Solar well pump on / off control



  • Solar2Solar2 Registered Users Posts: 30 ✭✭
    Interesting Thread,
    A few comments and thoughts;

    Save yourself the problems of using pressure switches.
    The problem is not the switch sensing small differentials.
    Anytime you start/stop a pump on a long line, or some one flushes a toilet etc., you set up traveling pressure waves.
    A switch based system 90% of the time will end up with short cycling problems.

    Years ago I had the responsibility of a large campus with several water towers.
    They were using small differential pressure switches with long mechanical delays to control pumps.
    We needed to sense a foot of water pressure in a 100 ft tower.
    The switches would do it but we had continual problems like the setting for summer would not work in the winter
    And the delays were a continuing problem.

    Anawa has a valid point, the wireless links are not going to solve your problem.
    Buried lines have the same problem of what to do with the two receiver tanks at different elevations.
    Buried lines are no fun to install in mountainous areas.
    It can be done however.  
    A 40,000 lb bulldozer with vibrating shank will knife wire through solid rock.
    It will not be in conduit but you don't really need conduit when you are in rock and use the correct cable.

    Lightning is seldom a problem with buried lines.
    Lightning is mostly RF power.
    The characteristic impedance of a buried line is way off what it needs to be to transmit lightning generated RF.
    Plus, most wire now days is PVC insulated.
    PVC has a significant absorption coefficient for RF.

    All in all, the float valve method seems to be the best choice.
    Make sure to have a good check valve at the pump and between the two elevated tanks.
    This along with a delay before start, or as you suggested, require a manual start should work.
    I would size down the pump such that it would not greatly over pressure the system when pumping against closed valves.
    Looks like your are at or above the max pressure rating of standard PVC pipe.

    18 Kw PV;  2000 AHr FLA Bat; 12 Kw Inverter;  20 Kw Kohler, LP, low speed, double muffled,   Home built, ground coupled heat pump, VFD enabled;  Leaf
  • Eric_REric_R Registered Users Posts: 13 ✭✭
    The system is in! Check it out.

    It has been running flawlessly for 3 months now.

    What do you think?


    Part 1

    Part 2

    Part 3
  • AnawaAnawa Solar Expert Posts: 211 ✭✭✭
    Eric, looks like you did a very good job engineering your system. Thanks for the update and good luck with "keepin er' up and running!"
    in Georgia

    System 1: PV- 410w Evergreen, Mppt- Blue Sky Solar Boost, Batt - 225ah Deka AGM, 12v led house lighting,
    System 2: PV- 215w Kyocera, PWM - Morningstar PS30, Batt- 225ah Deka GC's, 12v led house lighting, Dankoff 12v water pump,
    System 3: PV- 1.5kw Kyocera, Grundfos 11 SQF well pump, 3000 gal above ground water storage, dom water & irrigation,
    System 4: PV- 6.1kw Kyocera, Mppt- Outback FM80-2ea, Inverter- Outback FX3648-2ea, Batt- 804ah GB traction, Grundfos BMQE booster pump 240v, Mitsibushi mini-splits 240v, 18k and 15k
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