Grundfos SQFlex Pre-designed Solar Water Pumping Kit using 25 sqf-7 pump 40-18gp


Last updated on July 1, 2024 5:52 pm


Grundfos SQFlex Pre-designed Solar Water Pumping Kit using 25 sqf-7 pump 40-18gpm, 35 to 185 5 panel SunRac Mount

This Grundfos Predesigned Solar water pumping kit includes 5 x 330w Solar Module wired in series (positive to negative) for high voltage input to the pump and or controllers. From the solar panel array we would go to the MNPV3 combiner box using the included MC4 extension cable. The Grundfos solar water pumping kit include a top of pole solar panel mount is made specifically for these solar panels. The customer is responsible for purchasing the schedule 40 steel pipe the mount requires. This pipe is normally available locally at fencing suppliers or steel suppliers. The included grounding lugs for the solar panels and mount will connect to a customer supplied 6awg bare copper stranded wire to the combiner box and then to a grounding electrode driven near the array into the ground.

In the combiner box we would have a 20a DC breaker rated for 150vdc for up to 3 panels or a 20a 300vdc breaker for up to 6 panels in series for arrays of 8 panels we would suggest two 300vdc breakers in the combiner box. The combiner box would also house a lightning arrestor.

A lightning arrestor is required with the Grundfos extended warranty included with the Grundfos Solar Water pumping kits. The Extended warranty extends the warranty period to a total of 5 years. From the combiner box the positive and negative outputs would go to the Grundfos CU200 controller and then directly  to the Grundfos SQflex 25 SQF 7 pump itself. The Grundfos SQflex pump has a total of three wires. The yellow and green wire is the ground with the other two wires being non polarity sensitive. The wire is connected to the pump via the included underwater splice kit

The Grundfos CU200 controller provides a combined status and control unit for the SQFlex pump kit system. The CU200 includes a digital display that provides information on the power the pump is using and will display fault codes for troubleshooting the system if needed. Additionally, the CU 200 enables connection of a level switch placed in a water reservoir or tank. A reverse action pressure switch is used in situations were a float valve is required in most cases this is due to the 2000 feet max distance between the cu200 and the float switch. We have found also that keeping the cu200 and pump within 650 feet is preferred.

The Optional Grundfos IO101 controller ( not included) provides easy transfer between the solar array and an ac source such as a generator or grid power. The US version of the IO101 can only take max of 120vac even though Grundfos SQflex pump is good up to 240vac.

The 10/2 with Ground submersible pump cable is not included since the placement of the pump in most cases varies, in calculating the flow rates and vertical lift the calculations are based on the static water level rather than the pumps depth in the well. The Grundfos SQFLex pumps have a maximum submergence level of 500 feet from static water level.

Depending on the distance from your solar panels to the well head you may want to run underground feeder cable (UF wire) to save money and splice in the submersible pump cable at the well head. The connection to the pump would be done with an underwater splice kit.

There are also additional items to complete the system that are generally available locally and include:

  • 6 awg copper stranded wire for grounding solar panels to combiner and then to electrode.
  • 8’ Grounding electrode and wire clamp
  • Concrete and rebar for the mount hole (we can provide dimensional drawing for hole)
  • sch 40 steel pipe for mount
  • Screws to mount combiner box and controller to the pole/mount.
  • Zip ties to attach MC4 extension cables to mount frame.
  • Electrical Conduit to go from solar panels to combiner box and then to below ground
  • ??’ 10/2 w/ ground UF wire from combiner box to well head, you could use same sub pump cable although UF wire is cheaper.
  • ??” diameter drop pipe to pump,  diameter dependent on pump model.
  • 3/8 “ Polypropylene Safety rope (not required if using galv steel pipe)



330w Solar Module x 5


MC4 Solarline 2 PV Array Output Cable 50′ #10 AWG


Midnite Solar MNPV3 Combiner Box for 3 150VDC or 600VDC breakers


LA302DC Delta Lightning Arrestor to 0-300VDC
– Mounting Bracket Required: No


DIN Rail 300VDC Breaker
– Amps: 20A




Splice Kit for Submersible Solar Water Pump Wire


Grundfos SQFlex 25 SQF-7 Solar Submersible Pump


Grundfos SQFlex CU200 Interface Box Pump Controller
– Level Switch Required: No


Grundfos SQFlex Water Level Switch (use with CU200 only)


Grundfos SQF Flex Solar Water Pump 5-year extended warranty



Sun Rac Mount for 5 solar Panels ( 2 poles required)