Looking for pump suggestions for a new well

Discussion in 'Pumps and Tanks Well Forum & Blog. Water is life.' started by Dsperaw, Jul 29, 2021.

  1. Dsperaw

    Dsperaw New Member

    Joined:
    Jul 29, 2021
    Location:
    Colorado
    We just finished drilling our well and am looking for suggestions on our pump and drop pipe.

    Specs:
    440 ft deep
    Producing 5gpm
    Static water is about 250 ft deep
    About 50 ft from house.
    House will be off grid
    Feeds a 5 bedroom house.

    Energy consumption is a concern. We would also like to run the pump off a 4000 watt generator if possible until the house is done.

    Thank you all for your help!
     
  2. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    I am thinking Grundfos 5SQ10-440 or a 5 gpm 3/4 HP pump or a 7gpm 1hp 3-wire pump, preferably with a CSR control box for lower power draw after the start. A normal 2-wire 1hp pump would need a bigger generator. The SQ pumps are normally considered to be easier on generator starts than most pumps.

    This is just an initial idea.
     
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  4. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    The SQ would be a good choice using a generator or off grid. However, I don't think the 5 GPM series will handle 5 bedrooms at peak demand. I think you could still run a 1HP SQ off a 4K genset. Then you could use a 10SQ10-330, which would give you 10+ GPM if needed. With a static level of 250' that would make a back pressure of about 130 PSI, which would work great with a PK1A control kit. Probably go with the 10 gallon size tank having such a large house and using a generator. Could even get the PK1ALT, that does not come with a tank, and supply a 20 to 40 gallon size tank from a local location.
     
  5. Dsperaw

    Dsperaw New Member

    Joined:
    Jul 29, 2021
    Location:
    Colorado
    I don’t think our demand will be as much a normal 5 bedroom. 2 of the bedrooms are for a detached guest cabin.

    I was thinking a 1 horse with a 3000 watt converter transformer. To get 220 of the generator.

    What are your thoughts on the drop pipe? I have a 1” pitless that I was planning to use but I can get 1 1/4” if needed.

     
  6. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    The SQ doesn't need a control box. it is 2 wire and will connect right to the pressure switch in the PK1A.
     
  7. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    I was thinking the 10SQ10-290 would not have enough lift if the well fell to 400 ft. I was picturing the pump at about 400.
    The 10SQ15-330 is 1.5 HP but still may be doable.

    https://www.aquascience.net/downloa...5_330_230v_performance_and_specifications.pdf

    Power input - P1: 2.54 kW
    Operation Via Generator: As a minimum, the generator output must be equal to
    the motor P1[kw] + 10%
    So even with derating required for generators, may be good.

    A step up autotransformer will add more loss. So not sure, but may be OK. Transforming closer to the generator will reduce power loss in the wires.
     
    Last edited: Jul 29, 2021
  8. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    1" pitless and pipe will be fine. The 1HP SQ probably won't be much more than a 3/4HP. At that depth you will need 200 PSI poly pipe.
     
  9. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    The 330 maybe a 1.5HP now. I have an old book that shows it to be a 1HP, 10SQ10 instead of 10SQ15.
     
  10. Dsperaw

    Dsperaw New Member

    Joined:
    Jul 29, 2021
    Location:
    Colorado
    The chart shows the the 10SQ10-330 would still provide 6gpm at 400 which is probably all the well can handle at that depth.

    the transformer will hopefully only be used for a couple months and will be used without any pressure tank to fill up an rv. Once the house is up, I will add the switch and pressure tank. Planning to get the largest tank I can find to minimize startups.
     
  11. Dsperaw

    Dsperaw New Member

    Joined:
    Jul 29, 2021
    Location:
    Colorado
    Do you think poly pipe can handle the pressure? Thought I would need sch80 pvc drop pipe.
     
  12. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Max for 10SQ15 is 239 psi. Actual max pressure seen would be a little less, but you could use 250 psi poly and have extra margin.

    Your well person will be better equipped to use PVC pipe however. You were not going to DIY that, were you?
     
  13. Dsperaw

    Dsperaw New Member

    Joined:
    Jul 29, 2021
    Location:
    Colorado
    Was reading another post here where it was mentioned that the pvc will flex enough to assemble on the ground and drop in in one go. Figured with 4 dudes and a ladder, we could make it work. But poly would definitely be easier. Just want to make sure it won’t burst.

     
  14. Dsperaw

    Dsperaw New Member

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    Jul 29, 2021
    Location:
    Colorado
  15. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    Would be very deep to do with Sch 80 all in one piece. I have done it 200' or so and that is a job. Probably best with 1", 250# poly like was said. Big tank is only needed if you don't have enough batteries to run the pump when needed. 119 gallon tank only only holds 30 gallons of water anyway. Your water comes from the well, not the tank. If you don't have enough power to run the pump you will be out of water.

    A lot of people on solar or generators will use a cistern storage tank. You can fill a few hundred gallons at a time with the generator that way, and even use a smaller pump. Then when the water is in a tank on the surface instead of 2-300' down, even a little 12V RV pump can supply water to some low output devices.

    LOW YIELD WELL_ CENTRIFUGAL_PK1A.jpg
     
  16. VAWellDriller

    VAWellDriller Active Member

    Joined:
    Sep 8, 2012
    Occupation:
    Mud rotary well driller, pump installer
    Location:
    Richmond, VA
    1" pipe and pitless just fine....I think bigger tank and Grundfos 1HP 5GPM SQ may be good fit. Sticking with a 1HP SQ will be the best option for low energy consumption and overall low energy use.

    For comparison I have family of 4 with a 5SQ feeding my house...we've never had a problem with peak demand...to handle little demand spikes I have 40 gallon tank, precharge to 38, CSV set at 65, switch at 50/70. I think we may drop under 50 every now and then , but nobody knows it but me. If you have space, you could put in a 86 or 119 tank leave precharge little lower than normal and switch a little higher and you'd have plenty of water.
     
  17. Dsperaw

    Dsperaw New Member

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    Jul 29, 2021
    Location:
    Colorado
    What’s the deal with a dole valve? Is a valve like this needed?
     
  18. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    Although a larger pressure tank with a low air pre-charge will give a few gallons extra during peak demands, it won't help but for a minute or so. The 5SQ pump will most likely handle the job fine, I just don't like to see dips in pressure because of a little extra demand. I would still use the 10SQ-380, and not have any dips in pressure as it will supply plenty of water.

    A 5 GPM Dole valve would limit the output of the pump to 5 GPM. This would keep you from ever pumping the well dry, but won't let you have anymore than 5 GPM for peak demands. With the pump set at 400' and the static at 250', you have 225 gallons stored in the well to use as fast as you need. A 10 GPM pump can supply 10 GPM for up to 20 minutes before the well runs dry. This can handle peak demands better than a larger pressure tank with a low air charge. The SQ has a built in control box with dry well protection. So, if you do run 10 GPM for more than 20 minutes the pump will shut off. I prefer the way a Cycle Sensor protects the pump from running dry, but the built in feature of the SQ works fairly well.

    One of the good things about controlling it with a Cycle Stop Valve is that the CSV works like a variable Dole valve. As long as you don't use more than 5 GPM, the CSV will act like a 5 GPM Dole valve and not let the well be pumped dry or destroy the pump. But when you need more than 5 GPM for peak demands, the CSV will give you as much water as you are using, so there are no dips in pressure.
     
  19. Dsperaw

    Dsperaw New Member

    Joined:
    Jul 29, 2021
    Location:
    Colorado
    Does anyone know what the difference between the 10sq10-380 and the 10sq10-290 is? Or if there is any?
    I can’t find the 380 anywhere.

    https://www.aquascience.net/grundfo...0143-3-stainless-steel-submersible-well-pumps

     
  20. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    To use pump curves, there are three parts that make up the head the pump sees: Actual altitude change, dynamic head(friction), and pressure head. Dynamic head is fairly small. Maybe add 10 ft estimate, which is probably high. 60 psi is 138.39 ft. I usually use 140 for easy figuring. And the altitude is the altitude difference between the pressure switch and the surface of the water. I am thinking you would want some flow with 500 ft of head, which would correspond to the water being at about 360 ft. Originally I was targeting 400 ft, but if you want a 10 gpm SQ pump, you can't do that. If you want to pump from 400, you need a 5SQ rather than a 10SQ. The 5SQ will be easier on your generator and could work deeper if needed.

    If the water falls down as far as it will go, you would like the pump to deliver at least 1 gpm of water. Normally the water level is higher. You don't want the pump to pump more than maybe 1.8 times the nominal pump rating when the water is at the static level. I am unsure of this number which I chose arbitrarily. This avoids upthrust.

    The pump you choose should be one that is available.


    img_sq5.png img_sq10.png
     
    Last edited: Jul 30, 2021
  21. Bannerman

    Bannerman Well-Known Member

    Joined:
    Mar 19, 2014
    Location:
    Ontario, Canada
    To clarify, 60 psi = 138.39 feet of head.
     
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