pump control.
Moving the switch are to start did not help (contacts were already closed), but moving the arm to off, opening the contacts, and back to auto/run seemed to fix the problem. It seemed that resetting the pump control (or the motor circuitry) got things going.

I think this same problem is what has been happening - motor/pump gets into a short cycle mode SOMEHOW, and then the irrigation system drains the water from the pressure tank in 10-15 minutes, and the low pressure switch keeps everything shut down until its lever is manually moved into start.

So I am wondering what is creating this intermittent problem?
(When I ran a water test later today, at about 6-8 GPM for about an hour I had no problems - pressure switch always
turned the pump motor on at 30 psig, and the pump ran the tank up to 50 psig over and over).
Posts: 1
Joined: Mon Sep 08, 2014 7:22 pm

Re: Losing System Pressure - intermittent

Postby dlamp67 » Tue Sep 09, 2014 8:15 am

My first gut feeling was that the pump was breaking suction, but, after reading further, I think you have an issue with pressure the switch. If by operating the low pressure cut off switch, then all of a sudden the system is operational, leads me to believe the problem is in the pressure switch. Even though the contacts look closed, you could be experiencing a situation where one side may not be making good contact. I would try replacing your pressure switch. If afterwards, you still experience the problem, then disconnect your discharge piping and allow the pump to run open discharge to determine if the pump is breaking suction.
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Joined: Mon Jul 30, 2012 1:46 pm

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