Off grid well pump

System · August 2008

Hello all,

We are in the process of re-opening an old homestead, last used 5 or 6 years ago.

The well is drilled, has a 6 1/8" ID casing, the water surface (unused) is about 12 feet below grade. Currently there is a 230 VAC submersible 1/3hp pump at 122 ' (110' below water surface).

We may be hooking into the grid sometime, but currently are not. We are using propane and have a 800 watt (950 peak) gas generator.

The line from the well runs through the air to the peak of the house across 104' 5", that is about a 25' lift, from the well, it drops down (inside the house) about 8' to a 500 gallon storage tank.

I'm in northern ontario canada, and it gets quite chilly here in the winter, so without the line being buried (which I can't do this year) it would freeze it it stayed in the line. So it's set up to run to fill the storage tank, drain back to the well, leaving the line empty til next filling (couple of days to a week).

The problem is that the generator I have is only 110vac, so I am trying to find a solution that isn't going to cost hundreds of dollars that I can't get set up right away to tide us until we have full power.

Tom

halfcrazy · August 2008

Re: Off grid well pump

the cheapest solution is going to be a inexpensive generator. anything you try to do in the well is going to get expensive and if you ever get utility power or a offgrid solar system the pump you have is fine. so i would say look at the discount area at home depot they have refurbished generators pretty reasonable. i saw a 5500 watt Coleman at my local hd yesterday for 300 and change

System2 · September 2008

Re: Off grid well pump

See what a 110 V. 1/2 HP submersible costs. Changing the pumps out will be a chore as deep as it is but a new pump shouldn't cost more than $289.oo. You should be able to re-use everything else except the well wire shrink tube kit and some pipe dope or teflon tape.
You might also see what an auto-transformer would cost. If you plan to go solar later you would have a use for an X-240 autotransformer from Outback, see www.outbackpower.com. If you go with a series stack 240V system later that is. Transformers do consume energy though.
Nothing wrong with getting a 240V generator either. just some ideas to compare. Also nothing wrong with 1/3 HP pumps. Just not always in stock and I heard from a well driller the manufacturers just stick a different name plate on the same pump as a 1/2 and sell it as a 1/3 HP which outperforms its rating. Not 100% sure its true mind you. The guy did seem to know his well pumps. sorry I don't know how to make that www. thing into a link for you.

icarus · September 2008

Re: Off grid well pump

In the short term, I agree with Halfcrazy, get a cheap 240vac genny,,, or get a good 240 genny now and use it for other things later.

In the longer term you might consider some other options. Consider how much water you will need on a daily basis. We live quite comfortably with a small shurflo submersible, pumping into a 50 psi tank. I have built an automatic drainback system. If in your case you can bury the water line your way better off than I was. We pump out of the lake, and are on bare rock, so freezing is a real issue. (-40 is common!)

In any event, look through this site and you will find a whole thread on freeze protecting a water system. (http://forum.solar-electric.com/showthread.php?t=1831&highlight=shurflo+submersible

Good luck,
Tony

PS Where in Northern Ontario are you?

wild01 · March 2009

Re: Off grid well pump

If I were you I would replace the well pump w/ a grundfos sq 1/3hp.

(not an sq flex or sqe these are much more expensive and offer very little benefit-good pumps but if cost is an issue totally unneccesary)

you shouldn't need to pay more than 600-650 for this pump, if you get a quote for the pump higher then that keep shopping

this pump will be at the outside of what you generator will handle, but it is a very reliable pump and it soft starts with zero surge (most pumps require 3-5x as much amperage to start as they do to run) also if you ever plan to install solar these pumps run very well on inverter power, and are even labled for use with msw inverters. I replaced my myers rustler 1/2 hp pump with one of these last year and have been very happy. i toasted 3 gennys with the rustler, and my 2500w psw inverter wouldnt even try to run it. my current genny doesn't even bog down when I plug in the well, and the inverter shows 800w draw when I use it.

One side note if you get a grundfos, don't let the delivery driver leave it outside for pickup during winter, the pump motor is liquid filled and it is not freeze protected.

mikeo · March 2009

Re: Off grid well pump

With that much lift I think you may need close to a 1/2 horse motor to deliver much water volume. I power my 1/2 horse 240 volt Franklin submersible (similar to the Myers Rustler, same motor) with my SW4024 inverter and have no problems. The max run current is nearly 6 amps and the Starting Factor is 1.6 . I wired it through a 5KVA 120/240 Volt transformer I picked up on EBAY for about $30.00 + $60.00 shipping. Using an autotransformer as sold by OB or Xantrex is more efficient in this particular application should on come available used cheap enough. Fortunately in my system the pump motor only runs about 45 seconds to pressure the system and then shuts off, so the duty cycle is pretty low. To run this on a generator, you would need a 3000 watt generator. If I am cyphering correctly, 6 amps * 1.6 SF = 9.6 amps * 240 volts = 2300 watts starting power.

Lefty Wright · March 2009

Re: Off grid well pump

What generator do you have?

Some gen sets with only 110V outlets do have 240V available. If you have a 110V duplex outlet measure from one hot slot to the other. If you see 240V you will just have to make an adapter with 2 cord caps and cords and a steel 4x4 box.

But if you are off grid another generator can't hurt!

Off grid well pump

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