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Hook up I have a 6 sqf-3 well pump and a grundfos sqf-cu200 controller Have been running well with generator, and finally got my solar panels up. Problem: Hooked up 4 12 volt 120 watt each panels in a 48 volt configuration, pump rums at about .42kw. Hooked up 4 more panels, 48 volt configuration,and tied the 2 together in parallel , and the pump tries to start, and quits. Pump will run with either bank of panels, but not both of them at same time. I then hooked all 8 panels in a 96 volt configuration, pump runs great. Checked everything multiple times, cannot figure why it won't run at 48 v0lts, 2 banks of panels tied together.

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Posted on Jan 02, 2017

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SOURCE: Grundfos MQ pump starts every 15 seconds

Pressure is bleeding back through the pump or system to the tank or well or where ever the water is coming from. Should be some sort of one way valve to keep water from going back to the source, mounted somewhere so that once pressure is pumped up, it will hold that pressure in the part of the system that has the pressure switch that controls the pump.

That or you have a leak where you can't see it. (Actually you do, it is just internal and not leaking outside the pipes!)

Posted on Nov 05, 2012

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Check the thermostat.

Posted on Aug 02, 2014

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