Inverters / controllers for well pump & lights

[Dlbecker]

We have 6 x 12v lithium batteries and 3 x 320w solar panels but we are stuck on what kind of inverter/controller to get that would run our 100ft deep 240v 3/4hp well pump & also use it for some 120v lights. We have a connection to our elec box to plug in a generator to run all of that but want to use solar since gas is so expensive now.

 

[MisterSandals]

3 x 320w solar panels

You need to provide the Voc of the panels to make sure potential SCCs can accept the voltage.

Is there an option for a 4th panel? That make a solution easier usually.

 

[MichaelK]

Here is a pump chart provided previously by another member, Mike95495. Scrolling through the data, it appears that your pump might consume 8.4amps while running, but 31.4amps right at startup. For my own pump, a 1hp Grunfos, I find I'm getting about 9.5A and 38A. So, I feel the chart is very accurate. So, you'll need an inverter that can continously supply at least 2016W, and surge to 7536W.

Right at the start, I'd say your solar input would be totally inadequate. Using the 2X rule, I'd suggest you have ~4000W of panels to run your pump, or roughly four times what you have now. My pump needed 2280W to run, so I installed 4500W of panels. It works. My panels however are on rotating mounts, so they can face East in the morning and West in the afternoon. With this arrangement, I can pump water from 8:00AM till 4:00PM continously, without battery depletion.

Well pumps have very high starting surges, 4X or so, and most demand that surge for about a second or two. Keep in mind that most budget-model AiO units have next to no starting surge, maybe 2X for only 16 milliseconds or so. You should shop for an inverter that has a minumum of a 5 second starting surge. I've got a Schneider XW+6848. The Outback Radian is another viable choice. Both put out split-phase 120/240VAC.

A well-pump is just about the biggest thing anyone attending this site is going to ever run. The good news though is that a system that can run your pump, can run just about anything else, including lights, TV, refrigerators, freezers, and power tools.

You MIGHT get a smaller inverter, like a Conext 4048 to work, but the specs are a bit iffy, and you are right at the high end boarderline. If it does prove to be inadequate though, the good news is that you can parallel a second one and sync them together to double output.

The batteries though are not the right number. You are very much in 48V territory, here, and you need four of them in series to make a 48V battery. Can those batteries be wired in series? If not, you have to get rid of them and start over. If they can, then you should get two more so you can make a 4S2P battery bank.

Don't buy anything else until you have a clear plan. You don't want to repeat things like buying the wrong batteries. What every off-gridder should have though is a good clamp meter that can read "inrush current". Shop for a Uni-T 216C on Ebay. It runs around 80-85$ right now. Get one so you don't have to guess anymore.

 

[rmaddy]

For 3 320W panels you probably need a 150V SCC. I have 3 330W panels in series and they work very well with a 150V controller. The charge current of the controller depends on your system voltage. Are you planning 12V or 24V with the 6 batteries? 24V would be better. 48V would be even better but you need two more batteries (any making a 48V system with 12V batteries is far from ideal). At 24V you need a 35A or 40A controller. If you stay with 12V you need 70A-80A.

I can't help with a 240V inverter but you should post some more details about the pump. How many watts does it use when it runs? How often does it need to run?

 

[Roswell Bob]

Right at the start, I'd say your solar input would be totally inadequate. Using the 2X rule, I'd suggest you have ~4000W of panels to run your pump, or roughly four times what you have now. My pump needed 2280W to run, so I installed 4500W of panels. It works. My panels however are on rotating mounts, so they can face East in the morning and West in the afternoon. With this arrangement, I can pump water from 8:00AM till 4:00PM continously, without battery depletion.

Well pumps have very high starting surges, 4X or so, and most demand that surge for about a second or two. Keep in mind that most budget-model AiO units have next to no starting surge, maybe 2X for only 16 milliseconds or so. You should shop for an inverter that has a minumum of a 5 second starting surge. I've got a Schneider XW+6848. The Outback Radian is another viable choice. Both put out split-phase 120/240VAC.

I'm fairly certain the amount of power from array has very little to do with running a pump. Where did this 2x rule come from? If OP is running a pump continuous I will agree with the 2x. For normal residential use the battery will be supplying intermittent energy.

 

[mvonw]

We have 6 x 12v lithium batteries and 3 x 320w solar panels but we are stuck on what kind of inverter/controller to get that would run our 100ft deep 240v 3/4hp well pump & also use it for some 120v lights. We have a connection to our elec box to plug in a generator to run all of that but want to use solar since gas is so expensive now.

I was very much at the same decision point as you a few years ago. Got tired of running out of fuel, hauling fuel, etc.. If you want to go solar, I finally realized (as other members have pointed out) you need a ~5500 watt(ish) inverter and at least a few 48volt batteries. I have 3/4hp Aeromotor pump at 500ft. It draw about 20 amps at startup and 9 or so running. My Honda 240 volt 6500 watt generator sags pretty good when the pump starts.
Your other option is to get a new Grundfos SQflex pump. These will run on DC/AC and 120volt. You can run them on a much smaller system. I have heard that people run them on little portable 2200 watt honda generators. This is not a cheap option either, it's likely to cost $5-8k installed.

Solar is awesome, but it's far from free. I finally saved up enough to buy all the components I wanted, and now I'm starting to install it. Is your place full-time, or a cabin/camp type place? If you don't use it much and don't plan to keep the place for a long time, then it's probably not worth investment unless you just want the convenience of not having to constantly refuel.

 

[MichaelK]

I'm fairly certain the amount of power from array has very little to do with running a pump. Where did this 2x rule come from?

These numbers come from real-world experience actually powering a pump, as I said, for 8 hours per day.

 

[Wellbuilt]

I was trying to figure the well pump power for 5 years
After all that time I just dropped a SQF pump 700‘ in my well and got water .
The pump was 2100$ wire was 700$ sch120 pipe check valves pitiless adaptor wire stand offs 1000$
so less the 4000 bucks and all your problems are solved .
My pump uses 700 /900 watts runs off my 3600 watt inverter .
I can charge my system run the house and pump water on a 2800 watt generator all at once .

 

[Dlbecker]

I was very much at the same decision point as you a few years ago. Got tired of running out of fuel, hauling fuel, etc.. If you want to go solar, I finally realized (as other members have pointed out) you need a ~5500 watt(ish) inverter and at least a few 48volt batteries. I have 3/4hp Aeromotor pump at 500ft. It draw about 20 amps at startup and 9 or so running. My Honda 240 volt 6500 watt generator sags pretty good when the pump starts.
Your other option is to get a new Grundfos SQflex pump. These will run on DC/AC and 120volt. You can run them on a much smaller system. I have heard that people run them on little portable 2200 watt honda generators. This is not a cheap option either, it's likely to cost $5-8k installed.

Solar is awesome, but it's far from free. I finally saved up enough to buy all the components I wanted, and now I'm starting to install it. Is your place full-time, or a cabin/camp type place? If you don't use it much and don't plan to keep the place for a long time, then it's probably not worth investment unless you just want the convenience of not having to constantly refuel.

We are in a mobile home but the way things are going we want to be able to run things when the lights go out.

 

[mvonw]

We are in a mobile home but the way things are going we want to be able to run things when the lights go out.

Makes sense. Just don't fool yourself and think you can do it on the cheap (and be reliable).

 

[Roswell Bob]

These numbers come from real-world experience actually powering a pump, as I said, for 8 hours per day.

Yes, but you are misleading the OP unless he intends to run his pump continuously. Did OP say he was running continuous? The PV panel only has to supply the average power and not peak power in a typical residential application.

 

[MichaelK]

Yes, but you are misleading the OP unless he intends to run his pump continuously. Did OP say he was running continuous? The PV panel only has to supply the average power and not peak power in a typical residential application.

The OP is complaining about the cost of fuel, so that sounds like continuous to me.

But hey, what do I know? My only experience is how to pump about 265,000 gallons of water, solely via solar. Please outline your solar pumping experience?

 

[2022solarguy]

Yes, but you are misleading the OP unless he intends to run his pump continuously. Did OP say he was running continuous? The PV panel only has to supply the average power and not peak power in a typical

 

[2022solarguy]

I'm trying to find a 12v 220 inverter to run a well pump also..it would only be for emergency power outages..the Schneider seems to be sold out and the outback doesn't have 12v..is there any other 5000watt 220 inverters on the market. I have a ton of 12v large batteries that's why I want to stay with a 12v system

 

[rmaddy]

I'm trying to find a 12v 220 inverter to run a well pump also..it would only be for emergency power outages..the Schneider seems to be sold out and the outback doesn't have 12v..is there any other 5000watt 220 inverters on the market. I have a ton of 12v large batteries that's why I want to stay with a 12v system

12v 220 inverter

Does anybody make a 12v 220v 5k inverter ??

diysolarforum.com

 

[MichaelK]

We are in a mobile home but the way things are going we want to be able to run things when the lights go out.

It might be more realistic here to design a system for you that can power everything except your well pump. You've already got 6 batteries. Can they be wired in series? Please find out. What you could do is design a small 24V system that can keep the lights on and the refrigerator cold. Something that can make about 3kWh of power per day.

If you wire the six batteries as 2S3P, that would be what, 300Ah at 24V? What is the Ah capacity of just one battery? Get 50A controller like the Epever Tracer 5020AN, and you can wire the three panels in series to get ~115VDC. Then a budget sine-wave inverter, like a Samlex 24V 1500W inverter. If you want, you can use a rotating mount like this one, designed to hold three 300W panels. By rotating East to West, it will make you maybe 4.5kWh per day, even in December.

 

[2022solarguy]

Thanks for all the input and help on making a viable system but my main goal is to just run my well pump and furnace .I have smaller inverters for freezers and lights

 

[MichaelK]

I'm trying to find a 12v 220 inverter to run a well pump also..it would only be for emergency power outages..the Schneider seems to be sold out and the outback doesn't have 12v..is there any other 5000watt 220 inverters on the market. I have a ton of 12v large batteries that's why I want to stay with a 12v system

Just because you have 12V batteries doesn't mean you have to limit yourself to 12V. Wire them in series to get either 24V or 48V. Then you'll have access to higher end split-phase inverters that put out both 120V and 240VAC. How big is your well pump? Did you reference the chart above?

Where are you shopping that they are sold out of Schneider? You might want to look at these guys...

Schneider Electric Conext SW4024-120/240 Inverter/Charger - RES Supply

Free Shipping! Schneider Electric Conext SW4024-120/240 Inverter/Charger, 4000W, 120/240VAC, 50/60Hz, 30A Transfer, 24VDC, 90A Charger, RNW8654024

ressupply.com

 

[2022solarguy]

Cool thanks, I will check that link out..im not sure what hp my pump is or what it draws..im at ground zero here.i see your chart. Ill have to crawl under the steps and see what I can find tomorrow ..I really could wire them all in series if needed..I didn't want to have to take them out of the trucks...could a guy have a 48v bank made in series then tie a string of 12v in parallel behind them???

 

[MisterSandals]

then tie a string of 12v in parallel behind them???

Not sure what you mean "behind them" but folks normally get a 48V -> 12V converter for their 12V needs.