Pre-charge home water accumulator anyone?

[wirednuts]

at the lake here, we have rolling water pressure on well water. we know our pump is old, and when the pump is on the pressure is good but you can tell it shuts off and the pressure drops to about 10lbs over a few min, then the pump comes back on. its very annoying, hard to clean dishes and hard to shower.

so i looked at the relay, and there were hysteresis adjustments. i read the little instructions, and adjusted the best i could tell (pressure gauge was frozen, so i left a faucet running and listened).

results were positive. i now have probably a good 20lbs minimum... you can still tell when the pump comes on but it comes on way before it gets too low, as it should. i have noticed that if i have a faucet on full blast, the pump doesnt shut off. i dont think this is a problem though, its a very old pump (50+ years) so i imagine the flow rate isnt that spectacular.

what im worried about now is the accumulator. after reading up, it seems if you dont have it adjusted right you can damage it. it is the bladder type system, and i dont know if its filled with air or nitrogen. it seems they are all nitrogen...

anyone have experience with these? like i said, it seems more then acceptable now, its pretty awesome compared to what ive been dealing with... but i just want to know if i should try to adjust it properly or hire someone to do it.

i have a lot of home building/auto repair/electronic experience. i wont kill myself. i dont think.

 

[colonelciller]

don't know how to fix your problem... but one concern is burning your pump out if this situation continues for too long.

 

[wirednuts]

don't know how to fix your problem... but one concern is burning your pump out if this situation continues for too long.

how so? the accumulator doesnt really do anything when there is full flow in and out for an extended period anyway...

 

[colonelciller]

i guess i was assuming that the pump would be turningon all the time to try and bring up the pressure... the pump isn't designed to operate like that... on and off all the time. this short cycling is a common cause of pump motor failures.

if that's not actually what's happening then i was mistaken

here are a couple of links that may help you diagnose your issue:
http://inspectapedia.com/water/pumprepair.htm
http://inspectapedia.com/water/ShortCycleCause.htm

 

[wirednuts]

i guess i was assuming that the pump would be turningon all the time to try and bring up the pressure... the pump isn't designed to operate like that... on and off all the time. this short cycling is a common cause of pump motor failures.

if that's not actually what's happening then i was mistaken

here are a couple of links that may help you diagnose your issue:
http://inspectapedia.com/water/pumprepair.htm
http://inspectapedia.com/water/ShortCycleCause.htm

thanks. i found a good link inside those links... i re-adjusted it, its better for the pump now i think. now, even if a faucet is left on, the pump runs for about 2min, then shuts off for 2min. it still gets a little low at the end of its off cycle, but its still better then it was, and the pump runs a little longer now so i think its better because it will reduce the cycles- and keep me at high pressure for about 3min out of 4 now instead of 30sec out of 5 like before.

i also learned how to adjust the tank pressure. its likely that they preset it for 30-50 psi, but i still doubt our pump goes much higher then 30.... so im thinking if i released some pressure it would allow more water to accumulate and further reduce my pump cycles.

so far, i think the pump is safe and i have MUCH more normal pressure. i need to get a working gauge installed, and measure the tank pressure so i can compare the two.

 

[colonelciller]

glad those links helped

I wonder what is the source of the pressure drop though. maybe some water leaking through the pump and back out/down?

 

[wirednuts]

no the pressure only drops when a faucet or something is on.. it was just going way too low before the pump would kick back on.

i took a shower this morning, and soaked all the drywall above the shower. too much pressure! it was like a car wash hahaha

scared again, i turned the small screw out a few turns. this lowers the high end pressure. so now, it has a decent minimum pressure but it doesnt ramp up so high that my shower feels like a hose spraying on me.

i really need to get a working pressure gauge on it. i think its pretty close now, but since it doesnt ramp up as high it will cycle more. it cycled 3 times this shower... so im thinking now that the air in the bladder tank is either too high or too low- but im not messing with that until i can get accurate psi ratings.

 

[colonelciller]

sounds like you're having a good time there

would it be posible to get a larger tank?
how large is it?

 

[wirednuts]

i think its 22 gallon, which is pretty normal i guess. theyre 44gal physical size, but the bladder is supposed to be pressurized to consume about half that.

no plumbers on anandtech.. weird..

 

[heymrdj]

Yeah I don't think a pump will help you here. Depending on the pumping distance and what not a bigger tank sounds like what you need . To increase the pressure and reduce cycling the air pressure in the tank would need to be increased. But then you would have less water as the tank is already small. So a bigger tank which holds more air and water together is really the only solution.

http://answers.yahoo.com/question/index?qid=20100128134505AAGDhc0

That said we have an 82 gallon tank and an increased line size.

 

[greenhawk]

Depending on the accumulator running over pressure or with large variations can ware them out quite fast. Playing with the counter pressure system is generally a bad thing.

Getting a larger / second unit of similar specs can work better as the pump will not need to turn on / off as often when using water.

not much you can do with the pump besides adjusting the on / off pressure levels.

 

[wirednuts]

my thinking is that this system was never adjusted properly. its only 3 years old... well the pump in the ground is 50 years old, but everything else is updated. it never was right, and im just now trying to make it right for the first time...

 

[Seraphimcaduto]

Yeah I don't think a pump will help you here. Depending on the pumping distance and what not a bigger tank sounds like what you need . To increase the pressure and reduce cycling the air pressure in the tank would need to be increased. But then you would have less water as the tank is already small. So a bigger tank which holds more air and water together is really the only solution.

http://answers.yahoo.com/question/index?qid=20100128134505AAGDhc0

That said we have an 82 gallon tank and an increased line size.

greenhawk is absolutely correct, a larger tank will help stabilize your pressure dropoff. If your tank has a bladder system installed, then that is what is creating the pressure in the water line. Another thing you have to worry about is if you are disinfecting the water in the tank or in the well; if you get another tank, make sure you account for the additional water you are using. If you know how much pressure the first tank can hold, it might be possible to use that as purely a pressure tank and get a much larger tank (w/o a bladder system installed) for water storage right after the tank and this might be the cheaper option. I should mention that I am a Senior Chemist at a water treatment facility and if you have any other questions, feel free to ask.

 

[Micrornd]

A larger tank (with or without bladder) will only make the pump run less, it won't cure the pressure variations in the house, only make them slower to appear.

Your pump run times are about normal for a shower without a water conserving head.

So,first, install a new pressure gauge, so you can make accurate adjustments.

Second, adjust the pressure switch on the pump (even on that old a pump you should be able to set it for 20on 40off, although 30/50 or 40/60 would be better, if the pump is willing).

Third, adjust the air pressure in the bladder tank to 2psi below the cut-on (pump start) pressure.

Fourth, install a water pressure regulator in the line after the bladder tank and before the house, and set it for the cut-on pressure.

This will give you a steady pressure in the house

 

[wirednuts]

A larger tank (with or without bladder) will only make the pump run less, it won't cure the pressure variations in the house, only make them slower to appear.

Your pump run times are about normal for a shower without a water conserving head.

So,first, install a new pressure gauge, so you can make accurate adjustments.

Second, adjust the pressure switch on the pump (even on that old a pump you should be able to set it for 20on 40off, although 30/50 or 40/60 would be better, if the pump is willing).

Third, adjust the air pressure in the bladder tank to 2psi below the cut-on (pump start) pressure.

Fourth, install a water pressure regulator in the line after the bladder tank and before the house, and set it for the cut-on pressure.

This will give you a steady pressure in the house

thank you! this is all exactly what i have planned. its great to get a confirmation step by step though.

funny you say about the water conserving shower head- i do not have one! i used to at my old place, so its easy to tell. in this shower, its like im walking into a monsoon. its way more water then i need at once...

ill probably do all this next week. i have too much other stuff going on right now... and i think ill buy a new shower head too because anything we can do to extend the life of the well pump the better.

 

[Micrornd]

That first line should have read -

"A larger tank (with or without bladder) will only make the pump run less often, but for a longer period when it does run."

 

[wirednuts]

i suspect the start/stop is hard on the pump... but how long do you think the pump can safely run without overheating? of course it will be a guess, but i just want a ballpark. right now it seems to run for about 30 seconds before it cuts off... then rests for a little longer then that..

 

[Micrornd]

If it is a submersible (in-ground, in-well) pump, it can run for several minutes at a time as it is in water and self-cools.
An above ground pump can run as needed but should not be hot (as in not being able to keep your hand on it), warm is ok.

What you want to avoid is short-cycling (on-off-on-off-on-off-on etc.)

While this does not generally hurt the pump itself, (simple AC induction motor hooked to an impeller), it does wear out the starting mechanism (generally contacts and capacitors) and if it goes on long enough it can overheat the pump.

And these days if you wear out that starting mechanism, it is generally used as an excuse to replace the pump (either because the technician is incompetent, as to repairs, lazy, or just sees more profit in a new pump)

 

[wirednuts]

the control contacts are relatively new... its a nice square d relay control.

 

[Micrornd]

the control contacts are relatively new... its a nice square d relay control.

Those too, but I was referring to the ones in the motor, as the motors are usually capacitor aided in starting or running depending on size.

 

[Seraphimcaduto]

A larger tank (with or without bladder) will only make the pump run less, it won't cure the pressure variations in the house, only make them slower to appear.

Your pump run times are about normal for a shower without a water conserving head.

So,first, install a new pressure gauge, so you can make accurate adjustments.

Second, adjust the pressure switch on the pump (even on that old a pump you should be able to set it for 20on 40off, although 30/50 or 40/60 would be better, if the pump is willing).

Third, adjust the air pressure in the bladder tank to 2psi below the cut-on (pump start) pressure.

Fourth, install a water pressure regulator in the line after the bladder tank and before the house, and set it for the cut-on pressure.

This will give you a steady pressure in the house

I'm glad someone understood the desired solution better than I did. Just wanted to apologize for misunderstanding and not answering the actual question.

 

[wirednuts]

Those too, but I was referring to the ones in the motor, as the motors are usually capacitor aided in starting or running depending on size.

capacitor maybe... but i dont think there would be any mechanical contacts down in the ground... and if it does have a capacitor, its surely too old to work.. the lights dim pretty good when it kicks on, and we have a brand new 200a service at this place.

 

[Micrornd]

If on a 200A service the starting of the well dims any lights in the house, YOU NEED AN ELECTRICIAN NOW to check this out.
I can't emphasize that enough, that should never happen, and is a possible cause of fire in the wiring or the electrical panel.
This is no longer about inconvenience but the safety of you and your family.
This is something you should have mentioned first.
Please see to this NOW.

Submersible well pump motors still have a start winding/circuit and contacts, but they are in the control box above ground, while an above ground pump has all that under the end cap or top hat.

That's the reason in residential use an above ground pump motor only has 2 power leads and a ground, while a submersible has either 3 or 4 power leads and a ground.
The starting circuit must be brought all the way up the well to the capacitor(s) in the control box.

 

[wirednuts]

i am an electrician its not a dangerous dim.. it can happen if the lights are on the same bus as the pump is... it happens with a/c compressors too. the circuit breakers are new too, so the risk of fire is low..

 

[Micrornd]

What country are you in?