Grundfos SQFlex 40 SQF-5 Submersible Pump

The Grundfos SQFlex is an industry-leading submersible pump for water lifts of up to 800′. SQFlex pumps can be directly powered by solar or wind or can be run on an inverter, generator, battery, utility grid, or any combination of these sources. Virtually any source of power, 30 to 300 VDC and 90 to 240 VAC, can be used to run this pump.

They can operate on a series string of PV modules with a total peak power voltage of at least 30 VDC, but its efficiency will be highest at voltages over 100 VDC (10% less efficient at 60 VDC, and 20% less efficient at 35 VDC). Its motor is designed to draw a maximum of 8.4A, which means that many types of PV modules can be used with this pump efficiently, including common 60 cell modules.

SQFlex models 3SQF through 11SQF will fit into a 3″ or larger well and models 16SQF-10 through 60SQF-3 will fit into a 4″ or larger well casing.
The 11 different pump models available can deliver from 77 gpm at 6′ of head to 3.5 gpm at 800′ with a 1.6 kW or smaller solar array. Use the helical rotor pumps, 3SQF, 6SQF and 11SQF, for high head applications and centrifugal pumps, 16SQF, 25SQF, 40SQF and 60SQF, for low head applications for best efficiency. The SQFlex has built-in protection from dry-running, overloading, and overheating.

See Grundfos SQFlex Submersible Pump Selection Chart

Grundfos SQFlex Optional Controls

SQFlex controls can be combined if you need more features than one control can provide. The CU200 interface box communicates with the pump and monitors operating conditions. Built-in diagnostics indicate faults and dry-running, as well as display operating status, power consumption, and water level switch input. The Water Level Switch interfaces with the CU200 control to turn off the pump when the tank is full. Since the CU200 control circuit uses only 15 mA, the water level switch can be located in a tank as far away as 1,640′ from the pump, using a minimum #18 AWG 2-conductor wire.

The IO50 control box includes cable terminations and a simple manual on/off switch that interfaces between a solar array and the pump to allow you to turn off the high voltage array when servicing the pump or plumbing.

The IO101 AC interface box is for using AC backup on a solar pump. An automatic transfer switch disconnects the solar array when AC power from a generator (120 VAC only), utility connection, or inverter is present. When AC power stops, it automatically reconnects the array to let the sun continue pumping. The SQFlex pumps will not function with a GFCI in the supply circuit and should not be used where a GFCI is required.