Adding a 240V inverter for well pump

[Rick_in_MT]

Apologies if this is close to similar postings but some of the numbers are different.

I currently have a (very small solar setup) with a 400AH battery bank with a 12v 40A Renogy charge controller and 2000W Renogy inverter for emergency use. I'd like to add a 240V inverter for my 80-ft well pump. The pump is HERE. It is 3/4 HP 230V 2-wire single-phase. I'm no electrician but I've done plenty of my own 120V work. However, this is a bit outside my comfort zone.

The pump only runs 4 or 5 times a day to refill our pressure tank and the well is only 80 ft deep and about 30 or 40 feet from the house. Again, this is for emergency use only, like the rest of the solar setup.

My question is, after some searching I've found this inverter and the manufacturer answered my email that it will be sufficient.

"Sigineer Power 3000 watt Pure Sine Power Converter changes 12Volt to 120/240Vac Pure Sine Wave output.
This 3KW 12V Pure Sine Power Converter is more than just your daily inverter. It is a three-in-one product:
It is an inverter that converts 12V DC (direct current) power into 120/240V AC (alternating current) electricity to power tools and appliances.
A built-in 30 amp transfer switch will automatically switch between shore power and battery-bank power within 10 mili seconds."

Of course, they want to make a sale, plus it's from China. Cost is a problem as we're retired and my hairbrained schemes are done on a shoestring. I read some of the other discussions and the inverters they mentioned are astronomically out of my range.

Otherwise I'll be hauling water from the creek. Am I out of luck?

Thanks,

Rick

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[BentleyJ]

It would be prudent to test the inrush current with a clamp-on ammeter that has a peak hold or surge current setting. The specs on the inverter are good (assuming they are accurate) Taking the worst case scenario, a full 9,000W surge would require 720A+ at 12.5V.
That is a massive amount of current. I'm betting the existing wiring and fusing is not going to support that. Not to mention 720A would also be a 1.8C discharge rate, although very short duration, maybe ok for your battery?

 

[Rick_in_MT]

This is the current setup. The switch box on the wall is for the pump, I'd probably mount the inverter on the wall below it, or on a shelf below it. None of the existing wiring would be part of the new inverter, though.

 

[MichaelK]

You're the same Rick that was asking the same question on Survivalist Boards? You really have to get the same answer. So, with....

"The Franklin Motor requires a pure sinewave power source because there is an electronic BIAC Switch in the motor which takes the start winding out of the circuit when the motor gets to running RPM. The two-wire motor does not have a start capacitor so the inrush at start up is higher than the 3-wire motor with a control box. The inverter will have to be capable of producing 40.7 amps or about 8200 watts for about 1/10th second each time the motor starts."

My advise to you is just completely forget Sigineer, and completely forget 12V. It just ain't gonna work! Neighbor down the road has a 24V Aims, (made by Sigineer), that can't be trusted to start his pump.

What you need to make this work is a quality 120V/240V inverter like a 6848 XWPro, or an Outback Radian8000, with at least 3000W of panels. Time to suck it up and accept reality.

 

[rhino]

I replaced my 240V well pump years ago with a 120V Grundfos for same price as that inverter at the time.. and Grundfos has no inrush so you'd likely be able to run it with your existing inverter.

 

[dragondoom295]

Can you rig up a capacitor bank to handle the inrush current? Then slowly charge them back up if the pump is only on three or four times a day? Or a soft starter?

 

[scoharri]

Of course, they want to make a sale, plus it's from China.

Everything is from China

 

[Rick_in_MT]

OK Got it.

You're the same Rick that was asking the same question on Survivalist Boards? You really have to get the same answer. So, with....

"The Franklin Motor requires a pure sinewave power source because there is an electronic BIAC Switch in the motor which takes the start winding out of the circuit when the motor gets to running RPM. The two-wire motor does not have a start capacitor so the inrush at start up is higher than the 3-wire motor with a control box. The inverter will have to be capable of producing 40.7 amps or about 8200 watts for about 1/10th second each time the motor starts."

My advise to you is just completely forget Sigineer, and completely forget 12V. It just ain't gonna work! Neighbor down the road has a 24V Aims, (made by Sigineer), that can't be trusted to start his pump.

What you need to make this work is a quality 120V/240V inverter like a 6848 XWPro, or an Outback Radian8000, with at least 3000W of panels. Time to suck it up and accept reality.

I'm aware I'm "the same Rick"-- I found this forum and it seemed better suited to the subject. Thanks for the advice.

 

[Ampster]

Grundfos has no inrush so you'd likely be able to run it with your existing inverter.

His well is only 80 feet so he might be able to pull the pump out and rewire a Grundfos and still be less expensive than a bigger Sigineer or one of the inverters mentioned that can handle the current surge.

 

[OzSolar]

Well pumps are always a challenge. Once you've got a big enough system to reliably start a standard well pump pretty much everything else is easy.

As has already been mentioned you probably should look into a different well pump. Not only could it be run from your existing inverter but also a small petrol generator or portable battery inverter (like a jackery or bluetti) could do it. This is the most resilient set up for pumping water if the grid is down.

 

[dragondoom295]

I know it isn't a solar option, but if you are just looking for emergency use, you could always rig up a simple hand pump well. Look up slap shot well hand pump. You just need a foot valve some PVC and rig an internal piston with a check valve. You can even put a DC motor on it run by solar. Just a thought.

 

[sunsurfer]

I replaced my 240V well pump years ago with a 120V Grundfos for same price as that inverter at the time.. and Grundfos has no inrush so you'd likely be able to run it with your existing inverter.

I was just thinking with such a shallow well, I would swap out the pump and go with the existing inverter/setup. I've ran a grundfos SQ 120v on a 12v 2,000w HF inverter with no issues. Pumps $800-$900, how much is an entire 24v or 48v setup to run the existing setup? LF inverters are not cheap. Of course, that was installing the pump myself. Not sure of OP capabilities in that area.

seems other agree, pump swap may be the easiest solution.

 

[Lighthouse Beacon]

You’ll have to spend 1k-2k on a bigger inverter

 

[Rick_in_MT]

It does sound like swapping out the pump is the best option. But I'll have to find a well guy or plumber who can do it.
I went to the Grundfos site and it's all Greek to me. Better let a professional do it.
Thanks so much, guys. You're keeping me pointed in the right direction.

 

[tomy2]

I replaced my 240V well pump years ago with a 120V Grundfos for same price as that inverter at the time.. and Grundfos has no inrush so you'd likely be able to run it with your existing inverter.

I did the same thing , the pump only draws 6-700 watts, no start up surge. They are now listed for twice the price that I paid two years ago. Shop around! the pump is down 130', about the max for a 110V.

 

[sunsurfer]

It does sound like swapping out the pump is the best option. But I'll have to find a well guy or plumber who can do it.
I went to the Grundfos site and it's all Greek to me. Better let a professional do it.
Thanks so much, guys. You're keeping me pointed in the right direction.

I would consider one of their basic SQ soft start series (no controller). At that elevation, a 120v 10 GPM would pressure your house no problem and likey use less then a 1000 watts. I'm using a 10 GPM SQ thats rated for 160' head height and pull about 1000 watts. My water level is at 150' but I am pumping to a holding tank then pressuring from their. A rating for about 100-120' head height(includes building pressure) might work for you depending on water height. You need to consider how much volume you want/need.

The SQs part numbers are based of desired GPM. 5, 10, 15, etc.... Then you selected pumping height that includes the pressuring.

Search

Search

www.grundfos.com

 

[sunsurfer]

I did the same thing , the pump only draws 6-700 watts, no start up surge. They are now listed for twice the price that I paid two years ago. Shop around! the pump is down 130', about the max for a 110V.

Hey Tomy, I use to live in Paso. Lots of wells getting sucked down from the vineyards. I'm in Missouri now. I have an 10 SQ5-160 placed down about 200'. My water is at 150'. I'm running 1.25" poly for drop pipe. I'm pulling about 1000watts. You can go much lower on 110v but you have to loose some GPM.

 

[tomy2]

Hey Tomy, I use to live in Paso. Lots of wells getting sucked down from the vineyards. I'm in Missouri now. I have an 10 SQ5-160 placed down about 200'. My water is at 150'. I'm running 1.25" poly for drop pipe. I'm pulling about 1000watts. You can go much lower on 110v but you have to loose some GPM.

Definitely a lot of wells went dry in mostly east paso. After seven years of drought, I was worried, but when they pulled the old pump, the water was at 125'. And I misspoke, the pump is at 160', it may be the same one as yours. Have a good Holiday. Oh, and if you haven't been in Paso Robles for a few years, it has gone Gucci. Lots of upscale hotels and restaurants, wine tasting everywhere. No more cow town, unless you're looking for it.

 

[tomy2]

Pumps $800-$900

I paid a little less, but now it is listed at about $2k.

 

[sunsurfer]

I paid a little less, but now it is listed at about $2k.

dang, must be from a proud driller/installer for that price. Here is the 110' 120v 10 GPM for under $867 with shipping. This is the company I got my pump and wire from (aquascience.net). The 160' always seems to be back ordered or delayed. Its a very common one to buy.

Grundfos 10SQ05-110-115V, 10GPM, 1/2HP, 115V, 2 Wire, 96160166, 3" Stainless Steel Submersible Well Pumps

By the way, Grundfos does not have support. You are left with whom you buy from. By some serious effort and luck, I have actually talked with one of their engineers trying to get a question answered. It was a miracle.