Well and Pressure tank problem

[Jeff]

I have recently experienced well based water supply where the pressure in my pressure tank drops to zero and eventually repressurizes. The entire assembly is just over two years old. It uses a submerisble pump (sorry, no make and model info) with a 20 gallon bladder pressure tank. The well is

380' and had (at drilling) a 7 gpm flow, and we've been getting a fair bit of wet weather over the past 2 years, so I'm assuming that I haven't run the well dry. I've recently adjusted the cut in/cut out in order to get some additional pressure in the second story (though the adjustments weren't too significant, from 45-72psi to 50-74 psi). There is approx 38 psi above the bladder. This problem started approx. 2 weeks after making that change.

What I've seen from my trouble shooting. The pressure switch seems to be working correctly and there is power to the switch. While watching the pressure gauge, I see a spike approx. once per minute as the ?pump? tries to kick on. Eventually it catches (not sure if that's the right term), I can hear the water flowing and the pressure rises to the normal cut off and the pump cuts out. I can then run the water, decreasing the pressure in the tank and watch the pressure swithc cut over at the cut in pressure... though the pump doesn't necessarily cut in.

Some other data points... from a zero pressure, I've seen the pump catch, and then cut off about a second after, but most of the time, it just kicks up the pressure (to approx. 40 psi) and then stops... this probably takes

1/2 second.

Any help would be greatly appreciated.

Regards,

Jeff

[Art]

Are you actually seeing the pressure switch trip at the right time? If not I would pull off the pressure switch and clean the pipe it connects to. Gunk in the pipe may prevent the switch from feeling pressure drop even though a guage next to it on another pipe sees the drop..

[Jeff]

The pressure switch is tripping at the appropriate times (or at least consistent with the gage), it has settings for both cut in and cut out pressure and I see the switch pop at the appropriate pressures. That said, it is as if there is something else in the equation. I'm assuming the pump is what pressurizes the tank... and even though the cut in is activated the pump doesn't immediately activate. It seems the pump tries to cut on about every minute. Most of the time, I see just an instaneous boost in pressure, but every once in while it catches, I hear the water flowing and the pressure tank pumps up to the cut off pressure (just over 70 psi). So I have water periodically, as long as I don't use copious amounts at one time.

[Speedy Jim]

That is a *very* deep well and the pump has a lot of head pressure to work against at startup. Sounds to me like the motor is having trouble developing enough starting torque; thus the repeated start attempts.

Try setting the pressure switch to a dramatically lower pressure, like 20/40. If the pump now works normally, the pump performance is marginal. (This is just an experiment to gather info.)

Is the pump too small? Wrong impeller config? Bad start capacitor? Bad motor? I'm not enough of an expert to answer that...

Jim

[Jeff]

[Playintennis5274]

on your pressure sw. how do the contacts look? >ank and watch the pressure swithc cut over at the cut in pressure... though

a-lot of times after repeated heavy use , the contacts will wear un evenly or from arcing they get a coating and they will only sometimes allow the current to start whatever it's supposed to . some one else mentioned that was a-lot of pressure for the pump to overcome because the well is so deep . He has an excellent point . maybe leave the cutoff where u have it 70? u said but decrease the cut in to wayyyyyy low.

[Harry K]

It isn't the depth of the well but the height of the water in the well that determines the head pressure. A 400 ft well with the pump at 350 ft can have 0 pressure to overcome if the static level is at 350 ft or about 150 psi if static is at ground level. Neither would be realy significant factors. I have no solution for the OP other than call a pump man. I think his problem is going to be with the pump or its wiring.

Harry K

[Art]

Wonder if you were sold a lousy pump. My original Gould pump lasted 12 years. THe replacement was crap for the 3 years it held up.

[Michael Strickland]

I had a similar problem a few years back (IIRC was about 2 1/2 years after well was drilled) and it turned out to be that the wire had been hitting the side of the shaft and had worn the insulation through. The pump would work, but not reliably , then one day it quit altogether. Don't recall the cost for repair, but was not too bad IIRC. The repair used heat shrink covering over crimp couplings to fix the insulation problem and a spacer attached around the pipe and wire at that point to prevent further contact with the wall.

The explanation I got was that when the pump turns on, the torque causes the pipe and wire to swing a bit. If there are any protrusions along the wall of the shaft, they will wear the wire in two. I would think that the pipe could possibly also be damaged, but the wire is more likely as it has a little slack in it compared to the pipe.

Later, Mike (substitute strickland in the obvious location to reply directly)

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[L. M. Rappaport]

On Sat, 11 Dec 2004 18:40:39 -0500, Speedy Jim wrote (with possible editing):

Actually, it isn't the depth of the well but the depth of the top of the water level that determines the net pressure.

-- Larry Email to rapp at lmr dot com

[Jeff]

Pretty interesting... I can't think of anything that would disprove that theory... Also, by increasing the pressure in the tank and reducing the delta between cut out/cut in I would have exacerbated the problem. I looked at the pump head and thought about disassembling it... but disassembly (well, disassembly without breaking anything) doesn't appear overtly simple. My pump head consists of 8"? round PVC, capped with a flat top, there is also a 1" PVC with standard cap sticking out the top, four nuts positioned symetrically around the top, the water feed (with faucet attached) comes directly out of the center of the 8" cap and the electical conduit runs in via a hole in the top. I loosened the 4 nuts, but this did not seem to free up the top assembly... Possibly I have to dig down to get at the base, but the unit appeared fairly solid when I tried to move it back in forth. Short of disassembly, I'm not sure how else to test. I've placed the call into the installers... arggg....

Re: the suggestion I check the contacts... they look pretty good and once the contact is made... it seems that the pump kicks on and off on its own... though the contacts remain untouched - so I would assume that the pump has power and and something else is causing the issue.

to the trash and I might not catch it.

[Michael Strickland]

It's not overly complicated either. I watched carefully when the repair was done on mine.

Sounds like mine, but mine is 6". Mine also has a 3/4 inch dia. vent which screws into the cap a little way from the center. It's about 3" tall and has tiny slits in it. A convenient place to pour the bleach when it was time to sterilize the well for the county required E. coli test - they require it after drilling potable water wells.

Nope, you're working against the weight of the pump and piping as it's all supported by that top. Takes a bit of energy to get the top up and pull up the piping and pump. Mine's 180' and is fairly heavy - you have to remember that the pipe is full of water unless the foot valve is bad. The nuts compress a rubber gasket to seal the top to the casing.

Probably the best bet anyway. If the insulation is worn, you need special heat shrink coverings to seal the connection when it's fixed. You can probably find these if you hunt around - never have tried. Also, you can watch to see if you want to handle such problems (or possibly replace the pump when it wears out) in the future. The procedure isn't too terribly complicated, but requires more than one person and a certain amount of strength.

The fella that drilled my well did the repair. He used an old auto wheel attached so that it can spin to a homemade stand as a roller to pull the pipe (pipe is black flexible poly) and wire over after he got the top up. The setup had the pipe and wire coming straight up out of the hole, passing over the top of the wheel and then horizontally across the yard. A specialized setup, but it could be done by pulling hand over hand - imagine it would be a lot more exercise though...

Someone has to be at the wellhead to work spacers around the wheel and to pull the pump straight up when it gets to the top - the wheel wasn't high enough off the ground for that, only about a foot or so. Another person has to pull the top of the well out across the yard as the pump is raised. Thus a requirement of at least 2 people - mebbe more for your situation due to the probable length of the pipe.

Let me know how it comes out. I'm still learning about wells and repairs myself (have made an attempt to learn all I could in the 7 years we've been on a well), so I'd be interested in what the actual problem is and it's solution. Could you please use the address below and email the solution to me? My daughter is going to rebuild my computer for Christmas and I expect that I'll be limited to email at work for at least the next couple of weeks since she's gonna be doing the rebuild in her spare time. That being the case, any posting here will probably be gone before I can get it. TIA.

Good luck.

Later, Mike (substitute strickland in the obvious location to reply directly)

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[Art]

My last house was my first and only house with a well. ALso had a water source heat pump so that well really got a work out. Every year the wire would break and every year the well guy would come out a fix it for a fee and we would have no heat or ac while waiting for him. When the pump finally died and he replaced it with a crappy pump that was inadequate I got a new well guy. First time the wire broke he built a 200 foot sleeve out of PVC for the wire. No more wire breaking in that well. If your wire doesn't have a PVC sleeve have one put in.

[Duane Bozarth]

Use snubbers and attach the wire to the pipe...won't be a problem.

[Duane Bozarth]

Drain the pressure tank and see that it is empty...part of the problem may be your tank is becoming water-logged...happens it the bladder/diaphragm develops a pinhole leak...

Second, check the current draw on the pump when it tries to start and run...

Third, the tank pressure (empty) should be two pounds below the cut-in pressure. If it's 20-40, say, the enmpty tank pressure should be 18. If you need higher pressure than about 50, I'd recommend a pressure booster rather than relying on the well pump unless it is really strong.