Issue with AC and DC Pumps off Solar Electrical system

[rowellc]

Hi:

I have had issues with my water system ever since I installed solar. Electricity is fine and all radios, tv's, lights all are working.

I had a shurflo DC pump which I bought from New England Solar in Mass. My plumber installed it but it kept coming on every other minute or so every time
we turned on the water. I have two 900 gallon water wells on a hill which flow
down hill to the place I have. I have a basement and had gravity feed so I thought
no issue, just install the Shurflo DC pump. with my Rinnai Gas water heater and should have no issues. The pump kept coming on every other minute, so my plumber suggested I get a new Jet pump instead. I called New England Solar and
they said no problem your Inverter should be able to handle it without any issues.
Sure enough the AC jet pump comes on every other minute just like the DC pump.
It loses its prime and my plumber is perplexed. So now I have a jet pump which loses it prime.

Here is what my plumber is saying (the loser!!!!!!)
The symptom that the pump is showing is similar to a tank with more pressure than the switch calls for. I checked the tank pressure yesterday because it should be 2 pounds lower than the cut-in pressure of the pump. The pressure is 18 pounds so that is not the problem – you might want to tell the next plumber that. When I turned on the power the pump was primed. You get water and pressure in the house but the pump continually turns on and off. I was going to bring in another plumber today but then saw your email last night. It’s understandable that you want the problem solved quickly and you are right to get another plumber. I’m sure he’ll be able to work it out for you. Please send me your mailing address so I can bill you for the last few hours.

Any of you SOLAR GURU'S have an idea what may be going on?
I have an Inverter and it appears to work correctly. 6 Trojan 105 batteries.
It sounds like the Plumber just does not know what he is doing. I just can not
tell what the issue is? ANY IDEAS or any SOLUTIONS WOULD BE GRATEFULLY ACCEPTED.

Charles Rowell

[mike90045]

Maybe try setting the water pressure switch to a wider setting,
On at 18 psi, Off at 50 psi.

Also check for a waterlogged pressure tank, and an oversized pump. 18 psi seem a bit low. Oversize pump fills the tank too fast. waterlogged tank has very little airspace to store pressure.

[niel]

now i can't say i may know the answer to your problem, but i'm having difficulty knowing if the pump is feeding these tanks or is it to pressurize your home lines. if it is feeding the tanks to pressurize your home lines then that isn't good in my opinion. clarify it for these guys that have more knowledge and experience with pumps than i do.

[rowellc]

Originally Posted by niel

now i can't say i may know the answer to your problem, but i'm having difficulty knowing if the pump is feeding these tanks or is it to pressurize your home lines. if it is feeding the tanks to pressurize your home lines then that isn't good in my opinion. clarify it for these guys that have more knowledge and experience with pumps than i do.

I have a TRACE DR2412 2400 WATTS 12 Volt system.
These TRACE INVERTERS are fully capable of powering an alterative energy household. THE DR2412 can be used for a deep well pump. It will run a correctly
chosen submersible pump or jetpump or DC pump. I have 6 TROJAN 105 batteries
about two years old. Everything is charging correctly. Output voltage 12O VAC
280 Amps Input. Waveform Modified Sine Wave. So I had a DC pump coming on
every other minute and now a AC jetpump coming on every other minute. I think
the Plumber is the issue. Could this be a Solar Power electrical system issue?

What I have are two wells each store 900 gallons of water. They are built up on a Spring on a hill that is about 8 feet above where my basement is. I have attached a water line to both of these two wells and the water flows down to the
house about 800 feet or so at which point it enters to basement where a jetpump
and tank reside. I have gravity feed from both of these wells but not enough water pressure to run up to the first floor of the house, which is why I need a shurflo pump or jetpump to pump the water up 10 feet to the first floor.

I am trying to get the jetpump to fill up the water tank which is about 8 to 10 gallons without coming on all the time which it does every time I turn the water on. The pump and tank are brand new so I doubt the new tank is water logged.

I just can not tell if it is the solar power system causing this issue or is it the pressure in the water tank or lack thereof... As both the DC pump (Shurflo) and the new AC Jetpump are having the same issues, it is either the Solar Power, or the other common denomimator is the Plumber. I have gotten rid of the Plumber
and am getting another Plumber but what about the Solar. Both runs are coming
on ok.

I kind of think it may be because my plumber does not know how to configure a jetpump or a DC pump for that matter, but I was just wondering if anyone has had a similar issue with their solar power system as well. I have 6 trojan batteries
and an Inverter. New England Solar felt it could easily run either pump. So I am at a loss to explain what is going on.

Charles Rowell

[mike90045]

A 10 gallon pressure tank is WAY TOO SMALL. Those small tanks need a special pump to run them. Standard size tank is about 30 gallon, and up. I think your pump is way too big, and fills the tank too quickly. And small tank empties too fast, and pump comes back on.

[Cariboocoot]

Get yourself a new plumber. Or better yet, become your own plumber.

Pumps turn on because the pressure switch turns them on. They don't care what the source of power is. The power source might cause them to turn off due to insufficient power, however. So if the pump comes on, the power drops to inadequate, the pump shuts down, the power level comes back up, the cycle repeats.

I don't think this is your problem, as one way or another the pump will eventually fill the pressure tank and then that must be drawn down below the 'on' pressure before the pump activates again, regardless of power.

So what does the pressure gauge read? Tell me there's a pressure gauge! You should be able to get distinct results by watching the gauge and opening a tap: pressure drops below 20 psi, pump comes on. Close tap: pressure builds to 50 psi, pump turns off. If it behaves other than this (pressure settings might be different but 20 to 50 is pretty much a normal operating range) please report the results back.

One other thing: put a tire gauge on the bladder of your pressure tank. It should be set 2 psi below the pump's 'on' pressure.

[Cariboocoot]

Originally Posted by mike90045

A 10 gallon pressure tank is WAY TOO SMALL. Those small tanks need a special pump to run them. Standard size tank is about 30 gallon, and up. I think your pump is way too big, and fills the tank too quickly. And small tank empties too fast, and pump comes back on.

I missed that tank size info. Mike is 100% correct about this. At least 20 gallon! Bigger is better for pressure tanks; reduces pump cycling.

[icarus]

Your problem is most certainly in the plumbing, not the power system. As has been suggested, be your own plumber or find one who knows something other than conventional well pump systems.

If you have gravity feed into the house, you should only need a tiny little pump to pressurize your P-tank system. I second (or treble) the note about not enough tank. Tiny tanks lead to rapid cycling. Also, pumps generally like to "push" water better than "pull" water.

If I understand you basic system correctly (which I may not) you have gavity to the house. I would plumb the intake to the pump (making sure that line from the gravity tanks is big enough, given the distance, at least 3/4" and ideally 1 or 1 1/2 if it is a long run with lots of elbow or other restrictions). I would then run it into at least a 50 gal P-tank. (A 50 gal tank will deliver ~30 gallons of water) I would set the tank 20-40 or perhaps 30-50 psi. The extra pressure won't make any difference in the "feel" or volume of water, nor will it deliver much more water without the pump cycling, and it takes significantly more power to pump that last 10 psi.

Tony

PS I personally would only install a bladder tank. They never get water logged, you never introduce air to the water system. To use any other type of tank is like trying to drive the Indy in a Model A.

PPS Your demand water heater will perform much better once you get the water pressure stabilized.

PPPS If you have gravity feed, I think the ac jet pump is way more pump than you need, and it therefore may not be a very efficient installation. I have run single cabin systems on tiny little shurflo pressure pumps, that draw as little as ~5 amps, drawing water out of the lake, lifting it ~15' and pumping it into 20-30 psi.

I'll stop now.
t

[blackswan555]

A big pressure storage tank is better all round for pump , Batts & inverter (1 long pump run as opposed to lots of little ones) But from your description I would have a look at your plumbers use and placement of non return valves (and are they the correct way round)

Tim

[rowellc]

Originally Posted by blackswan555

A big pressure storage tank is better all round for pump , Batts & inverter (1 long pump run as opposed to lots of little ones) But from your description I would have a look at your plumbers use and placement of non return valves (and are they the correct way round)

Tim

Appreciate the info. I am not a Plumber but what is a non return valve?

Charles