Goat farmer needs water!

troybrownrigg
troybrownrigg Registered Users Posts: 18 ✭
in Off Grid Solar & Battery Systems #1
First off I'm trying to run a franklin submsible pump 115 vac 12 amp. What size pure sine wave inerter do I need? (type / size) A zantrex 2000 unit won't run it why? Second I would like to pump large volumes of water from two 16" irigation wells water table @ 25' well depth 75' total: lets say 60- 200 gpm A design idea for a complete system.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #2
    Re: Goat farmer needs water!

    Are you looking to solar to save money or because there is no grid power available in the area (at a reasonable price)?

    Next, do you need to only pump water when the sun is up (around 10am to 3pm) to above ground storage (pond, cistern, flooded fields)--I.e., no batteries. Or do you need to pump on demand 24x7, 4 seasons a year? What is the output pressure (open to pond or 40+ psi for sprinklers, etc.).

    Very roughly, if you can setup to only pump when the sun is shining (solar panels + solar compatible pumps) is much less expensive--probably over the long term, 1/4 the cost (or less) per kWH hour.

    If you have a pump + inverter/battery setup you want to try and make work... You might look around for a VFD (Variable frequency drive). If the pump was 3 phase (guess not this one) or is 3 wire (starting capacitor is run up to the well head), then a VFD can "soft start" the pump and also limit maximum power by varying the frequency to the pump motor.

    2kW to run a 115 VAC / 12 amp pump is probably going to take a much larger inverter to run a "raw" induction motor (they can have 5x running current for starting).

    Any way, knowing more about your power/pumping requirements can help us recommend some cost effective options for you to look at.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #3
    Re: Goat farmer needs water!

    as to the inverter not running it there are 2 things that can influence that with the first being a very high start surge. i'm not familiar with either the pump or the inverter to know what they need or can do, but i'm sure that can be looked up by you.

    the 2nd thing is low battery voltage if the battery capacity running the inverter is too low. if you don't have a fair amount of capacity the high draw of current will pull the voltage down too low and kick out the inverter from operating. this can be the case when one has enough capacity too if the wiring is too small or the connections are poor as these conditions will present a voltage drop and still cause the inverter to shut down.
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  • troybrownrigg
    troybrownrigg Registered Users Posts: 18 ✭
    #4
    Re: Goat farmer needs water!

    I'm sitting on Arizona's largest water table 25' below this ranch. Three wells 16" dia. with a capability of 240 gpm. Basically I need to pump water in volume over fields of bermuda grass the most efficnet way possble. Day time only, is ok. The electric bill would wipe out all the profits if I used it! I figured using the 460vac pump 24/7 would be well over $1,000 a month per well. If I could come up with a system at over 60 gpm I could make several of them to get to 400gpm.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
    Re: Goat farmer needs water!
    troybrownrigg wrote: »
    First off I'm trying to run a franklin submsible pump 115 vac 12 amp. What size pure sine wave inerter do I need? (type / size) A zantrex 2000 unit won't run it why? Second I would like to pump large volumes of water from two 16" irigation wells water table @ 25' well depth 75' total: lets say 60- 200 gpm A design idea for a complete system.

    I am not surprised that a 2 kW inverter won't start that pump. The pump is problem #1. There's no doubt its start-up surge exceeds the inverter's capacity. Add in to that there is probably significant Voltage drop in the wires and you have a situation that won't work.

    Follow Bill's advice and get a handle on exactly what will do for our pumping needs. If you can store in an above ground tank then you can pump slowly over time and let the tank make up the flow difference.
    200 gallons per minute is a lot of water, but regrettably not uncommon for livestock or irrigation.

    I'll tell you advance the solution isn't going to be cheap. Moving 8 tons of water in a minute takes massive amounts of power, no matter how you do it. Do you have a number for total gallons in a day? It can be much more economical to move it slowly over longer time, if possible.
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  • troybrownrigg
    troybrownrigg Registered Users Posts: 18 ✭
    #6
    Re: Goat farmer needs water!

    I thought the zantrez 2000 is too small to run the franklin 115 vac 10 gpm submersible. I've got 640 watts of solar panels and a 750 watt windmill to a battery bank 12vdc. I'm also considering a dc submersible pump motor 30 gpm would be a start for the domestic house water needs. I plan on either a d/c pump or larger inverter, and increasing the the number of solar panel and size of battery bank. As soon as I can figure out how to get a submersible pump to run off a system!
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  • troybrownrigg
    troybrownrigg Registered Users Posts: 18 ✭
    #7
    Re: Goat farmer needs water!

    Dr. Alfred Lanning: In Arizona currnetly there is a shortage of Afalfa It's shipped in from Utah. Most farmers have given up on Alfalfa because it cost to much to pump water using the power grid. Currnetly the price may exceed $20.00 per 80lbs bale. This will wipe out alot of ranchers soon! If a sytem can be build for solar pumping it could save this farm! For the Question Can these d/c pumps pump 80 gpm each and what is the amount of solar panel wattage to power them? Does it require a battery bank?
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  • solarix
    solarix Solar Expert Posts: 713 ✭✭
    #8
    Re: Goat farmer needs water!

    In general, if pumping water with Grid AC is too expensive for you, then you really won't like the cost of the equivalent solar system. However, if you can make use of solar incentives or do something innovative - there may be hope for you. You should qualify for a REAP grant from the Dept of Ag. That will pay 25%, but the yearly deadline of June 15 just went by. Utility rebate of up to 50% is probably available to you even if you are off-grid. Of course the FED tax credit is 30% and double declining depreciation is huge on businesses that have the tax liability to use it.
    Now, the slower you pump the water, the cheaper the solar equipment. Think about just pumping directly off the solar panels when they are working (so no batteries or inverter is needed), Still, I'm not aware of any large scale (>20gpm) DC solar pumps. Could always convert a direct-drive centrifical irrigation pump to a large ($$$) DC motor I suppose. With your shallow water, check out something called a rope pump that is used all over South America. Would have to scale up the idea and motorize it, but would be simple, cheap and efficient.
    The era of cheap energy is coming to an end and will change the nature of what we do and how we do it.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #9
    Re: Goat farmer needs water!

    Pumps: there's a lot of them

    Take a look at the SunPumps here: http://www.solar-electric.com/suscsbrdcsus.html
    These can run off quite a wide variety of DC power sources. By going directly to DC you eliminate the losses inherent in converting to AC before powering the pump. They are not designed to pump high volumes, however.

    Another choice is the Grundfos line: http://www.solar-electric.com/grsqpu.html
    The largest of these is capable of 85 gpm from 45 feet. From the chart we see that it would need 1400 Watts of panel. The pump alone is $2,000, not including wiring, fittings, and control unit.

    On the other hand the "AC choice" would begin by replacing your 115 Volt submersible with a 240 VAC unit (greater efficiency). You need $3000 worth of inverter to run it, plus batteries, plus panels and charge controller. My guess is changing the pump out for the biggest Grundfos and its related equipment would end up being cheaper.

    BTW, I'm not Dr. Lanning; I just like to quote him. :p
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  • troybrownrigg
    troybrownrigg Registered Users Posts: 18 ✭
    #10
    Re: Goat farmer needs water!

    How does one power a 240vac pump with these inverters which put out 240vac from one leg? The current 240 vac pump has two legs of power at 120 vac each. I would be afraid that the 240 from these inverters would fry my pump that's why I'm going to a 120 vac pump!
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  • troybrownrigg
    troybrownrigg Registered Users Posts: 18 ✭
    #11
    Re: Goat farmer needs water!

    I've been using the grid to operate a 10 hp 460vac 7500 watt pump for 8 years. The biggest cost on this ranch is the electric bill. I dump about $1500.00 amonth into upgrading systems each month. My average electric bill is $500.00. Any means to pump water cheaper is a very big issue. Going solar sounds cheaper in the long run, and may be the only way to continue to operate!
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #12
    Re: Goat farmer needs water!
    troybrownrigg wrote: »
    How does one power a 240vac pump with these inverters which put out 240vac from one leg? The current 240 vac pump has two legs of power at 120 vac each. I would be afraid that the 240 from these inverters would fry my pump that's why I'm going to a 120 vac pump!

    No worries.
    The 240 VAC in your home service is on two legs with a center neutral. 240 Volt equipment doesn't use the neutral, although often it is included in wiring of some things so that 120 Volts will also be available. Electric stoves, for instance, have 120 V for oven light, panel light, controls on the modern ones, outlets sometimes.
    If you look at the wiring of a 240 V electric heater or hot water tank it's two wires and a ground. Some pumps are a bit more sophisticated, with remote "soft start" equipment for instance.
    An inverter such as the Xantrex XW line has 240 Volt "split" output complete with neutral.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #13
    Re: Goat farmer needs water!
    troybrownrigg wrote: »
    I've been using the grid to operate a 10 hp 460vac 7500 watt pump for 8 years. The biggest cost on this ranch is the electric bill. I dump about $1500.00 amonth into upgrading systems each month. My average electric bill is $500.00. Any means to pump water cheaper is a very big issue. Going solar sounds cheaper in the long run, and may be the only way to continue to operate!

    The capital investment would be murder to do it all at once. You might start out with one pump first and see how that performs. I know what you mean about power 10 HP pumps. The only thing you have going for you is no need for a lot of lift. The distance it needs to travel afterward, however, can be daunting.

    Don't know what your land is like, but you should take a real good look at it with an eye towards locating a huge central tank if at all possible. Water is heavy an requires a lot of power to move it about. That power doesn't come cheaply, no matter what the source. I think you know that already. ;)
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  • troybrownrigg
    troybrownrigg Registered Users Posts: 18 ✭
    #14
    Re: Goat farmer needs water!

    I solved the first problem with the 115 volt pump, I'm usinging the Aims 8000/16000 power inverter. Seems to run it without any issues! I'll let my bank account recover for a bit before I tackle the larger volume pump issue.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #15
    Re: Goat farmer needs water!
    troybrownrigg wrote: »
    I solved the first problem with the 115 volt pump, I'm usinging the Aims 8000/16000 power inverter. Seems to run it without any issues! I'll let my bank account recover for a bit before I tackle the larger volume pump issue.

    Ah yes: AIMS inverter. 8 kW, 12 Volt? That's nearly 800 Amps DC, not including the surge rating. Four parallel input lines because it is not possible to handle that much current on any single piece of wire. Needs a separate fuse per line. This design is what is known as "bad practice" in electrical parlance. Or in layman's terms: potentially dangerous design that shouldn't be allowed. Keep in mind that a quality Xantrex 6kW inverter is 48 Volts: less than 150 Amps.

    You might want to upgrade your inverter to something a little bit better.
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