12 volt deep well pump question suggestions

joe cannonjoe cannon Registered Users Posts: 6
I have an 1-1/4 well that is about 40 feet deep and am currently using a shurflow 12 volt 8000 series pump that delivers about 1 gal a minute.
I would like to get that up to 2 gallons a min.
I have a solar array that produces 220 watts @ 12 volts.

I used what I had on hand to build a controller ..morning star pro star 30 charge controller, 2 6 volt golf cart batteries.

I also wired up a small solar panel (they type VW uses to keep the battery in cars charged during shipping) to a relay, placed in a location that does not get sun before the main array is in full sun and it goes into shade 30 minutes or so before the main array does. That has been keeping the Battery bank fully charged..

I know that 40 feet of lift is extreme.. but any ideas? Thanks

Comments

  • BB.BB. Super Moderators, Administrators Posts: 30,946 admin
    Re: 12 volt deep well pump question suggestions

    Are you pumping to a cistern/tank/holding pond or is this to a pressure tank/home water system?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • joe cannonjoe cannon Registered Users Posts: 6
    Re: 12 volt deep well pump question suggestions

    No it is just used for irrigation , connected to a garden hose...with nothing on the end (no back pressure)
  • BB.BB. Super Moderators, Administrators Posts: 30,946 admin
    Re: 12 volt deep well pump question suggestions

    Then designing a system with a solar array, linear current booster, and DC pump might work out better...
    Used to control and power a DC motor from a solar panel. The unit prevents stalling of the motor under less than full sun condition. The power of the sun is transformed to the motor running conditions so as the sun goes down the motor slows down instead of stalling. Conversely, or as the sun comes up the motor starts running much earlier instead of staying stalled for hours when it could be running. This translates into more running time of the motor where it spends a lot of time working instead of stalled doing no work.

    This unit is suitable for such pumps as the Shurflo 8000 and 2088 series, where you do not need all the features and capacity of a full blown heavy duty pump driver.

    Adding a battery and charge controller will make the system almost 4x the cost (battery+replacement+controllers to prevent taking a battery dead, plus battery losses) as running a straight solar to pump system without the batteries in-between.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 12 volt deep well pump question suggestions

    Welcome to the forum.

    I have to say I'm surprised you're getting anything with that pump and a 40 foot well (which technically is not classified as "deep" by standards). They really aren't designed for that kind of lift.

    You could change the pump for a higher capacity one (the 2088 perhaps) or double up the pump with another of the same type.

    The "1 1/4 well" sounds like a "sand point" to me. :roll: That eliminates the submersible pumps entirely (it's a lot easier to push water up than to suck it up).

    There are many DC powered pumps available, including some that run "directly" from solar panels. As always they cost money. Sometimes lots of money.

    Probably the cheapest solution would be to add a second 8000 pump in parallel with the existing one (both controlled off the same switching so they function as one). Just make sure the piping is large enough to accommodate input and output (only narrow down at the pumps).

    This will draw more power, of course. So you will have a higher flow rate but won't be able to power it as long.

    I take it the VW panel & relay is to prevent the pump from coming on before full sun is on the main panels? The Prostar 30's LOAD terminals can handle up to 30 Amps. You could run the pump(s) from them and have the water available whenever battery Voltage is above LVD set point. The Shurflo 8000 draws <8 Amps at maximum pressure. Furthermore, I believe the PS30 will shut off loads when there's no light on the panel (nighttime operation).
  • joe cannonjoe cannon Registered Users Posts: 6
    Re: 12 volt deep well pump question suggestions

    I also use the solar system to run my Ham radio gear and in emergency lights and a 1200 watt inverter...also in the battery bank is 2 yellow top optima batteries that are in bank 2 (not used until needed,just topped off once a week)
  • joe cannonjoe cannon Registered Users Posts: 6
    Re: 12 volt deep well pump question suggestions

    I do run the pump off the The Prostar 30's LOAD terminal..but added the relay and the triggering panel to make sure the battery bank stays fully charged so that I can use it at night for other things like my ham radio gear.
    Yes and I was surprised that the pump worked at all at that depth ..It is not rated to do so.. but it works...
    During the day, my battery bank fully charges in about an hour so I wanted to use that extra energy for anything lol
    When the pump is running the panels are still producing a lot more power than the pump is eating.
    I tried running two pumps in parallel, that did not work well.. Even tried in series but it seem when you do that, you do not gain enough lift to make much of a difference.
    It seems That lift is the problem....
    Thanks
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 12 volt deep well pump question suggestions

    Not that this will help you, but for anyone else who might be interested ...

    Running two pumps in parallel will not increase the lift, only the flow rate.
    Running two pumps in series can increase the lift, but only if the two pumps are in the right places; merely placing one after the other won't do anything. Guess where the first pump needs to be? Yes; below it's maximum lift point. And the second one the same distance from the first. Murder on the pumps, btw; so easy to have one trying to suck through the other which is not good for either.

    At 40 feet, that Shurflo must be working hard.
  • joe cannonjoe cannon Registered Users Posts: 6
    Re: 12 volt deep well pump question suggestions

    Funny thing is ..the prostar says its only pulling 3.5 amps...I will use a different meter tomorrow to see if it is lying...also the voltage to the pump is between 13.4 volts and 14.4 volts depending on what state the controller is at the time...

    So ..no other ideas?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 12 volt deep well pump question suggestions
    joe cannon wrote: »
    Funny thing is ..the prostar says its only pulling 3.5 amps...I will use a different meter tomorrow to see if it is lying...also the voltage to the pump is between 13.4 volts and 14.4 volts depending on what state the controller is at the time...

    So ..no other ideas?

    It's probably not lying: these are pressure pumps; they don't draw significant power until they encounter resistance on the output side. Their lift ability is limited by the chamber capacity and the speed at which the diaphragm operates. The 8000 model is listed as being "self priming" to 8 feet, but obviously it can draw more than that. The actual depth to the water level and atmospheric pressure, blah blah blah ... gives one a headache real fast. :p Be glad it works at all!

    Other than changing the pump entirely there's not much you can do to get more flow. And if you were to pressurize the output you'll find the lift capacity goes down. That's about it for pumps: their design allows for a certain range of lift, flow, and pressure and you can gain on one without losing something from the other two. Darn physics!
  • joe cannonjoe cannon Registered Users Posts: 6
    Re: 12 volt deep well pump question suggestions
    It's probably not lying: these are pressure pumps; they don't draw significant power until they encounter resistance on the output side. Their lift ability is limited by the chamber capacity and the speed at which the diaphragm operates. The 8000 model is listed as being "self priming" to 8 feet, but obviously it can draw more than that. The actual depth to the water level and atmospheric pressure, blah blah blah ... gives one a headache real fast. :p Be glad it works at all!

    Other than changing the pump entirely there's not much you can do to get more flow. And if you were to pressurize the output you'll find the lift capacity goes down. That's about it for pumps: their design allows for a certain range of lift, flow, and pressure and you can gain on one without losing something from the other two. Darn physics!

    I dont have a problem with changing the pump or cost within reason...just need some inventive ideas...even possibly building a pump...
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 12 volt deep well pump question suggestions
    joe cannon wrote: »
    I dont have a problem with changing the pump or cost within reason...just need some inventive ideas...even possibly building a pump...

    Well one man's reason is another insanity. :p

    The Shurflo 2088 http://www.solar-electric.com/2088-443-144.html has about double the flow of the 8000 and is rated as being self-priming to 12 feet so it should handle the depth better.

    Otherwise you are into pumps like SunPower, Dankoff, or Grundfos which will cost at least 5 times as much and might require significant changes to the power supply. NAWS' pump page: http://www.solar-electric.com/sodcwapu.html
  • mike95490mike95490 Solar Expert Posts: 8,967 ✭✭✭✭✭
    Re: 12 volt deep well pump question suggestions

    There is no place on earth, where you can have a surface pump, suck from 40' down. I think 25' is the limit. Otherwise, the suction causes the pump to cavitate.

    So, your water table must be higher the 25', even though the well pipe is longer, which is a common setup.

    Adding another pump, will increase the flow, and further reduce the water level in the well, and it may suck it dry, and you have wasted effort. It may be worth a volume test, to see what the well can produce, before you buy more pump.
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  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 12 volt deep well pump question suggestions

    To clarify what Mike is saying:

    40 feet of well depth is not the same as 40 feet from the surface to the water. The lift only has to be from the water level up. Even if the pick-up is at 35 feet, the lift is still from the top of the water in the well.

    I too am amazed that this works at all, and wouldn't figure the water lift depth to be more than possibly 20 feet.

    But you can left water with a surface pump from up to 80 feet, with the trickery of a convertible jet pump (there will be two lines descending into the well). Usually 50 feet is considered time to seriously think about a submerged pump. And while we're at it, higher elevations adversely affect a pump's lift capacity. Bernoulli, pressure differentiation, blah blah blah ... my head hurts again. :p
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