Grundfos SQ pumps should be stickied to the top of this catagory.

wild01

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Grundfos SQ series ac pumps are the only pumps I've ever run across that run perfectly on just about ANY inverter over 1000w. if planning on running a well pump offgrid they are the only system I've ever seen that JUST WORKS. (for domestic use, irrigation is a different animal) Everything else requires overly complicated setups that often pump every gallon of water.

I think they should be a sticky in this catagory because every time I've recommended one to someone it was as a REPLACEMENT for the well pump they had already bought... that didn't work offgrid.

sq model numbers look like this 10SQ05-160 10=gallons per minute 05=1/2hp-160=rated head. their 1/2hp pumps come in 120 and 240 their larger pumps only in 240.

to determine what pump to buy, first decide how many gpm you want/need. I've personally never had a need for over 10gpm even in a 4 bath house. grundfos goes over 30 on the sq line. Next number you'll need is your static water level in the well. to determine rated head pressure needed add the depth to static water level in your well plus your desired water pressure. standard well pressure switches are 20/40 30/50 and 40/60 so if you had a well with a 70 foot static level and wanted 60psi @ your faucet your minimum head pressure would be 130. I like to add about 30 or more to this number as a margin of error. in this senario the above listed model would work fine. if the well was deeper you would need a higher head rated pump.

5gpm models
5 SQ15-450 (1)
5 SQ10-410 (1)
5 SQ10-360 (1)
5 SQ07-320 (1)
5 SQ07-270 (1)
5 SQ07-230 (1)
5 SQ05-90 (1)
5 SQ05-180 (1)
5 SQ05-140 (1)

10 gpm models

10 SQ15-330 (1)
10 SQ10-290 (1)
10 SQ07-240 (1)
10 SQ07-200 (1)
10 SQ05-160 (1)
10 SQ05-110 (1)

15gpm models
15 SQ15-290 (1)
15 SQ10-250 (1)
15 SQ10-220 (1)
15 SQ07-180 (1)
15 SQ07-150 (1)
15 SQ05-70 (1)
15 SQ05-110 (1)

I have no affiliation with grundfos just wish someone had mentioned them to me when I was staring out offgrid
 

OzSolar

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I would not disagree with that! We've done several SQ and SQFlex jobs. They are impressively engineered and built. The inverters that sounded like they were about to self destruct when the standard well pump kicked on don't even grunt with the SQ. Doubled GPM in most cases. Ideal for off grid homes.
 

newbostonconst

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I agree, I have a SQ5 (2-wire) that easily runs off a 4k inverter with other loads at the same time no problem.

Having the 2-wire option you can also add a drive to very the frequency for tuning also for variable output.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
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Rural NE Ontario Canada
I have an SQ5 120V SoftStart which was highly recommended to me by my Well Driller who actually does a lot of offgrid wells. I was already considering Grundfos due to past experience with their pumps. It starts at 550W and stages up to 1100W by the time it reaches 50PSI cutoff, never ever notice water pressure drop or increase, it is always smooth & consistent unlike many other pumps.

I even ran it with a Mod Sine 1500W "Car Inverter" a couple of times just after it was installed to test the water pressure output and even that craptastic inverter dealt with it without a blink or noises.

For the curious:
Pump is at 260' depth, pushes to 50Gal pressure tank in the pumphouse. From pumphouse to the house is another 75' distance. I also have two Filters on the water lines after the pressure tank, one for sediments* and then a fine particulate filter. These are part of the RainFresh Filtering system.
* A sediment filter is always important on a New Well and in my instance, I had it drilled with a Cable Pounder drill as opposed to a Bore Drill. While a Pounder is slower, it fractures the rock as part of its process which improves overall water flow & recovery, but a side effect will result in more sediment flushing into the well for the initial "break in" period of about a year. Bore Drilling is Faster but does NOT fracture the rock and they typically have to go 10-25% deeper to achieve the same recovery rates (pending on rock type). Drilling Costs are BY THE FOOT so fewer feet down = less cash outlay = happier wallet.

SQFlex Pumps​

Suitable for:
  • Solar water solutions
  • Community water supply
  • Livestock watering
  • Solar boosting and water supply solutions
Renewable energy submersible pumps with build-in inverter for solar, wind and AC powersource. Runs on both AC and DC voltage

AGREE - This should be Stickied.
@svetz what do you think ?

LINKS:
SQ Series of Pumps:
https://product-selection.grundfos.com/products/sq?tab=products
SQFlex Series: https://product-selection.grundfos.com/products/sqflex?tab=models
Rainfresh Filtering Systems: http://rainfresh.ca/

Videos:
 

svetz

Works in theory! Practice? That's something else
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...AGREE - This should be Stickied....@svetz what do you think ?
I don't know enough about the hardware end of things, but I suspect if everyone agreed there was only one real solution Will would probably go for it. I know in general the thought is to not give preferential treatment to any one/two vendors because things change over time. For example, KiloVault has a great system, but at a price. That's why Will's links to products change all the time as he finds something newer/better or an old good supplier starts having QC problems... he updates his pages rather than have to worry about forum changes. Usually I just refer folks to those pages, as long as Will keeps them updated the thread information is timeless.

I'd have to ask though, why not a DC pump to eliminate the inverter efficiency losses and surge/size/cost issues?
 
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wild01

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I don't know enough about the hardware end of things, but I suspect if everyone agreed there was only one real solution Will would probably go for it. I know in general the thought is to not give preferential treatment to any one/two vendors because things change over time. For example, KiloVault has a great system, but at a price. That's why Will's links to products change all the time as he finds something newer/better or an old good supplier starts having QC problems... he updates his pages rather than have to worry about forum changes. Usually I just refer folks to those pages, as long as Will keeps them updated the thread information is timeless.

I'd have to ask though, why not a DC pump to eliminate the inverter efficiency losses and surge/size/cost issues?
Line loss. There are other solutions besides a grundfos sq. But most are overly complicated. Low voltage dc suffers from extreme line loss at depths over 100 ft. Most other offgrid systems are either double pump systems that fill a holding tank or some other convoluted setup, or people end up buying an inverter 10x the size they need because nothing else will push their pump. The sq isn't the only solution, but it will usually be the simplest and cheapest. I've been offgrid 20+ years. I've had the same 1/2hp sq pump down my well for the last 18, I've helped guide multiple neighbors to use the same tech, because most local well drillers will sell them whatever pumps they get cheapest and never consider ongrid vs offgrid. When I bought my house the previous owners where using a generator to power the well pump to pump into a cistern that they then used an rv pump to pressurize the house. This was the standard setup on hundreds of houses in the area. It was wasteful high maintenance cumbersome and expensive. 1 $500 sq pump eleminated it all
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
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Rural NE Ontario Canada
I'd have to ask though, why not a DC pump to eliminate the inverter efficiency losses and surge/size/cost issues?
The SQFlex models are AC/DC Grundfos has been ahead of that for years.

Yes there are other brands that compare but NOT that many.
Many people fall over water pumps and what to select and what is more efficient which is REALLY important in an off-grid or any "energy frugal" setup.
This is a question we cover a LOT in the Cabin, Tiny Home, Homesteading forums (I belong to a few) and it also belongs here as many here going solar want/need to cut their power usage "conservation being cheaper than generation & storage".
 

mvonw

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Sep 23, 2019
Messages
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I just ordered a Grundfos for my cabin. It’s hard replacing a perfectly good 240 volt AC deep well pump, especially given the cost, but the flexibility of being able to power this off a small generator is so appealing, I couldn’t resist. I hope it lasts
 

opticalcarrier

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Feb 25, 2021
Messages
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very cool info there, has anyone seen the comparable decoder for their submersible 48VDC pumps?
EDIT TO ADD: I did find a great chart about halfway down this page:

Looks like Ill be getting that 11 SQF 2
 
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wild01

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Messages
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very cool info there, has anyone seen the comparable decoder for their submersible 48VDC pumps?
EDIT TO ADD: I did find a great chart about halfway down this page:

Looks like Ill be getting that 11 SQF 2
What's your application?
 

wild01

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A well pump connected directly to battery, bypassing critical loads panel so I never take AC startup surge hit when the pump turns on
Ok. So the reason I ask this is because there are very few applications where I personally find the flex pumps to be cost effective.
They are great products but can be up to 5x as expensive as an SQ. Also the standard sq has no startup surge.
What is your well depth, static water level desired gallons per minute and desired house pressure
 

opticalcarrier

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thats the problem its DEEP. 400ft to the the aquifer, but the pump will be at about 300ft. Ill want as much GPM/pressure as I can buy
 

wild01

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Ok your answer confuses me. 400feet to the aquifer but pump@300. There might be a better sq, but if you give me all the info well total depth static water level in well i' ll look up thepump curves tomorrow and get back to you. I'm working 7 12s right now so I gotta get to bed.
 

opticalcarrier

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1st off thanks very much for offering to help me out here - 2nd the well isn't in yet so I've not really been educated just yet so I'm not 100% on all the terms but what I think the well driller estimated on the wells around me that he'd need to drill down 400ft actually that number was 500ft to hit the aquifer but the pump itself didn't need to sit down that low, the pump install depth would be at a higher level he said 280ft (not 300ft like I previously said). I guess that higher level is the "static" pressure depth?

heres what he gave me:

DRILL 4 ½ INCH WELL @ 17.00 PER FT.

ESTIMATED DEPTH 500 FT.

$ 8500.00



INSTALL 3 HP - 25 GPM GOULDS SUBMERSIBLE PUMP,

PIPE, WIRE, TANK, CYCLE STOP VALVE

ESTIMATED DEPTH 280 FT.

$ 4000.00



TOTAL ESTIMATED PRICE

$ 12,500.00



PRICE FOR 3 HP – 25 GPM PUMP INSTALLATION USING

VARIABLE SPEED DRIVE

$ 6300.00
 

wild01

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Ok so static level is how high the water sits in the casing. Draw down is how far the level drops when the pump runs. Head is based on static level+ draw down plus desired pressure.
 

wild01

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So in selecting a pump actual well depth is not that important. all that really matters is how deep the water is in the well. I would advise to put the pump as deep as possible in the well, because in my experience casings tend to silt in below the pump. The quote you have is for a VERY powerful pump. 25gpm is a lot of water. What's your planned usage? If it's just a house/garden, you don't need anything that big.
 

Megunticook

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Hello, a little late to the party here but this thread seems to be just what I was looking for. I'm looking at the 3 SQF-3 as a replacement for my conventional Gould but not 100% sure this is the right choice. Would love to hear some informed opinions.

My drilled well is 580 feet. Not sure of the static level, what's the best way to measure that? I have an 8K inverter with a 430 amp-hour battery bank. Looking to reduce my well pump's load so it doesn't draw down the battery bank too quickly.

No special water demands at house so I was thinking 2gpm would be fine (well yield is only 2 anyway).

Based on how deep my well is I figured the 3 SQF-3 was the right choice. Is that correct?

Figured I could just continue using the existing dedicated 240VAC/15A circuit for the Grundfos. Sound logical?

Please educate me...I'm all ears. Thank you.
 

OzSolar

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Hello, a little late to the party here but this thread seems to be just what I was looking for. I'm looking at the 3 SQF-3 as a replacement for my conventional Gould but not 100% sure this is the right choice. Would love to hear some informed opinions.

My drilled well is 580 feet. Not sure of the static level, what's the best way to measure that? I have an 8K inverter with a 430 amp-hour battery bank. Looking to reduce my well pump's load so it doesn't draw down the battery bank too quickly.

No special water demands at house so I was thinking 2gpm would be fine (well yield is only 2 anyway).

Based on how deep my well is I figured the 3 SQF-3 was the right choice. Is that correct?

Figured I could just continue using the existing dedicated 240VAC/15A circuit for the Grundfos. Sound logical?

Please educate me...I'm all ears. Thank you.
Speaking from experience I can say that in "general terms" the energy (KWH's) to pump a given amount of water will pretty much be the same. I'm sure the SQ if more efficient but not enough to warrant swapping out until the Gould fails. The main advantage of the SQ pump would be how much easier it is for your inverter to start but it sounds like you already able to run your Gould pump, right? IMHO, your money would be better spend on adding solar panels and/or expanding your battery bank.
 
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