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Best Inverter for deep well pump

The only reason why I run my generator is to pump water and other heavy loads. I've toyed with the idea of replacing my perfectly fine, 240 VAC deep well pump with a dreamy, and expensive, grundfos soft start pump. I'm leaning towards going with a 24 vdc in, 240 VAC 5,000 watt invertor to run the existing pump and cabin when I've grown my solar farm enough to support it.
Which inverter specifically?
 
Which inverter specifically?
Inverter or possibly inverters, for example I like what Will did here with two MPP inverters connected in parallel, in phase with each other to make 240 VAC at 4,800 watts which would be plenty for me.
 
My understanding is the Mpp inverters would be a very poor choice for running a well pump. I just watched another YouTube video of a guy testing a 48V Mpp 5000. It could not start his miter saw, which would not be as high a wattage as my well pump. You will be far better off getting an Outback Radian, or Schneider XW, both serious low-frequency inverters. For a well pump, you really need to focus your attention on the surge watts of whatever unit you buy.
 
My understanding is the Mpp inverters would be a very poor choice for running a well pump. I just watched another YouTube video of a guy testing a 48V Mpp 5000. It could not start his miter saw, which would not be as high a wattage as my well pump. You will be far better off getting an Outback Radian, or Schneider XW, both serious low-frequency inverters. For a well pump, you really need to focus your attention on the surge watts of whatever unit you buy.
I agree. I watched Wills video with interest but realized that these inverters are high frequency with very little surge capability. As I understand it you need to up-size the low frequency inverter so that any surge load is within the continuous rating of the inverter. That negates any cost advantage of the high frequency inverter. I would love to own either the Schneider or the Outback but the cost was a big factor. All I really need for continuous power is 4000 watts. both the Schneider and the Outback 4000 watt offerings fell just a tad short in the surge capability for my well pump. Either one of these would have fit in my budget. Unfortunately the next step up in size bumped the price beyond what I could justify.
I settled on the Aims 4000W UL 458/1012/1741 CSA inverter. This Inverter boasts a 30 second 12000W surge which handles my Well pump. It costs a bit more than the standard 4000W version. I think it will work for me as a Backup power source.

 
I never even considered that a pair of beefy looking MPP inverters creating a combined of 4,800 watts could falter in the face of surge current even if it's less than 4,800 watts. This is valuable information to consider when growing my solar power system, thank you all.

Size of Pump MotorRunning WattageStarting Wattage
1/3 HP750 to 8001,500 to 2,400
1/2 HP900 to 1,0501,800 to 3,150
3/4 HP1,500 to 1,8003,000 to 5,400
1 HP2,000 to 2,4004,000 to 7,200
1.5 HP2,500 to 2,8005,000 to 8,400
2 HP3,750 to 4,0007,500 to 12,000
3 HP5,000 to 5,50010,000 to 16,500
5 HP7,500 to 8,00015,000 to 24,000
7.5 HP10,000 to 11,00020,000 to 33,000
10 HP15,000 to 16,00030,000 to 48,000
 
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I never even considered that a pair of beefy lookig MPP inverters creating a combined of 4,800 watts could falter in the face of surge current even if it's less than 4,800 watts. This is valuable information to consider when growing my solar power system, thank you all.

Size of Pump MotorRunning WattageStarting Wattage
1/3 HP750 to 8001,500 to 2,400
1/2 HP900 to 1,0501,800 to 3,150
3/4 HP1,500 to 1,8003,000 to 5,400
1 HP2,000 to 2,4004,000 to 7,200
1.5 HP2,500 to 2,8005,000 to 8,400
2 HP3,750 to 4,0007,500 to 12,000
3 HP5,000 to 5,50010,000 to 16,500
5 HP7,500 to 8,00015,000 to 24,000
7.5 HP10,000 to 11,00020,000 to 33,000
10 HP15,000 to 16,00030,000 to 48,000
Good chart but it may be a little optimistic. My well pump runs at 2000W but start surges to 9000W. Actual measured.
 
I never even considered that a pair of beefy looking MPP inverters creating a combined of 4,800 watts could falter in the face of surge current even if it's less than 4,800 watts. This is valuable information to consider when growing my solar power system, thank you all.

Size of Pump MotorRunning WattageStarting Wattage
1/3 HP750 to 8001,500 to 2,400
1/2 HP900 to 1,0501,800 to 3,150
3/4 HP1,500 to 1,8003,000 to 5,400
1 HP2,000 to 2,4004,000 to 7,200
1.5 HP2,500 to 2,8005,000 to 8,400
2 HP3,750 to 4,0007,500 to 12,000
3 HP5,000 to 5,50010,000 to 16,500
5 HP7,500 to 8,00015,000 to 24,000
7.5 HP10,000 to 11,00020,000 to 33,000
10 HP15,000 to 16,00030,000 to 48,000
This is why having numbers in hand BEFORE you start buying things is so important. BTW, I would say your chart above is overly optimistic. I have a 1hp pump, and it's MEASURED starting surge is 38A X 240V =9120AV. After getting my numbers, I was on the phone with each company's engineers to talk to them about what their units could power.

It's likely that four of your Mpp inverters couldn't start my pump. This is why the low-frequency inverters cost so much more. Because they are actually designed for serious off-grid loads, not just your TV.
 
This is why having numbers in hand BEFORE you start buying things is so important. BTW, I would say your chart above is overly optimistic. I have a 1hp pump, and it's MEASURED starting surge is 38A X 240V =9120AV. After getting my numbers, I was on the phone with each company's engineers to talk to them about what their units could power.

It's likely that four of your Mpp inverters couldn't start my pump. This is why the low-frequency inverters cost so much more. Because they are actually designed for serious off-grid loads, not just your TV.
HOLY TOLEDO, i didn't even know that low frequency and high frequency inverters existed, once again my hats off to you Michael for sharing this information and everyone else that takes the time to share what they know and of course ultimately Will for hosting this forum.

Thank You Thank You Thank You
 
Why is it that magnum inverters are never mentioned in threads like this? (not being facetious). I use a magnum and have had no problems to date (4448 pae) but I am always looking to learn.
 
11+ years running a 240VAC 1/2hp, 4" well pump, 160lift off of a XW6048 inverter
It's a native split phase 240VAC inverter, 6kw cont rated, easily handles the motor starting surge
(as must the battery internal resistance, cables and interconnects)
 
11+ years running a 240VAC 1/2hp, 4" well pump, 160lift off of a XW6048 inverter
It's a native split phase 240VAC inverter, 6kw cont rated, easily handles the motor starting surge
(as must the battery internal resistance, cables and interconnects)
those are pretty solid from what I have seen, as are the outback and magnums. any low frequency inverter is going to handle the strain better than a high frequency. the other thing to consider is that a modified sine wave low frequency inverter is cheaper than a Sine wave low frequency and might do the job as well, but this is something that you should consult with the pump makers engineers (not sales reps) as to if they would be happy with modified sine wave.
 
Running a motor ( the larger, the worse) from a mod sine inverter will greatly shorten the lifetime of the motor. The harmonics generate about 20% more power loss (HEAT) in the motor windings, and that extra heat comes from the PV & batteries.
 
Running a motor ( the larger, the worse) from a mod sine inverter will greatly shorten the lifetime of the motor. The harmonics generate about 20% more power loss (HEAT) in the motor windings, and that extra heat comes from the PV & batteries.
there ya go figured someone might have better knowledge about that. I run all my stuff off of my magnums which are all sine wave so I have no issues, but i originally chose the sine wave versions so that I could be guaranteed to run any and all electronics without fear. as the motors came later I never even bothered to study up on that bit as my inverter power was as clean (if not cleaner in some cases) than what came out of the wall.
 
Looking for advice (preferably from someone who has actually done this) used an inverter to power my cabin. My primary draw is a 240 volt 1hp well pump @ 500 feet depth. I have been running it for years with a 6500 watt Honda generator, but even with that the generator pulls pretty hard when the pump kicks in. I would guess I need an inverter that would handle 4000 watt surges, at least.
Is one 48 volt 240 volt inverter better, or two 120 volt inverters ganged together better/more advantageous?
You'll need an 8 kw inverter. Not that the pump uses that much when running but the surge on a 1hp pump is massive to start it up especially @ 500 ft & you'll need a low frequency inverter. They have some head room to put out usually double the rating briefly whereas a high frequency inverter will not deliver much past it's rating. I know this 'cuz I have a 120v 1/2 hp shallow 70 ft well & it sometimes shuts down my low frequency 4kw inverter on occasions.
 
I've been running my well pump solely off of solar for three years now, and I'm very pleased with the results. I have a 1hp Grunfos 240VAC pump, that's similar to yours. I would disagree with the 24V suggestions given above. Using a clamp meter on the control box, I found the my wellpump draws about 10amps while running, but 37-38amps right at startup. This was measured with a Fluke meter with the ability to measure "inrush current". That's 9000+ watts at startup. I install a 48V Schneider XW+6848 to power my pump, and it has performed flawlessly the last three years. My panels are on rotating mounts, so I can face them eastward in the morning, then turn west in the afternoon. With my panels, I can keep the pump running with no battery depletion from about 8:30am till 4:30pm. If sticking with 24V is important, one alternative that might work is a Dual-Conext SW4024s wired in parallel. It's also a 120/240VAC inverter, but when two are linked in parallel, they will match phases and double output.


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Michael what batteries and solar panels are you using?
 
As long as you're talking about expensive, serious low-frequency inverters to run a well pump, consider SMA Sunny Island.
European model is 220V, US is 120V so you need either a transformer or two of them.
You can connect 3 for 3-phase (good idea for running motors), or four for more wattage single phase.
Each one produces 5750W continuous, 11kW surge for 3 seconds.

At $5000 each (msrp) they aren't cheap. But you can probably find new in the box liquidation units around $2000.

 
First off, I have 0 experience with wells this deep, I have little hands on experience with wells in general and the 1 one well I observed a guy struggling with was an old girlfriends dads from almost 30 years ago.

He was having issues with pumps failing in his 200ish foot deep well. He was hell bent on having a big pump that could supply shower after shower in a house with 4 girls, him and his wife.

His well didnt have adequate recovery rate to supply what he was trying to do and he was a moron and was getting poor advise.

After the first failure I had suggested installing a very small volume pump down the hole to fill a large atmospheric holding tank on the surface, then use a simple low pressure pump to supply the 45+ psi to the house. After several thousand dollars worth of service calls trying to make a 1 pump system work this is what was done. I broke up with his daughter a few months later but it did work without incident while I was around.

2 pumps has several advantages:
  • A low volume down hole pump reduces ground water depression and is better for the well itself as it will draw in a lot less sediment and debris.
  • Not adding the service pressure to the head pressure greatly reduces strain on the down hole pump and pipe.
  • Even at 0.25gal/min you will get 360 gallons in 24 hours making even a low producing well viable.
Just some food for thought
 
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