Grundfos sqf questions

bbbuddy · May 2021

I've decided to switch my Goulds 1hp pump to a Grundfos sqf. There's nothing wrong with the Goulds but it's now 17 years old. I figured to keep it as a backup to the Grundfos if it ever needs to be pulled for fixing.

As an aside, we found a guy near up selling 275 watt 4 year old panels from a solar farm in New Mexico, we bought 12 for $65 each, to replace our original eight 100 watt 75v panels and another six 200 watt 26.2v panels.

I can configure our old panels for 150volts/1800watts to the pump, but the amps would be 11.79Imp. The pump (25sqf-7) max amps is 9amps.
This would be 6 panels 26.2v = 157v at 7.68Imp paralleled with 6 panels series and paralleled 75v = 150v at 3.99Imp.
---> This over paneling would not hurt the pump? In fact would give more water on a cloudy day than otherwise? Just checking to be sure...

Also, I would add a diverter valve so I could pump into my 3,000 gallon water tank, using the Grundfos float switch to avoid overfilling, but also divert to pump directly to irrigation. This would mean adding an off switch for the float switch between the control box and the float so the pump would work when the tank is full. Is there any problem with that? Or is there a better way to do this?

Getting older now, don't trust my brain to get it right, thanks!

wellbuilt · May 2021

How much water do you need ?
If your pump was set at 130’ you could get 24gallons a min with 1400 watts in full sun .
I read in the manual some where that you can use 120vs with out cutting production so if you get 2 hours of full sun
you could fill your tank .

That pump can be run on grid so if you hooked it to a 200 amp service in a home the pump would use the power it needs with no damage .

You are better off pumping water at the rate you need so you are not drawing water down and bringing dirt silt into your well . Bigger is not always better .
I’m no expert but I’m getting ready to set a SQF 6-3 in a deep well so a lot of the specifications are fresh in my mind .

wellbuilt · May 2021

only problem I see is if you tank is full you won’t get any water for irrigation .

Maybe just a on off switch and a timer to run your irrigation once or twice a day .
Your tank could be filled at the same time just limit the water going to the tank.

bbbuddy · May 2021

My well could provide 1200gpm with no drawdown if I had a big enough pump there so no worries on that front.

I want to get at least 20gpm at 20 psi for 6 hours per day which the pump curve shows I can in full sun.
My questions are regarding over paneling, and interrupting the signal from the tank float switch so the pump would run even with the tank full.
Looks like over paneling is not a problem.
I don't want the water pump connected to my house panels/inverter except for 240 volt power from my house system in an emergency, like: a week of clouds/empty tank. We already have that power to the Goulds control box, we'd just switch it to the Grundfos controller.

In the winter the float switch would be always on, diverter valve pointed to tank, no irrigation.

wellbuilt · May 2021

I think you are ok over paneling .
I don’t think the cu200 controler has a way to over ride the float so you would need to open the Circuit in the pump wire .
Maybe you can unplug the float wire from the control box ?

bbbuddy · May 2021

wellbuilt said:

I think you are ok over paneling .
I don’t think the cu200 controler has a way to over ride the float so you would need to open the Circuit in the pump wire .
Maybe you can unplug the float wire from the control box ?

Rather than do that I was thinking put a switch on one of the float switch wires...unless someone has a better way.

Grundfos sqf questions

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