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Solar pump / charge controller wiring question

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  • Solar pump / charge controller wiring question

    I have a small off grid cabin that is a weekend getaway. My current system is 4 200w 50v sanyo panels on a T.O.P. mount feeding an outback flexmax 60 controller to 4 T-105 Trojans w/ a 2k Prosine inverter. My batteries are parallel series for 12v and the panels are parallel for 50v to the charge controller. I was advised not to run the panels series parallel to the charge controller as it may over volt the controller under extreme conditions. Grundfos says that the pump will run at 50vdc it 's optimum efficiency is at 120vdc. I'm thinking about getting a 4 pole/dual throw switch and wiring it as follows.

    2x (two panels in parallel at 50v to two poles on the switch) (50 ' away) giving me 2+ and 2- at 50v at the line in on the switch. I'd wire the + to+ and - to- to the controller. That's the easy side.

    For the pump side I think I'd wire + to pump, + to - , -to pump. That should run the 2 parallel pairs in series for 100vdc. I'm running 10ga wire from the panels and would have to pull the positive buss out of the combiner box and separate the positives and negatives, and then pull an extra pair to the switch. With the switch 50 ft from the panels I guess there would be 200' of wire in the series circuit. Is this going to be a problem?

    I have a single breaker before the charge controller and would add another and wire them before the switch basically as a PV power shut off in the power shed. It's another 100 ft to the well and 270' down the hole so the higher voltage should help with the distance (works great with 120vac). Have a 2600gal storage tank uphill so I pump when I'm there. Would like to automate the system in the future with a timer so the overflow waters the garden and fills the pond. 4 Relays? If you made it this far, thanks for hanging with me. Any input is appreciated
    p p
    u u
    m m
    p l<<l p
    + - + -
    + \ + /
    + \ + /
    + \+ /
    + + \ \
    CC+ CC-

  • #2
    ? ASCII art, does not work well with kerning fonts. If that's what you were trying at the end.

    I think I've built the system you describe somewhat. I've got my 240V pump, that is controlled by a CONTACTOR (designed for a well pump). Contactors are really beefy relays. The enable coil for the contactor goes through both a intermatic timer (old clock motor and gears, and cams that trip a switch on & off) and a float switch at the tank. Timer enables the pump to run 10am - 2pm, while the sun is mostly out, and so the batteries only stabilize the power, but mostly,m the pump is powered by the sun, and does not drain the batteries.

    And it's good you consider the length of the total electric wire run to the pump, some wells are pretty deep !
    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