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MPP Solar Pump Inverter / Experience with deep well, 230VAC single phase 3 hp pumps

snoobler

snoobler

Solar Honey Badger
Joined
Jul 10, 2020
Messages
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Location
HBR, AZ
My neighbor has a beastly well pump that requires surge current equivalent to about 14kW. He runs it with his 24kW diesel generator. It's a deep well (700') Grundfos pump classified as 3hp/single phase 230VAC. 12A run, 60A surge

A recent solar upgrade has made the genny necessary only for pumping water into his 2k gal above ground storage tanks.

MPP Solar offers a SP-2.2K LS Solar Pump Inverter


Soft start available
Provisions for generator running
Run current of 14A for single phase

This and another 3kW of array seem like they may do the trick.

I've sent an email to MPP Solar, but I thought I'd check here too. Thoughts?
 
your European/rest of the world power spec? IE this is not NA? (230v single phase is what you list unless that is a typo)
 
the mpp that you linked only does high power output (that I assume you would need for that startup load) in 3phase.

you might squeeze by on the 7.5kw (15A max output) but as this is china product i take those specs with a 20% grain of salt meaning If it was my recomendation to my buddy I wouldnt be spec'n anything below the 11kw 22A version (which is 3phase only)
 
Last edited:
Some considerations:
  1. Guiding the Lilly. Why buy a device capable of either single or 3-phase pumps when you have a single phase pump? Paying for spec you will never use?
  2. Two tasks. I am assuming that you have two tasks in mind: the genset getting water out of the well into the storage tanks, the inverter pumping water from the storage tanks to your house. For the avoidance of doubt, you cannot simply combine the two outputs (although this inverter does have a backup AC input).
  3. Two systems. Why have two supply systems, when a single system could be designed i.e. supply pump from the well and into the house. Seems like an unnecessary single point of failure e.g. if the genset runs out of fuel. But I suppose you can say the same thing about running out of sun!
 
1) because devices of this nature are uncommon and incredibly expensive. Comparable devices that I can locate cost 10X+ over the Ali price of this unit.
2) No. One task. Run the deep well pump with solar. Use the Genny as backup if insufficient sun. The main goal is to eliminate the need to run the generator except for backup purposes.
3) It is extremely common in deep well situations (that require so much power to pump) to have above ground storage. In this case, there is a separate 1/2 hp jet pump run by the off-grid system to supply pressure to the house drawing from the 2000 gallons already above ground.
 
tictag said:
  1. Two systems. Why have two supply systems, when a single system could be designed i.e. supply pump from the well and into the house. Seems like an unnecessary single point of failure e.g. if the genset runs out of fuel. But I suppose you can say the same thing about running out of sun!
Click to expand...
This doesnt work for his already inplace installation of a 700' deep well and an above ground 2K gal storage tank. The benifit of this is the inground well pump only has to run once a week or month and because of its low duty cycle lasts a LONG time. Meanwhile the constant on/off 40psi house pump is easy to replace and inexpensive.
 
tictag said:
Why buy a device capable of either single or 3-phase pumps when you have a single phase pump? Paying for spec you will never use?
Click to expand...
Earlier someone mentioned VFDs which might solve the startup problem of a deep well pump. I don't how expensive VFDs are, but I think the advantage was that it could be powered with 120 v single phase.
 
Ahh, looks like I misunderstood ... I thought you were planning to continue using the genset for one task, the inverter for something else. Apologies.

1) So this device (with the additional functionality) is actually cheaper than comparable devices. Got it.
 
Yep. And to VFD, what little I understand suggests that most of these are designed to produce 3 phase output from difference sources as 3 phase motors respond well to them. MOAR RESEARCH!
 
snoobler said:
My neighbor has a beastly well pump that requires surge current equivalent to about 14kW. He runs it with his 24kW diesel generator. It's a deep well (700') Grundfos pump classified as 3hp/single phase 230VAC. 12A run, 60A surge

A recent solar upgrade has made the genny necessary only for pumping water into his 2k gal above ground storage tanks.

MPP Solar offers a SP-2.2K LS Solar Pump Inverter


Soft start available
Provisions for generator running
Run current of 14A for single phase

This and another 3kW of array seem like they may do the trick.

I've sent an email to MPP Solar, but I thought I'd check here too. Thoughts?
Click to expand...

I am so jealous right now.

So what was the final verdict? What was MPP's recommendation?

Also, the above ground storage tank ... is it on ground level or is it elevated above the home, dwelling, barn?

What is the terrain? Flat ground, hilly, mountainous?
 
MPP Solar: "No."

You might check your pump specs with watts247.com as I believe they offer those as well.

Ground level with the base about 4' below the house. They have a 1/2hp jet pump and a pressure tank to provide pressure to the house.

He's acquired a rebranded Sigineer 6kW/24V inverter with 18kW surge. Both Sigineer and Electric Car Parts Company (distributor) confirmed it should work. He's waiting for his well pump guy to do the wiring.
 
snoobler said:
My neighbor has a beastly well pump that requires surge current equivalent to about 14kW. He runs it with his 24kW diesel generator. It's a deep well (700') Grundfos pump classified as 3hp/single phase 230VAC. 12A run, 60A surge

A recent solar upgrade has made the genny necessary only for pumping water into his 2k gal above ground storage tanks.

MPP Solar offers a SP-2.2K LS Solar Pump Inverter


Soft start available
Provisions for generator running
Run current of 14A for single phase

This and another 3kW of array seem like they may do the trick.

I've sent an email to MPP Solar, but I thought I'd check here too. Thoughts?
Click to expand...
So is this supposed to do a ramped variable freq start of the single phase pump?
 
DThames said:
So is this supposed to do a ramped variable freq start of the single phase pump?
Click to expand...
Nope, won't work. Needs a 3-phase motor.
And a VFD will require 240V (or 208V) to supply it. If there are any 120V, will be low horsepower.
Grundfos has pumps with built-in VFD, and pumps which run direct off PV. Not sure if any that can lift water 700'

My solution (like always) would be Sunny Islands. "When all you have is a hammer ..."
Two SI-6048 2s1p would put out 240V with 22kW surge 3 seconds, 11.75 kW continuous at ambient, 150A surge for 60 ms (not necessarily enough).
Four 2s2p would put out 44 kW surge, 23kW continuous. That should do the job.
But it will set you back $10k at today's prices, a few times cost of a deep well pump. So alternative pumps especially PV direct should be explored.

18 kW surge, 75A ... sounds like that should do it, depending on how long the surge lasts.
Something tells me a deep well has a foot valve, and therefore no unloader. May be more difficult to start than a surface pump or air compressor. I could conceive a more complex design that did unload during starting.
 
snoobler said:
ONE of their units works with 240VAC single or 3-phase:

SP2.2LS 2.2kW 2 and 3 PHASE Well Pump Inverter Single or 3 Phase selectable, Batteryless – Watts247 Wholesale

watts247.com watts247.com

That's the one I was exploring.
Click to expand...
Do you already have a well pump?

I don't believe single phase can be soft started, will always require a significant surge. "soft starters" might ease the surge somewhat, but nothing like slowly spinning up a 3-phase pump.

Looking briefly I didn't find 3-phase pumps. Pretty sure they exist, but maybe not common for residential size. I used to see a pump for monitoring wells that fit in a 2" casing, ran off an inverter from 12V battery.
Any of the pumps I did see for deep wells in the 500' to 1000' for so range produced way more gallons of water than a household needs. If one was available in tiny displacement and low horsepower, putting out 2 gpm (1200 gallons in 10 hours), that would be ideal.

Kind of doubt that controller can run a single-phase motor variable speed. Probably the 150% oversized PV array runs the pump while production is clipped. I think a 3-phase run at variable frequency could run earlier and later, with variable water flow. Limited by how slowly it can rotate and still push water out of the well.

See what Grundfos has for PV direct, if it works for your depth. That would be variable speed. They also offer varying speed to maintain pressure with domestic use. But of course, filling a tank as fast as PV allows and then booster pump off batteries at night would be better for off-grid. Actually, having PV for your household power, and varying pump speed to use surplus power would be best.
 
DThames said:
I have 240v single phase pump. It would be nice to have an inverter that can handle it but for standby reasons a high dollar solution is not worth it.
Click to expand...
I would guess $2k to $5k for a quality inverter. Cheaper solution would be tank and 12V booster pump for fixed quantity of water, or gas generator for longer power outages.

But if that $500 solar pump inverter Snoobler linked does that job, that and up to 4kW/$1000 of PV could be another option.
 
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