How long should submersible well pump stay on

Rkh

Member
Have a well pump 220v submersible pump, 20 gallon tank, 30lb-50lb pressure cut on cut off. How long should the pump run? Mine runs only 21 seconds, checked tank pressure-28 lbs, water drained from tank.
 
Sounds like to me your pressure tank is water logged. Needs more air in pressure tank so pump will run longer. Air compresses and water dont
 
How long "should" the pump stay on? You're missing one variable - available GPM. We have a shallow well and it's only 2", but we also can only get about 2GPM out of the well. So a 20 GPM pump is still only pumping 2 GPM here.
 
With the water drained from the tank as you had it. Can you rock the tank back and forth, if yes the tank is ok, if you feel water sloshing around or you can't move the tank time to replace the tank.
 
28 pounds is the correct pressure for your cut on. The question you need to ask is how long does it take to fill the tank to 50lbs and how many gallons does that fill yield. If you are with in a couple of gallons of stated capacity,I am guessing you are ok.
 
If you mean that every time the pump starts from the low pressure 'on' cycle, it takes 21 seconds to reach the pressure limit and stop, it could be just fine, or it could be waterlogged. meaning the tank has insufficient air, or a bad bladder. If the amount of water available between stop and start seems to be 5 gallons or so, I would say it is ok. If it runs with very little draw down, I would suspect the tank. Jim
 
Sounds good to me.

Actually, what's more important is how long it DOESN'T run. If you have a shallow well and a powerful pump, it won't take long to refill the pressure tank. But if you can draw a few gallons from a fully charged tank before the well kicks on, you're good to go.
 
I just timed ours, it only ran 16 seconds! That is with a fairly new 20 gallon bladder tank and set at about 30-50. I am pretty sure the tank is still in good condition and properly pre-charged. Last summer we were without power to the pump for 31 hours as our generator is only 120v, and we did not run out of water. We carried water from the lake to flush the toilet and used the faucets very sparingly. We should probably have a bigger tank or a second one. One reason for the short run time is a very high water table, + 12 ft!
 
First make sure your presume tank isn't water logged. The motor company's want a pump to run at least one minute if it's a jet pump or a submersible. On a jet pump it takes that amount of time for the fan in the motor to cool the windings down.the other pump takes that long to bring enough cold water by to cool the motor too. Ideally you should have a large enough tank to have that happen.due to space some times that's tough to do.
 
(quoted from post at 09:25:50 04/23/17) First make sure your presume tank isn't water logged. The motor company's want a pump to run at least one minute if it's a jet pump or a submersible. On a jet pump it takes that amount of time for the fan in the motor to cool the windings down.the other pump takes that long to bring enough cold water by to cool the motor too. Ideally you should have a large enough tank to have that happen.due to space some times that's tough to do.

Huh? Never heard of a pump running that long unless you are running a lot of water. Never heard of a motor getting hot so that it needed cooling time that quickly. Never heard of a water cooled electric motor. Maybe I need to get out more.
 
[b:40461a9473]Russ from MN -- [i:40461a9473]One reason for the short run time is a very high water table, + 12 ft![/i:40461a9473][/b:40461a9473]

So your water table is 12' over your yard?

Have never heard this type of phrasing before. Please explain. Tried doing a web search but must not be putting in the correct words.
 

A residential well pump is sized to flow 8-12 gpm on average, when using a 40-60 lb pressure switch a 20 gallon pressure tank will draw down 5.35 gallons before the pump kicks on.
With the faucets turned off the pump should fill the tank up and shut off in around 15 seconds, with a faucet running it would take a little longer, these numbers can vary according to the actual pump output.
A average home faucet flows around 3 gallons per minute so even though the pump only runs for 21 seconds in you case it should be shut off for a minute or more before turning back on.
Keep in mind that with a outside hydrant flowing around 8 gallons per minute the pump will come on sooner but run for a much longer time with the hydrant turned on.
It doesn't hurt a pump to run for extended periods, what kills them is short on, off, on cycles.
If your pump fills the pressure tank in 21 seconds but is only shut off for the same about of time or less you could have a defective pressure tank or one sized to small for the pumps output.
Personally if your had room I'd rather have a larger pressure tank to increase the difference in the pumps cycle times. Run a little longer and off a lot longer, again this is without any faucets running.
 
I thought someone would question that statement! I don't know if that is the proper way to describe it, but here is how it
is. There are many artesian/flowing wells in our area, and ours has what I understand is called a packer above the pitless
adapter to prevent the well from overflowing. I shut the power off to the pump and bled off the pressure, then I carried the
garden hose up the outside stairway going to the upstairs of our garage. Water continued to come out until I got about 12
feet above the ground, then it slowed and stopped. As soon as I lowered the hose water started coming out again. So I say we
have +12 foot water table, we live on a lake and there is a lot of higher ground west of us.
 
In the paper mill that I retired from we had some 7500 hp motors that were water cooled, there was a large radiator in the
top of the motor and a fan circulated the cooled air through the windings. Can you imagine how hot a room would be with
60,000 hp of motors running at peak load if they were just air cooled?
 
Ah, artesian well. Now it makes sense.

We don't have any artesians in this area to the best of my knowledge, but don't need them either. Friend stopped by yesterday and we were joking about how careful the neighbors had to be discing their land so as not to puncture the dirt and sink us all!! :lol:
 
I had the same 'problem' with our submersible. Pump was running maybe 25 seconds, and cycling back on every 3ish minutes. Only had a 20 gallon tank, set 30-50 on-off. Added a 44 gallon tank to it, so the pump now runs about 2 minutes, and rests for about 10 minutes, while using about 2 GPM.
 

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