No, I do not see any small bubbles in the house water - I know what you are talking about though. We had them when the first pump was starting to run out of water - looked like a light froth when you ran the water.
I think that our system - if it has any type of check valve - would only have 1 valve (at pump), not 2, as there is nothing above ground that even remotely looks like a check valve. I'm going to go ahead and talk to a well company too - they may have some experience with this type of thing. Being older and hopefully slightly wiser this time I will find out up front what's going on. To their credit at least, I was never billed for any of the pump work that was done, but I also think that this situation should have been checked out. I think that they installed the pump, ran it to check the drawdown, then took off.
I also wanted to add that there is no problem with water volume, pressure, or quality other than that cut-in intitial burp.
Thanks for your help and patience [img]/forums/images/icons/wink.gif[/img]
I had a problem at mycabin with the checkvalve after the pump because the pressure switch was on the pump But you don't have that problem. A check valve before the pump cured my problem. "Dankoff solar" website tells how to set and what tank pressure to use.
Pressure adjustments are made at the pressure switch. On a standard switch there are two adjustment nuts, with a spring under each one. Turning counterclockwise will lower the settings. You will see the result by watching the pressure gauge as the pump cycles on and off. FIRST, loosen the nut on the LONGER screw. This will reduce both cut-in and cut-out pressure. Set it for the CUT-IN that you desire. Second, adjust the nut on the SHORTER screw. It adjusts the CUT-OUT only. Cut-out pressure should be around 2/3 of the cut-in pressure.
Once the pressure is set and everyone is satisfied, reset the precharge air in the pressure tank. This will maximize its storage and minimize on/off cycling. To reset the precharge, first make note of the cut-in pressure. Now shut off the power to the pump. Release water until the pressure gauge drops to zero. Measure the pressure of the tank's air bladder using a tire pressure gauge at the fitting on top of the tank. Set the air pressure to 2 or 3 PSI less than the cut-in pressure. Restart the pump. Finally, write down the running time per cycle. Write it on the wall, so the performance can be checked later to detect pump wear or other problems.
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Yeah, it sure sounds like a check valve problem of some sort. Imagine a spring type check valve at the pump. It holds as long as the pressure is enough to overcome the spring (a normally open valve in this case). As soon as the pressure drops to the spring load it opens and dumps everything out.
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Well, no. Check valves (in water systems) are designed to hold agains pressure from the discharge side. i.e., they only open when pressure rises above the system pressure. Usually they are a flapper or poppet type opening towards the discharge side.
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It was also mentioned that the pump is 280 feet down. That is a tremendous amount of pressure head to the pump. That may be a factor of some sort too
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The only head pressure would be the distance from the water level to the top of the well. Pressure of water inside the pipe is balanced by pressure outside the pipe. There is a question of inertia starting a long column of water moving tho.
All in all, in spite of years fooling around with wells and pumps, I have no clue at all why the pressure would drop to almost nothing as the pump starts. [img]/forums/images/icons/confused.gif[/img]
[img]/forums/images/icons/tongue.gif[/img] Dear Shev-Lay, One of the reasons that I hesitate to get involved in these discussions is that after spending years and years in the pump and water supply business I have learned that the general public operates on a set of almost-truths and it's difficult to break through that barrier to actually get them straightened out. [img]/forums/images/icons/crazy.gif[/img] What is going on with your setup is this: The hydro-pheumatic aspect of the system is entirely maintained by the bladder tank. As long as the bladder is slightly off the bottom of the tank, there is pneumatic. As soon as the bladder bottoms out, it's strictly hydro, and as you know, water doesn't compress, so the system pressure goes to zero. As soon as the system pressure goes to zero, the pressure switch......which is probably set somewhere in the thirties for "on" .....feels the pressure drop and starts the pump. THAT's IT....end of story. [img]/forums/images/icons/tongue.gif[/img] What has to happen is you will need to adjust such that the pump starts BEFORE the bladder hits bottom.....while the system still has some semblence of pneumatic left in it to maintain pressure. The bladder tank is overcharged for the cut-in setting of the pump. You can leak the bladder tank down or raise the cut-in setting of the switch. [img]/forums/images/icons/smile.gif[/img] That should get things working like they are supposed to. [img]/forums/images/icons/crazy.gif[/img]
I did use those type of directions to check and set the pressure switch settings - thanks.
CJ Dave, as one member of the general public who's not worried about barriers, this forum and the help that it offers are invaluable.
What you say makes good sense as to what's happening and what I need to do. The description of hydo/pneumatic helps me understand what's going on, especially that picture about the air bladder being off the bottom of the tank.
I'll double check the pressure switch settings and then start by increasing the cut-in psi incrementally. Great info - thanks very much!
I went back and first lowered the cut-in pressure just to see what happened. The result was that the initial brief lag in water pressure became a 3 second delay. This goes along with what CJD had said. I then left the cut-out pressure (62 psi) alone, but then began to slowly raise the cut-in pressure. At 45 psi I could see that the lag in water pressure had almost gone, but not quite. Increasing it beyond this point really did not make a difference.
I did not tinker with the tank air pressure - it is set at 38 psi (reading taken with pump off, no water pressure). What I'm a little confused on is that when I take the reading with water pressure restored, the reading is lower than 38 psi, about 24-28 psi. If the bladder is being compressed, wouldn't the pressure reading be higher?
Also, does not having a control box make a difference in all this? The original 2hp pump had a Franklin box, the new 1.5 hp pump just has the wire from the pressure switch dissappearing down into the shaft. When the well company replaced the pump, they removed the box.
Thanks.
At one time, most single-phase submersible motors were three-wire motors with the capacitors in the above ground control box. In later years, two-wire units were made such that they eliminated the control box and above ground capacitors. I always kind of preferred the control box models since you could more easily fix a no-start problem. That IS strange about the bladder tank having MORE pressure when the system pressure is zero than when it is at normal head. [img]/forums/images/icons/crazy.gif[/img] If I wuz you, I would definitely dump some pressure out of the bladder tank. [img]/forums/images/icons/tongue.gif[/img] As it is, you aren't getting the storage that you could have, small though it is. You don't want to be operating as close to "bumping" the bottom as you seem to be. The bladder will usually last longer if it stays up off the bottom just a bit. [img]/forums/images/icons/tongue.gif[/img]
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