Solar water pumping/pulling hair out... is it ever ok to....

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Rustyknife
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My RE system: 1,800 watts of poly panels. 110 v dc, flexmax 80 charge controller, 4 six volt t105s wired in series for 24 v dc and 225 amp hours. vfx3524 inverter. Flexnet dc meter. No generator at this time.

Solar water pumping/pulling hair out... is it ever ok to....

Post by Rustyknife » Sat Jun 04, 2016 7:13 pm

Im going to just come out there and say it....is it ever ok to pull voltage from the solar panels before the charge controller to run a well pump?

Here's the situation. Currently running 1380 watts worth of panels. Three 230 watt 24 volt panels are wired in series and then paralleled with another set of three. Typical voltage to the charge controller is 100-102 v DC. Entire system is outback with a vfx3524 inverter. 24 volt battery bank.

My well is 465 feet deep and recovers at a rate of 30 gpm. Originally the static water level was measured at 95 feet. At this current point in time the static water level is at 170 feet.

For solar water pumping up to this point, I have been using a simple pump hand pump with the 24v solar pump motor option. It was "claimed" to pump to a depth of 230 feet head however this is not the case. I pump from the well into an open storage tank of 500 gallons and from there to a 24 volt booster pump and to a pressure tank and then basically running water at that point. The simple pump worked fine in the rainy season and the 1 gallon a minute output was fine because I could store the water at the surface in the 500 gallon tank. Now that it has been dry and the static water level in the well has dropped significantly, its too much for the simple pump. The 24v motor rated at 8.7 amps, will blow a 20 amp fuse. I assure it is not the wiring pump motor etc I've exhausted my diagnostics. Its simply that the simple pump is not as robust as described and simply cannot be relied upon for water, period.

At this point I wish I hadn't drilled a well and relied on rain water to satisfy my water needs, but currently I have an 8300 dollar hole that I cant get water from, so I am pretty committed.

Basically I need to replace my current well pump with a deep submersible that will be a reliable and robust system. Cost is always a factor. I have several options, but I'm basically pinpointing on grundfos pumps

Since I only have one inverter and I don't want to purchase another 2000 dollar inverter to run a 220V pump I would like to commit to a 110v pump or an sqflex

The 110v pumps, specifically the 5s05-13 in my case from studying the pump curves and pump efficiency, will fit the bill, but will take a whopping 55 amp start up and 12 amp running, or around 1200 watts, to pump about 5 gallon a minute. Im sure the outback inverter could start it, but i'm not sure if I'm running my whole house on the inverter what will happen, and I hate the idea that if my inverter quits I cannot pump water, however I'm sure I could buy a cheap inverter in an emergency. This is my cheapest option at 800 dollars for the pump, 300 dollars for the drop pipe and 250 ish dollars for the wires.

The sqflex pump is very expensive at 2000 dollars, and 500 dollars for the control boxes, plus pipe, plus wires, however, with a 6sqf-2 pump I could pump 5 gpm off of 400 watts, but the kicker is I really need over 100 v to run it. Either a/c or d/c. I thought if I could utilize the power from the panels before the charge controller I could run the pump off of dc with no extra strain on my inverter......Im pulling my hair out

I dont want to make the wrong pump choice again, as I have already invested 4000 in the simple pump and it did not work.......Please help with any input you may have

bezalel
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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by bezalel » Sat Jun 04, 2016 7:41 pm

You must have a heavy water well.

Have used SQFlex, simple, and conventional submersible pumps in installations. It takes about the same amount of power to lift the water no matter what type you use. The difference is the start-up power surge. The Grundfos SQFlex has the advantage of a slow start-up power pull using the helical rotor pump vs. the speed-controlled synchronous motor of a conventional submersible. The SQFlex also can be run by an AC generator in an emergency. Have dedicated multiple PV panels to run an SQFlex on DC during the day for refilling storage tanks using the float switch option. Go for the highest voltage string combination you can. If you get an SQFlex, be sure to get the 5-year warranty extension.

Cost-wise, you may consider using an X-240 transformer to jump the voltage up to 220/240 and using the smallest HP conventional 220VAC submersible that the pump curves let you get away with. That is cheaper than a second inverter or an SQFlex. Mixing in a variable speed AC drive may be another method of 'soft-starting' the power surge. Haven't worked out the amp/watt details to find the limits. Too late at night.

Spend any money you saved in more PV panels. Can't have enough.

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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by sodamo » Sat Jun 04, 2016 10:42 pm

Have you considered DC pumps that run directly from the panels or batteries?

Google Lorenz
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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by larrywa » Sun Jun 05, 2016 6:31 am

I did my well about 8 years ago using the biggest 120 vac grundfos sqflex pump I could get= 1/2 hp. I only have 150 feet of depth and I can barely get 60 PSI with that depth and 100 feet of water head over top of the pump.

I doubt you will get enough lift from one of these with your well depth. You will need to go 240vac to get at least 3/4 hp. Then you will need a second stage to get any head pressure in your house, from the holding tank. Need to study the grundfos lift vs. pressure charts. Head is good :)

I would invest in a second inverter to get your 240vac. This sound like you could use the reserve capacity for your house anyway.

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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by JRHill » Sun Jun 05, 2016 6:37 am

Our well is solar powered and it went in before the separate, OutBack system system was configured. In hindsight, we could've used the same panels and batteries as the house but just connected the inexpensive Morningstar controllers to the bank and connect the load to the well to that. Check out the components used to the right.

Oh, yeah, our well isn't as deep as yours but it recharges less in the summer and even slower yet during this drought. We just have to use care in usage so as to not suck air.

Best,
Jim

Rustyknife
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My RE system: 1,800 watts of poly panels. 110 v dc, flexmax 80 charge controller, 4 six volt t105s wired in series for 24 v dc and 225 amp hours. vfx3524 inverter. Flexnet dc meter. No generator at this time.

Re: Solar water pumping/pulling hair out... is it ever ok to

Post by Rustyknife » Sun Jun 05, 2016 7:19 am

sodamo- the lorentz pumps look very similar to the sqflex. Either way I will need a high voltage d/c source 100 volts plus. And the higher the better so my voltage drop through a 250-300 foot wire isn't astronomical. There again. It seems not cost effective if I have ANOTHER set of pv panels that are dedicated to just running the water pump. It would be far cost effective to utilize the same panels I have now, but just pull the high voltage off before it reaches the charge controller and steps it down to 24v dc for the battery. The more I think about this the more I think it could work possibly? Is that a big big no no?

Larrywa- Looking at the pump curves I really should be able to run a 1/2 hp easily from my head depth. If I understand correctly your pumping directly into a pressure tank at 60 psi, that is a significant load on a pump. I however am pumping with no restrictions into an open storage tank, which greatly increases my pumping depth ability.

I just hate the idea of stepping up for another inverter as there are not many applications I need 220 v for.

I will look into the transformer setup and see if its feasible.

I just wish I would have studied rain water catchment more before I drilled a well. I just had a pond dug off the corner of my shop/house that will hold approx 200000 gallons and cost just 2000 dollars. I can catch 5000 gallons of water off my roof in 1 inch of rain and it rains 44 inches a year here. All my water supply needs can easily be met with rain water catchment tanks and filters....oh well, live and learn.

Image

larrywa
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My RE system: FlexPower Two
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Mate3 v3.015.005 (works excellent!)
Hub 10.3,
PV:1000W east@45, 600W west@45, 2400W south@19 deg.
Battery:48v @ 130Ahr Crown batteries, deep cycle <$380 for 6.25kWh

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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by larrywa » Sun Jun 05, 2016 7:36 am

Rustyknife wrote:sodamo- the lorentz pumps look very similar to the sqflex. Either way I will need a high voltage d/c source 100 volts plus. And the higher the better so my voltage drop through a 250-300 foot wire isn't astronomical. There again. It seems not cost effective if I have ANOTHER set of pv panels that are dedicated to just running the water pump. It would be far cost effective to utilize the same panels I have now, but just pull the high voltage off before it reaches the charge controller and steps it down to 24v dc for the battery. The more I think about this the more I think it could work possibly? Is that a big big no no?

Larrywa- Looking at the pump curves I really should be able to run a 1/2 hp easily from my head depth. If I understand correctly your pumping directly into a pressure tank at 60 psi, that is a significant load on a pump. I however am pumping with no restrictions into an open storage tank, which greatly increases my pumping depth ability.

I just hate the idea of stepping up for another inverter as there are not many applications I need 220 v for.

I will look into the transformer setup and see if its feasible.

I just wish I would have studied rain water catchment more before I drilled a well. I just had a pond dug off the corner of my shop/house that will hold approx 200000 gallons and cost just 2000 dollars. I can catch 5000 gallons of water off my roof in 1 inch of rain and it rains 44 inches a year here. All my water supply needs can easily be met with rain water catchment tanks and filters....oh well, live and learn.

<image snipped>
If the DC can work, get a few more panels and tack them into your existing system. Make sure your ground fault detection is working on your PV system and fuse appropriately.

I would be interested to see what your price comes in at for the transformer capable of running the 240vac pump, especially if it doesn't have soft starting. You may be into the second inverter price range.

All the best.
Last edited by larrywa on Sun Jun 05, 2016 1:15 pm, edited 1 time in total.

Ralphg
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My RE system: 2 GVFX3648, 2 FM-80, MATE3, 4000 W of various panels on 2 trackers, 33HP Kubota 12KW primary source diesel genset. 8 Surrette 6CS17P (6V 546AH ea) Grundfos 6SQF2 water pump (solar). Homebrew power monitor and controls, off grid 20 years.
Location: Southern OR

Re: Solar water pumping/pulling hair out... is it ever ok to

Post by Ralphg » Sun Jun 05, 2016 10:41 am

I currently use a Grundfos 6SQF-2. It is powered by one 230W and one 130W solar panel connected in series directly to the pump. These panels are dedicated for only the well pump. Each panel outputs about 7 amps. The combined voltage is about 48. Normal operating voltage is about 42. Total head to the holding tank is 230 ft. The pump produces about 2.3 gallons per minute into a 2500 gallon holding tank that is 1100 feet away. A 3/4 HP 120 volt Myers boost pump raises the pressure from the holding tank to 50psi for household usage.

My Grundfos pump is externally controlled only by a solid state relay that simply disconnects the power from the solar panels. Relay control input is from a 5VDC float in the holding tank. There is no other pump controller or hardware needed.

I too spent a great deal of time and effort researching and designing this system. Yah, the SQF is expensive, but you get what you pay for. The pump system has worked flawlessly since summer of 2012.

Hope this helps.

Rustyknife
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My RE system: 1,800 watts of poly panels. 110 v dc, flexmax 80 charge controller, 4 six volt t105s wired in series for 24 v dc and 225 amp hours. vfx3524 inverter. Flexnet dc meter. No generator at this time.

Re: Solar water pumping/pulling hair out... is it ever ok to

Post by Rustyknife » Sun Jun 05, 2016 5:44 pm

Ralphg wrote:I currently use a Grundfos 6SQF-2. It is powered by one 230W and one 130W solar panel connected in series directly to the pump. These panels are dedicated for only the well pump. Each panel outputs about 7 amps. The combined voltage is about 48. Normal operating voltage is about 42. Total head to the holding tank is 230 ft. The pump produces about 2.3 gallons per minute into a 2500 gallon holding tank that is 1100 feet away. A 3/4 HP 120 volt Myers boost pump raises the pressure from the holding tank to 50psi for household usage.

My Grundfos pump is externally controlled only by a solid state relay that simply disconnects the power from the solar panels. Relay control input is from a 5VDC float in the holding tank. There is no other pump controller or hardware needed.

I too spent a great deal of time and effort researching and designing this system. Yah, the SQF is expensive, but you get what you pay for. The pump system has worked flawlessly since summer of 2012.

Hope this helps.
That's really good information to know! When I was looking at the sqflex pumps, I was under the impression that you needed to purchase the 500 dollar control box for it to function and another 500 dollar control box if you wanted the option to use a generator, or in my case, 110vAC backup from my inverter.

May I ask what the length of wire you have from panels to your pump is and what gauge you're using?

With my current water level dropping almost 80 feet to its current level at 160 feet and its really only the first part of a drought, I've considered dropping the pump in at around 300 feet, and I could use probably another 50 foot of wire easy to get up to the roof for panels.

If I attempted a 48 vDC system at 7 amps for 350 feet of wire at a 3% voltage drop I would need awg-4 !

I actually currently have 5 extra panels that I COULD dedicate to this project. They are each 100 watt 12 volt panels. Wired in series I could possibly attain 102 ish volts at 7 amps. At the same distance I could get by with an 8 gauge wire at a 3% voltage drop.

The 6sqf-2 according to the pump curves looks ideal for my well and just assuming a drop down water level to 200 feet of head(planning for worst case) I should still be able to yield 5.6 gallons at 400 watts.

I have a relay already for my float switch that would be ideal for this.

So do you think my best bet is to buck up and purchase the 6sqf-2? I REALLY like the idea of being able to pump water even if your inverter ceases function, so that seems attractive to me.

My brain actually hurts from thinking so much about this, lol

Here's my current setup. The well is inside the shop that was previously posted.

Image

I don't want to be just another prepper worried about doom and gloom, but I really want a RELIABLE source of water. There's something satisfying about knowing if the world went to heck in a handbasket, I can go in my shop, shut the door and at least have good clean water until life simmers down....

If at all possible I would like to be able to pump water all day every day as long as the sun was shining. I intend to put three fish tanks on the outlet side of my water storage tank to brood tilapia, and then raise them in the pond outside....but that's another project that's years from completion.

It did rain once at 3.3 inches and I feel like I caught 20,000 gallons or more, but its slowly evaporating away. The SE corner of the building where the pond is, has significant solar exposure.

Image

larrywa
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Hub 10.3,
PV:1000W east@45, 600W west@45, 2400W south@19 deg.
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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by larrywa » Sun Jun 05, 2016 6:29 pm

You still need the CU 200 control box but I believe it is included for the $2100 US price.

http://www.solar-electric.com/lib/wind- ... _Guide.pdf.

This would be more dependable fed off your 120vac inverter and spend the other $1300 on more PV panels. You could have water when the sun doesn't shine, rather than depending on climate where you are. We wouldn't have any water for most of December into March, where we are. :grin: The higher voltage would allow smaller wire size and be compatible with standard supplies , down the road, or should it be repurposed. Another savings. Later if you add another inverter for 240 vac most of these pumps are dual voltage convertible.

IIRC mine cost me about $800 US (2007-8) for the variable speed, continuous pressure model with the CU 301 controller to send the speed signals. It also came with a pressure tank and pressure sensor. You may not need those parts but that may make it cheaper.

Then you have DC breakers and panel to purchase, maybe, let alone a DC GI system if you don't feed it through your OB GFI detection system. AC breakers are cheap and common. DC breakers are special devices needing arc snuffers to break continuous current.

Ralphg
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My RE system: 2 GVFX3648, 2 FM-80, MATE3, 4000 W of various panels on 2 trackers, 33HP Kubota 12KW primary source diesel genset. 8 Surrette 6CS17P (6V 546AH ea) Grundfos 6SQF2 water pump (solar). Homebrew power monitor and controls, off grid 20 years.
Location: Southern OR

Re: Solar water pumping/pulling hair out... is it ever ok to

Post by Ralphg » Sun Jun 05, 2016 9:30 pm

My pump is 170 feet deep using 10G wire, connected to the panels through a 100V 10A fuse and the solid state relay. Panels are at the well shed.

Using a well pump with an AC motor for off grid use is not very efficient. The Grundfos 5SQE05-180 which has an AC motor takes 1090 watts to pump 3.3 GMP at 230 feet head. The Grundfos 6SQF-2 which has a DC motor does the same work with 330 watts of power. Less than one third the power of an AC motor.

I totally agree with the previous comment that backup power using 120VAC is desirable and may be required. With the Grundfos SQF pumps you could switch in a 90-230 VAC source to the pump. My concern with a direct AC backup supply is that the pump would operate at 100% load/speed at all times using an AC source. There would be no way to control the pump speed. An alternative, (which I use) is a 48 VDC switching power supply like this one.

http://www.mpja.com/48-Volt-Power-Suppl ... /18437+PS/

This inexpensive power supply maxes out at 240 watts and gives me water in the winter when required.

My water pumping system was designed for reliability/simplicity, efficiency, and cost, in that order.

What I would really like is a deep well pump, the quality of the Grundfos, only with a basic brushless DC motor without any electronics. Anyone aware of such a pump out there?

Cheers

blackswan555
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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by blackswan555 » Mon Jun 06, 2016 5:36 am

I would take another look at what you have first & a chat to their tech help , From a quick google they do seem to do what they say on the box ?

Then another option is a "normal" deep pump, 3ph will give you better efficiency, Run off your 120v controlled with a Variable frequency drive, A lot simpler than it sounds, 120v 2 wires in, 3ph 3 wire out (+ earths of course) that will give you soft start, virtual full torque all across its rev range & you can overdrive by 10%, Will run off your inverter or generator (you can regulate max it will draw) UK Company I use but you can get them in most voltage ranges, http://www.drivesdirect.co.uk/index.html Bottom of page, I have a friend who runs one on a 2kw 3ph pool pump, 1 vfx 3024E & 15kva gen, Has a Party and normal position switch, Normal is no infinity effect, Run at 40%, massive fuel & water savings, Flick it to party, pump runs 110% & gen kicks in,

Tim
My comments are based on my experience and research, They are not endorsed or checked by Outback.I am an independent British electrician living in Spain, So please take this into account when reading /acting on my post`s.

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Re: Solar water pumping/pulling hair out... is it ever ok to

Post by bezalel » Mon Jun 06, 2016 5:51 am

Another thought....
Your pictures show the well, etc... in a building with a pretty high ceiling. It looks like you can elevate the tank about 10-15 feet on a tower. With large diameter distribution piping this will give you enough head to operate toilets and most other applications without the secondary pressurization pump. The difference to the well pump will be negligible and you have a water supply even if all electricity is off. A support structure of 6x6 posts with cross-bracing should be adequate.

Rustyknife
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Joined: Mon Jan 25, 2016 6:17 pm
My RE system: 1,800 watts of poly panels. 110 v dc, flexmax 80 charge controller, 4 six volt t105s wired in series for 24 v dc and 225 amp hours. vfx3524 inverter. Flexnet dc meter. No generator at this time.

Re: Solar water pumping/pulling hair out... is it ever ok to

Post by Rustyknife » Mon Jul 18, 2016 5:39 pm

As an update, with the help of 5 people today we installed a grundfos sqflex! Model 6sqf-2! I set the pump at 300 feet, static water level at 170. I havent purchased my panels yet but have sourced some 60v dc panels that are 240 watt monos brand new, four for 804 dollars including tax. Im going to wire them all in series and send it straight to the pump and pump water all day long.

In case of cloudly inclement weather I wanted to be able to pump water, so based on the amperage draw of 8.5 listed in the owners manual I calculated a 3% voltage drop as needing 8 awg wire at 300 feet, so thats what I installed.

I plugged it into 110 to test it. Turns out the pump draws 460 watts lol......thats 4.5 amps at 110v.....I could have used a 10 awg. Live and learn. Life is good. Im hoping with the 960 watts worth of mono panels at 200+ vDC and an 8 awg wire, seeing as the pump can pump 30-300 volts I will be able to pump even in low light conditions. I need to disinfect the well and purchase and install my panels and start filling my pond. Thanks for the help guys!

Ralphg
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Joined: Fri Nov 07, 2014 1:03 pm
My RE system: 2 GVFX3648, 2 FM-80, MATE3, 4000 W of various panels on 2 trackers, 33HP Kubota 12KW primary source diesel genset. 8 Surrette 6CS17P (6V 546AH ea) Grundfos 6SQF2 water pump (solar). Homebrew power monitor and controls, off grid 20 years.
Location: Southern OR

Re: Solar water pumping/pulling hair out... is it ever ok to

Post by Ralphg » Tue Jul 19, 2016 8:55 am

Glad the system is working. Thanks for and please keep us updated on the system performance.

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