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Grundfos SQFlex Solar Submersible Pump Info


The Grundfos SQFlex Submersible Well Pump has become a globally-recognized "gold standard" in the solar water pump market. European design standards and manufacturing and a 15 year production history make it a proven design which offers unsurpassed quality and longevity. Starting in Denmark in 1945, Grundfos rose to become one of the premier water pump manufacturers in the world, offering a full line of pumps for all areas of water use. With its 15 year production history, the SQFlex is now a proven solar water pump design for homesteaders, ranchers, preppers, and others interested in off grid living. For remote locations, it just makes more sense to harness the sun to power your submersible pump instead of hauling fuel to the pump.

The SQFlex solar powered water pump is designed to operate with energy provided by solar panels and variety of other sources such as wind turbines, generators, and batteries. When powered by solar panels, the pump runs when the sun shines. Water can be pumped to a non-pressurized tank which gravity feeds to a home or farm operation. The tank provides water storage when the sun is not shining. This is called "Array Direct" operation. No batteries are needed, and it is the most efficient way of using the pump.


This solar water pump can also be used with batteries in the system if you use a pressurized tank instead of a gravity feed tank. Use a reverse action pressure switch connected to the CU-200 pump controller. See the Grundfos SQFlex Battery Operated Water Pump Operation Guide

There's an SQFlex model for your off grid well:

  • The 60, 40, 25, and 16 SQF models are 4 inch diameter centrifugal rotor pumps for high-output wells less than 100 feet deep. The 11, 6, and 3 SQF models are 3 inch diameter helical rotor pumps and made for deep wells, maximum 820 feet.
  • The first number in the model designation shows the maximum gallons per minute, and the second number shows the number of stages. For instance, the 11 SQF-2 can pump a maximum of 11 gallons per minute and has two stages.
  • It's OK to use an SQFlex Solar Water Pump at depths which are shallower than the optimum depth shown in the chart. Sometimes the casing diameter will be too small for the 4" centrifugal pumps, or sometimes the well output is limited. For instance, you can use the "deep well" 3 SQF-3 in a 3" diameter shallow well, and you can use it in a well which only has a recovery rate of 3 gallons per minute.

To choose the best SQFlex submersible pump for your needs, see the Grundfos E-Z Pump and Solar Panel Selection Chart

To see all the SQFlex models, click here.

Why the versatile SQFlex is ideal for folks who live off the grid:

  • Easy installation: no external converter box is needed, just connect the pump to the power source.
  • ŸPump can run on two to seven 250 watt solar panels or your 1500 watt or larger generator.
  • ŸPump can be set up to fill either an open tank or a pressure tank.
  • Pump can run in a tank if needed.
  • The "Soft Start" feature reduces twisting on the output pipe, allowing the use of inexpensive NSF polyethylene pipe, which makes the installation much easier for homesteaders, ranchers, and preppers who want to do their own installation.
  • Pump can be positioned horizontally as well as vertically. For horizontal operation, make sure the low water shutoff sensor in the power cable is two feet above the pump.
  • ŸVarious models can provide from 1000 gallons per day to 40,000 gallons per day
  • Models are available which can provide from 6 to 820 feet of total lift.
  • ŸA dry run switch in the cable 2 feet above the pump will shut off the pump if the water level in the well drops too low.
  • An optional control box is available with a pump shutoff button and LED's on the front panel to indicate power consumed, pump status, etc.
  • You can also connect a float switch to the control box which will shut off the pump when your tank is full.
  • The SQFlex uses submersible pump cable with "two conductors and a ground". Many applications can use 10 gauge cable. See the Submersible Pump Cable Sizing Chart to select the correct size cable for your Grundfos submersible pump.

Grundfos SQFlex Submersible Pump Brochure

Grundfos SQFlex Solar Water Pump Brochure

SQFlex for Off Grid Living: Installation Stories

Grundfos SQ Flex Solar Water Pump Wiring Diagram

Solar Panels For Your SQFlex Submersible Pump

Grundfos SQFlex Detailed Product Guide with Pump Curves

Grundfos SQFlex Detailed Service Guide

Grundfos SQFlex Dimensions and Weights

Facts about Grundfos Pumps Corporation

gravatar-image-456-x-456.jpg  Thad's Tip: Click here to find out how to splice submersible pump cable.

  4" Centrifugal (shallow well) pumps on the left, 3" Helical (deep well) pumps on the right