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  • New water pump for pressure tanks

    We have a full time off grid home with a 500' deep well. Currently we have a soft start Grundfos 5SQ-410 pump that runs at 6.6 gallons per minute into three pressure tanks for a total of 98 pressurize gallons . It takes just over 15 minutes of running to pressurize the house at 30/50# of pressure. The problem is the well pump comes on at night which really hammers our batteries. The current well pump draws 11.2 amps and shows about 2.5 kw while running. I'm thinking of going to a 1000 gallon cistern with a smaller pressure pump so that it can run at night if needed. I will have the solar to use the well pump during the day to pump into the cistern. By the way, our household uses 230-260 gallons of water per day and our elevation is 8,600'. The options I have are as follows: 1)I've found a Grundfos JP05D-CI jet pump that is 1/2 hp and is rated at 3.61 amps at 115v or 7.06 amps at 230v that pumps at 12.5 gallons per minute and uses about 770 watts while running. It is not a soft start pump but will pump up my 98 gallon pressurized tanks in just under 8 minutes which will save some power.
    Option 2) is a Grundfos scala2 "on demand" pressure pump that would not need the pressure tanks I currently have in place. It would power up every time you open a water valve or flush a toilet. This pump can be plugged into a 115v outlet and uses 5.7 amps and pumps at a rate of 13 gpm and uses about 550 watts while running. It has a variable smart control that "learns" your plumbing to control speed and power necessary to maintain a pressure you select up to 60#.
    There is also the possibility of a 1/2 hp 150' well pump from China that will do the trick of pressurizing my pressure tanks and will just lay down in the cistern. These can be wired either 115v or 230v and pump up to 25gpm.
    So, my question is which of these three alternative would offer the least impact on the health of my battery bank? Or do you have a recommendation for a pump or setup that will reduce my battery usage in the evenings?
    Thanks for any info you are willing to share.
    Last edited by Mike90250; 12-31-2017, 09:46 PM.

  • #2
    I cant recommend a pump,

    Do you have any elevation close to the house?

    if you can get a tank 65ft above the house this will give you reasonable gravity feed pressure.

    Pump to the header tank when sun is good, this is the best option if available as you use no power for water at night.

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    • #3
      Originally posted by Bala View Post
      I cant recommend a pump,

      Do you have any elevation close to the house?

      if you can get a tank 65ft above the house this will give you reasonable gravity feed pressure.

      Pump to the header tank when sun is good, this is the best option if available as you use no power for water at night.
      Thank you for that recommendation. I'm nearly to the highest point of my property and the only part that is slightly higher is about 80 feet away and then it's only about 20-25' above my garage, so that unfortunately won't work. I didn't consider that when I was building so had I built lower down the hill, I could have done that. Too late now though.
      Happy New Year!

      Comment


      • #4
        i was also playing with solar water pumping. several ideas you maybe allready refused, maybe not.

        1 - consider cascading system - not pumping all the head at once, but using smaller pumps (12v or 24v) in several stages meter by meter. based on my experience with power consumption vs head of pumped water vs price of pumps fewer smaller pumps can make the difference. another plus, at least this will remove looses connected with DC/AC conversion... also based on your problem - running from batteries, its in general better to take lower ampere for longer time, than higher ampere for short time, even if the summary amperhours is the same. depends on battery types, age, specifications...

        2 - if you have enough water and you are not concerned about loosing or redirecting majority of that water elsewhere - think about system like a ram-pump, consider implementing into cascade... partially of course. this will pump the water without electricity, whic may help you to manage the process by the way, when during the day pumps will run and at the night rampump... several possibilities, combinations...

        both choices will require some countings and googling, comparing of different products and connecting them together. at the end of the day im sure it could be more effective in the meaning of battery savings... everything depends on when, where and how much water you need. managing these 3 conditions could do it...

        Comment


        • #5
          Originally posted by racmaster View Post
          i was also playing with solar water pumping. several ideas you maybe allready refused, maybe not.

          1 - consider cascading system - not pumping all the head at once, but using smaller pumps (12v or 24v) in several stages meter by meter. based on my experience with power consumption vs head of pumped water vs price of pumps fewer smaller pumps can make the difference. another plus, at least this will remove looses connected with DC/AC conversion... also based on your problem - running from batteries, its in general better to take lower ampere for longer time, than higher ampere for short time, even if the summary amperhours is the same. depends on battery types, age, specifications...

          2 - if you have enough water and you are not concerned about loosing or redirecting majority of that water elsewhere - think about system like a ram-pump, consider implementing into cascade... partially of course. this will pump the water without electricity, whic may help you to manage the process by the way, when during the day pumps will run and at the night rampump... several possibilities, combinations...

          both choices will require some countings and googling, comparing of different products and connecting them together. at the end of the day im sure it could be more effective in the meaning of battery savings... everything depends on when, where and how much water you need. managing these 3 conditions could do it...
          Hey, thanks for the suggestions. I have been looking at the ram pumps. Just don't know if they will provide the necessary pressure for the house. Looks like a great idea if you have a stream, pond or lake nearby. Our creek is about 300' below our house and 600 yards away. The cascade idea would have merit if I could get the water to a higher elevation then allow it to drop down into the house, but my house is pretty much at the highest point on our rise. Still looking into how that ram pump might fit. Thanks again.

          Comment


          • #6
            Ram pumps use [B]lots [/B]of water to pump a little bit to a higher elevation. So if you have water to waste, they are good.
            Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
            || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
            || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

            solar: http://tinyurl.com/LMR-Solar
            gen: http://tinyurl.com/LMR-Lister

            Comment


            • #7
              Originally posted by Mike90250 View Post
              Ram pumps use [B]lots [/B]of water to pump a little bit to a higher elevation. So if you have water to waste, they are good.
              Thanks for that. Doesn't sound like it will work for my application.

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              • #8
                Do you have room for more pressure tanks? It might be simpler to do that than put a cistern/booster pump in. You could also set a timer and second pressure switch so it pressurizes the system in the day time. Then runs at a lower pressure just as needed at night.


                I don't have much experience with battery systems so I can't be much help as to that aspect.

                Comment


                • #9
                  Originally posted by bwkemp View Post
                  Do you have room for more pressure tanks? It might be simpler to do that than put a cistern/booster pump in. You could also set a timer and second pressure switch so it pressurizes the system in the day time. Then runs at a lower pressure just as needed at night.


                  I don't have much experience with battery systems so I can't be much help as to that aspect.
                  I have considered that. I would have a space problem in that part of the garage, but think it would be doable. Based on what I currently have, I could add another 30-35 gallons of pressurized water. What I hope to gain from putting in a cistern is the ability to bank water so that I could be certain to only run the bigger well pump during days with full solar. This past fall has been a lot different than what we've had in the past eight years. Practically every other day we have clouds significant enough to reduce my solar generation to half so that absorb or float cycles are not reached, so pumping any water with that well pump is not the best thing. Then comes the snow cycles that will last for 2-3 days, where solar gain is almost nothing. If I can bank enough water, I won't have to run the well pump during this time which will save us lots of load on the batteries. So, ideally, if I can find a pressure pump that will reduce my energy used by the main well pump by 1/4, that would be great.

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                  • #10
                    There are many 12V marine and RV pressure pumps, that give a decent shower. Should be some 24V offerings too. But getting the water UP from down below, to above ground tanks or whatever, will reduce a lot of your night time usage. I foresaw the nighttime water issue, and have nearly 1,000 ' of pipe and wiring, up a hill for gravity feed tanks. I had to put in a household fire sprinkler system. which needed a huge flow rate to pass inspection. (apparently smoke alarms are not enough in kalifornia, household sprinklers required in 2012)

                    https://www.westmarine.com/buy/shurf...67?recordNum=7

                    24V 5A 55psi 4gpm

                    Even a 20 gal tank in the attic would give enough pressure to refill a toilet tank in 5 minutes. Do you have freezing temps in your attic ?
                    Last edited by Mike90250; 01-02-2018, 12:05 AM.
                    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                    solar: http://tinyurl.com/LMR-Solar
                    gen: http://tinyurl.com/LMR-Lister

                    Comment


                    • #11
                      i was thinking about a loop, where on the begining will be a circulating pump, which is very effective and low power needed. the problem with circulation pump is, that it neeeds tha water pushed uphill to go back and turn around, and exactly this is the point where ram pump helps. tha waste water from the ram pump on stage 2 will come back into circulation pump on stage 1 with some buffer of the size exact same or bigger as the amount of rampumped water... during days - solar power-days, buffer tank will be fullfiled by strong pump, during night, rampump and highly effective circulation pump will slowly but continuously cumulate water uphill at very low wattage...

                      as soon as the water will be there - in the house, do not use the pressurized tanks and pressure pumps, which fights the counterpressure of the tanks and therefore takes a lot more power. use self priming pumps, 12/24v power effective pumps with just much enough flowrate and pressurate... for few dollars you can install one for every tap, if you really need so much pressure and flow...

                      next suggestion to use or combine with previous - buble pumps. pumping air is much lighter and also provides some water intake uphill. also a solution for low power days/nights.

                      in general, there is nothing else or easier to do. the energy needed to elevate the weight of water against gravitation must be spent. only question is effectivity of the system used... there is a rule - less human power invested, more electricity needed to compensate and vice-versa.

                      next and only possibility is to simply increase the pv/battery system and just install big enough pump... which is not intended as i understand...

                      Comment


                      • #12
                        There are number of pumps available but your second alternative would we better than except pumps after attain of Grundfos JP05D-CI jet pump that contain, half of hp and is rated at 3.61 amps at 115v or 7.06 amps at 230v that pumps at 12.5 gallons consistent with minute and uses about 770 watts at the same time as running. It is not a smooth start pump however will pump up my 98 gallon pressurized tanks in only underneath take seven or eight minutes in an effort to store some energy.I don't have much experience with battery systems so I can't be much help as to that aspect.

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