Waterfurnace submersible pump connection (open Loop)

Discussion in 'Open Loop' started by ES - Stoneham MA, Feb 16, 2015.

  1. ES - Stoneham MA

    ES - Stoneham MA New Member

    I noticed in the waterfurnace series 7 manual that there connections for the pump. Has anyone done this before?

    What i'm trying to do is meter the pump usage. and before exploring other 230V power meter, i'm trying to see if anyone has the open loop submersible pump connected to the waterfurnace.

    My pump is Goulds 18G07 - 3/4 HP.
  2. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    I believe that board is only 1/2 HP rated.

    Another thing to keep in mind is how much that 3/4HP will be running with a WF-7 series.
  3. ES - Stoneham MA

    ES - Stoneham MA New Member

    I'm planning to reduce the pump to 1/2 HP. I also use the well/pump exclusively for my geothermal setup. Do you have it installed?
  4. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    I have installed well pumps off the units. Not the current 7 though (yet).

    The WF 7 series has long expected run times as it gears to match building loads. I don't know your particular demands. Figure out the energy use of that well pump. You are going to eat in to your geo savings with it running a lot.

    edit: Look for a variable speed 1/2 hp.
  5. ES - Stoneham MA

    ES - Stoneham MA New Member

    Chris, thank for you feedback. I would really appreciate your feedback on this.

    here is my situation:

    Moved into a new house in Dec 2014 and have installed the following:
    - Waterfurnace series 7, NVV060, 5 ton with Intellizone 2 with 3 zones
    - I have an open loop. The well is 605' deep. pump at 140', water table at 20', incoming water temp is currently at 50 degrees and exiting around 45
    - Pump is Goulds 18GS07 . 18 GPM and peaks at 26 GPM
    - Controller is CentriPro Model CB07412, HP3/4, V 230, 7.2 AMP,
    - New construction House is 2 storey colonial about 3700SF, HERS rated at 33. all LED bulbs and high efficiency appliances. R28 Walls, great insulation and air tight
    - HRV
    • Solenoid valve is set at 90% opening making the flow at 26 GPM.
    Here is my issue, after running the system for a month, its awesome and we love it until i got the electrical bill. From a Waterfrunace perspective, the thermostat does energy consumption and is recording that i used 838kW in Jan. Which is averaging about 28 kW per day. No issues there, I only had electrical aux heat kickin for 30 minutes the whole month, based thermostat display. The house consumption for the month was 2700kW. So where is the whole draw coming from? I called my electrician and he brought his probe:
    • Geo is using about 5 to 11 amps
    • Pump using around 7 amps (consistent)
    • I forced the geo to go into electrical aux, and it was using 50 to 65 amps (which is expected)
    • based on my simple calculations (7 amps * 230V = 1.6kW/hour. geo runs for 20 hours/day = 32 kW per day x 30 days = 966 kW), the pump is consuming as much power as the geo during the month. The Geo used 838 kW in Jan for geo, the pump is using more. which is really crazy!!!!
    • Considering how Cold Jan was what the geo consumed sounded reasonable and within the estimates that was provided by the geo installer
    • the electrician measured the power at the panel incoming wires, and it registered 17.5 AMP. (inside the house). the pump and geo were running.
    My geo installer suggested to replace the pump with a variable speed pump and controller/drive, but did not recommend any and mentioned that he does not sell them either.

    My pump dealer, (GOULDS), has no idea on how to make the pump work with the variable speed control constant pressure. He recommends just replacing CentriPro Model CB07412 with 1AS15 and should solve my issue. Since I did not trust him, I call Gould technical support and they recommended:
    • reduce the size of the pump to 13GS05 pump (1/2 HP, and 3 phase)
    • M07432 motor, ¾ HP
    • 3AS20 VFD (1 phase input 3 phase output 3 phase)
    • Pressure set to 40 psi to provide 10gpm

    My Pump installer claims that Goulds technical support don't know what they are talking about. I'm not sure what to do?
  6. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    O.K. This can be sorted. But I'm stepping out for the day.

    Other experts on this forum deal with open loop pumping as well, and they may chime in.
  7. ES - Stoneham MA

    ES - Stoneham MA New Member

    I would really appreciate any help as I'm truly lost here. here are the well/pump specs
    • Depth: 605'
    • well static 29' from grade,
    • an additional 22' to house (not sure what this means)
    • 18gs07412 Goulds Submersible
    • recovery 3gpm
  8. ChrisJ

    ChrisJ Active Member Forum Leader

    I am not a pro, just a homeowner.

    Is that recovery correct? Only 3 gallons per minute! And your pumping 26 gallons per minute.

    Must be a typo.

  9. ES - Stoneham MA

    ES - Stoneham MA New Member

    Its dumps the water back in the well.
  10. pfer10

    pfer10 Member

    Static is your water level in the well. It sounds like you will have 29' + an additional 22' of head just pumping up to the house at no pressure. Do you have any idea what size line you have from the well? How far is the well from the house? You say you only use the well for the Geo? So it pumps to the Geo and then drains straight back to the well? For your Geo you should only need 15 GPM max.
  11. ES - Stoneham MA

    ES - Stoneham MA New Member

    Yes, the water drains back to the well. The pipe to the house are 100', the pipe size is 2". well is for exclusive use for Geo.

    Couple of question, at what level should the water be return at? or what the is the distance where the pump is placed vs the location of drained water?
  12. pfer10

    pfer10 Member

  13. ES - Stoneham MA

    ES - Stoneham MA New Member

    is there a particular thread that you are referencing?

    what is the difference between SCW and Open Loop?
  14. ChrisJ

    ChrisJ Active Member Forum Leader

    SCW is a type of open loop that returns the water to the same well.

    Blake Clark came up with a SCW system that uses the vacuum of the water traveling back down the return water pipe.


    Also has posts at greenbuildingtalk forum.


    He admits he went through a lot of trial and error, but he achieved some good results. Very technical stuff.

  15. ES - Stoneham MA

    ES - Stoneham MA New Member

    thanks again chris.

    what are you thoughts on recommendations? any opinions would be appreciated.
  16. ChrisJ

    ChrisJ Active Member Forum Leader

    Like I said I am just a home owner, just trying to point you towards info I thought might help.

    Quote from Blake:"If I'd had a near-surface water table (wouldn't that have been nice!) I would have gone with a Grundfos 22SQE-40."

    That is in one of the threads I linked.

  17. ES - Stoneham MA

    ES - Stoneham MA New Member

    Thanks Chris. they are a very interesting ideas.

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