Submersible Well Pump question
Submersible Well Pump question
(OP)
What will happen in a submersible well pump installation containing a pressure tank at the top (floor level) if the air in the pressure tanks leaks off (not air at all)?
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Submersible Well Pump question
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RE: Submersible Well Pump question
A sketch would help a lot....
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RE: Submersible Well Pump question
RE: Submersible Well Pump question
RE: Submersible Well Pump question
All this will change is that the outlet won't have any pressure maintenance and so any small usage or leak will lower the pressure very quickly and hence the pump will start, pump for a few seconds to pressurise the system again then turn off.
Sop you pump could get a lot of starts. If your outlet opened for flow the user would get a spurt of water then nothing, then lots of water as the pump kicks in.
The accumulator with air in it smooths all of that out.
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Also: If you get a response it's polite to respond to it.
RE: Submersible Well Pump question
The pressure never reaches the cutoff pressure set at the pressure switch (4 bar). Pressure stays at around 3 bar all the time
If pressure tank has a precharged 0 bar (no air) the the pump will start and stop very often (as you said LittleInch).
I think that there is a 2nd problem here (besides no precharge at pressure tank). I am suspecting that the pump is spinning at the wrong way. Does submersible pump have spinning direction or they work the same in both ways?
RE: Submersible Well Pump question
The options are:
Your pump is either spinning the wrong way ( only really possible if you have three phase supply),
Your pump is undersized for your requirement (cannot reach 3bar at no flow)
Your pressure set-point is too high ( reset to 2.5 bar?). Why is this so high? for a domestic propert you don't normally need 3 barg
Your pump has a fault
Your electric supply is the wrong voltage or frequency for the motor
Does this help?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Submersible Well Pump question
The pump is 3 phase supply and it`s been connected a couple of days ago
The pump is not undersized. Same size of pump has been working for long time w/o any problem
Pressure value is high but this is not the problem because the pump used to reach this pressure w/o problem
Pump has a fault: dont think so. Is a new pump
Electric supply: ok
I think that it is spinning the wrong way. Tomorrow I will change rotation direction and see what happens
RE: Submersible Well Pump question
Let us know how it goes. Sounds like it might be the answer - typically you'll get about 60-70% of the proper head by spinning the wrong way so you should get about 5 bar?
Double check the required voltage and frequency of the pump match the previous unit. Also just because the pump is new doesn't mean it isn't broken or has a fault. The difference between a 50htz unit and 60 htz unit is quite large.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Submersible Well Pump question
If cutoff pressure is reached then this was the 1st problem
Then I will precharge the air tank and check pump on/off cycles
RE: Submersible Well Pump question
RE: Submersible Well Pump question
RE: Submersible Well Pump question
The whole point of the air in the tank is to provide a pressure buffer. Without the air, the instant the water is turned on at a faucet, the pressure drops enough to kick on the pump, the pump will instantly overcome the cutoff point (because the pump generally has a higher capacity than the flow out of the faucet). As long as there is any demand on the system, the pump kicks on and off every few seconds. This can burn out or overheat the motor quickly.
To address your question about the pump never reaching the 4 bar pressure, as others have said, if it's a 3 phase supply, switch any two leads, and see if that helps.
RE: Submersible Well Pump question
Do you mean it runs continuously 24/7?.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Submersible Well Pump question
It has only been installed for a couple of days so maybe hasn't burnt the motor out yet.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Submersible Well Pump question
Is this tank a bladder tank, ie., a diaphram between the air and the water?
A pump curve would be helpful as would contacting your local domestic water supply guy for some advice.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Submersible Well Pump question
RE: Submersible Well Pump question
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Submersible Well Pump question
Pressure tank: Has no air at all. I have dismounted and disassembled the tank. The bladder is good
Pump works with out stopping and pressure stays at 3 bar
Bimr: I do not know the water level in the well
cvg: I didn't think about that. Thanks!
Artisis: yes 24/7
This is the tank: LS H 60
http://www.varem.com//pg.asp?cd=1014&mnpath=/0...=
I am going to precharge the tank again, install it and see what happens
RE: Submersible Well Pump question
PUMP CURVE,WHERE IS IT?
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Submersible Well Pump question
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Submersible Well Pump question
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Submersible Well Pump question
Not everyone logs in as much as some of us do.....
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Submersible Well Pump question
Air must have leak out through the air valve. I changed the seal of it
I have installed the pressure tank and the pressure still does not raise above 3 bars. I reset cut OFF pressure to 2,8 bar and cut ON to 1,0 bar. The system seems to be working good so far but pump pressure used to reach 4 bar.
I dont know who or why it was set to 4 bar
I dont have the pump curve. All they could told me is that is a 1 HP SAER pump
RE: Submersible Well Pump question
Glad to hear you've fixed it.
To be frank, if that's the level of technical knowledge coming back from the supplier / installer, then how they can actually say this is "identical" to the one you replaced is pushing it. I had a quick look at the SAER website and there are not only many types of pumps available, there are many versions of those pumps. There are a number of ways a "1hp" pump could be configured to give you a slightly lower outlet pressure.
So unless you can get the model number, pump curve and then compare it to your old one, I wouldn't bother any more. You have running water and the pump turns off until it's needed. Job done.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Submersible Well Pump question
Pressure tanks is 60 liters and only half of it is filled with water (estimated)
Precharged pressure is 2 bar (I should lower precharge pressure to get more water into the tank)
Any comments?
RE: Submersible Well Pump question
RE: Submersible Well Pump question
will do that tomorrow
RE: Submersible Well Pump question
SAER type B12
6400 lts/hr at 25m
1600 lts/hr at 50m
RE: Submersible Well Pump question
http://electrapomp.com/catalog/saer_sondajni_pompi...
page 14
FS-98A/15
RE: Submersible Well Pump question
The pressure tank needs to be filled with air when there is no water in the tank, and the air pressure should be a little higher than to the pressure required for the pump to turn-on.
RE: Submersible Well Pump question
1. The cut-in pressure for your pressure switch should be the sum of the pressure required at the highest point in your system (ie, maybe showerhead) plus the elevation from the pressure tank to the highest point plus a bit for friction losses in the pipework.
2. The cut-out pressure to equal the cut-in pressure, plus 1 -1.5 bar, BUT NOT exceeding the maximum head the pump can deliver at the tank, this is measured from water level in the well plus friction loss to the tank plus the cut-out pressure setting.
3. The tank air pre-charge should equal approx. 90% of the cut-in pressure. (ensure there is no water pressure acting on the diaphragm).
Set your system up as above and you should have a smooth and fully operating system.
P.S. Do you know the operating ground water level, this is an important piece of data, if unsure, possibly you can test the developed head pressure against a closed discharge valve at ground level or at just prior to the pressure tank -- the pressure at this point may influence your overall system -- it is required information.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Submersible Well Pump question
The tank is supposed to be a 60 litre tank. The link provided by the OP gives an excellent formula for working out the volume of a pressure tank
However for a tank to go from 1 bar to 2.8 in 10 seconds would mean a volume change of around 20litres according to the tank website = a flow in of 120 l/min.
Maximum flow from the pump is only 46, but at what you can only assume is that it is working close to max head, flowrate is circa 15 to 20 l/min, hence 10 seconds of flow = 2.5 to 3 litres.
It doesn't sound possible for a 60 litre pressure tank to go from 1 to 2.8 bar with only this volume unless the bladder is very small or the system is somehow compromised.
lukin, your pump data implies that the water level is 60m below your tank level ( max head 92m, static head 3 bar). Does that sound right?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Submersible Well Pump question
I could not go to the site today. I will check myself how long does it take one ON cycle next thursday
RE: Submersible Well Pump question
It takes 1 min and 30 segs to go from 1 bar to 2,8 bar
RE: Submersible Well Pump question
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.