Direct wiring of PV with pump?

SystemSystem Posts: 2,511 admin
I am wanting to run a water pump (12v, 1.9 amps at 12 volts, 2.5 amps at 13.6 volts, and the pump has a 2.5 amp fuse).

I am looking at a using a 50 watt solar panel.

Can I just wire the solar panel directly to the pump without any kind of power regulation? If the amps from the panels exceed 2.5 amps, I assume I will be blowing fuses?

Any help is appreciated...I'm a newbie to solar panels and know very little about electrical stuff.

Comments

  • System2System2 Posts: 6,290 admin
    Re: Direct wiring of PV with pump?
    Bobby wrote: »
    I am wanting to run a water pump (12v, 1.9 amps at 12 volts, 2.5 amps at 13.6 volts, and the pump has a 2.5 amp fuse).

    I am looking at a using a 50 watt solar panel.

    Can I just wire the solar panel directly to the pump without any kind of power regulation? If the amps from the panels exceed 2.5 amps, I assume I will be blowing fuses?

    Any help is appreciated...I'm a newbie to solar panels and know very little about electrical stuff.

    with a 50 watt panel you probably will be going above 13.6v in full sun so yes, you'd probably be blowing about 1 fuse per day - you may want to get something as simple as a basic linear voltage regulator to make sure your pump doesn't pop fuses every day but they usually have a voltage drop which may mean it won't start as early as it would as if it were direct wired
  • mike95490mike95490 Solar Expert Posts: 8,018 ✭✭✭✭
    Re: Direct wiring of PV with pump?

    On your panel, you should have a sticker, with a bunch of volt and amp numbers, can you post the numbers, or at least the
    Voc number. or even the make/model of the panel

    and the make/model of the pump & its use (deep well, surface transport, pressure building)

    otherwise, we are just guessing. My "guess" is it would work OK, because the pump will load the panel down to where you won't get the peak volts.
    Powerfab top of pole PV mount | 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 ,

  • System2System2 Posts: 6,290 admin
    Re: Direct wiring of PV with pump?

    I'm still in the planning stages, and have not purchased either a pump or a solar panel. However, I was looking at using a Automatic Rule-Mate 500 (bilge pump) for surface pumping....from a spring to a pond.

    As far as the solar panel, I wanted something that coule run the Rule-Mate 500 or, if the Rule-Mate doesn't suffice, some other more powerful pump might might require a little more amperage.
  • mike95490mike95490 Solar Expert Posts: 8,018 ✭✭✭✭
    Re: Direct wiring of PV with pump?

    What is the power draw of the pump ? 30Watts 60 watts 2Amps 13V, 5A12V ???

    More importantly, can your pump lift the water that high ? See what the lift/volume spec is, if volume drops to 1GPH at 34 feet, why bother.

    Archimedes Screw pump comes to mind, for some reason.
    http://en.wikipedia.org/wiki/Archimedes'_screw


    http://www.rule-industries.com/products/pumps/bilge_pumps/rule_500/iid_237/index.htm
    Voltage 12 Vdc 13.6Vdc
    Amp Draw 1.9 amp 2.5A

    Fuse Size 2.5 amp
    Height 3 1/2 inches 89 mm
    Width 2 3/8 Inches 60.3 mm
    Weight 9 oz 260 g
    7 ' lift @ 250GPH

    The problem I see with wireing directly to a panel, is that as the sun rises, the motor will be stalled, and burn out, before you get to 8V where it might start to spin.
    At least it's not a $300 motor.
    Powerfab top of pole PV mount | 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 ,

  • BB.BB. Super Moderators, Administrators Posts: 28,155 admin
    Re: Direct wiring of PV with pump?

    For pumping water, a linear current booster can be a big help (sort of like MPPT for motors)...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,108 ✭✭✭✭
    Re: Direct wiring of PV with pump?

    I am not clear, how high, or how much pressure are you pumping into?
    I don't think that the Rule will push very high, nor into very much pressure.

    There are a number of small cheap pumps that can push into significant pressure. ( As well as some expensive ones)

    Please clarify.

    Icarus
  • System2System2 Posts: 6,290 admin
    Re: Direct wiring of PV with pump?

    The well is going to be hand dug...3 or 4 feet diameter and a maximum of 5 to 6 feet deep. So the pump will only have to lift/push the water 5 or 6 feet to the surface, and will not be emptying into any pressure.
  • mike95490mike95490 Solar Expert Posts: 8,018 ✭✭✭✭
    Re: Direct wiring of PV with pump?

    Try the Rule pump, and if it frys, you are only out $60, and will know you have to buy a linear current booster http://store.solar-electric.com/7amplincurbo.html
    Powerfab top of pole PV mount | 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 ,

  • icarusicarus Solar Expert Posts: 5,108 ✭✭✭✭
    Re: Direct wiring of PV with pump?

    I agree with Mike, try the Rule. I think you could use some kind of voltage controlled switch to start it after you have enough sun. Barring that you could wire in a cheap photo cell adjusted to close only after getting enough sun to run the pump. Another solution would be to buy a tiny motorcycle battery and a very simple charge controller, tie that all to a photo cell or timer. Sun comes up, battery has enough amperage for starting load, panel keeps everything in equalibrium.

    You haven't said how much water you need to pump or for how long. You might have to size any arrangement accordingly.

    Icarus
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Direct wiring of PV with pump?

    WalMart has an Atwood T800 pump that I use for filtration with the above referenced linear current booster

    It will raise the water to 5' or more at 500GPH (800GPH with no head) and it draw about 3.0 amps. I use a 10watt panel and a 5 amp fuse and it works very well.

    The really good news is that the pump is less than $30.00............:D
Sign In or Register to comment.