Grundfos 11 SQF-2

Farmerboyz1721

Some questions for the Grundfos 11 SQF-2.

1. Do you have to have the CU-200 control unit? Can you wire straight to the pump and go?

2. If I wanted to control the flow of this pump, IE get 5 GPM instead of 11, can't I just cut the power back by installing half the solar panels? 

 

Anawa

I've been operating a 11 SQF for about 4 years. I have a CU-200 control unit and a 101 auxiliary portable generator unit. I do not think you can operate the SQF without the CU-200 as it monitors on-off as well as motor speed according to the available electrical energy.

The gpm is determined by the rotor rotation. I suppose you could "cut-back" on the PV and reduce the gpm, but the gpm will vary according to the amount of energy being received. The rated capacity of the SQF 11 is at the max output, but that does not mean you'll be getting 11 gpm all the time. 

Are you wanting max 5 gpm or a "steady" gpm?

Farmerboyz1721

Right now a 'steady' stream of 5 GPM will meet my demand. (Stored in a 1,700-gallon tank) As I develop my Homestead I forsee my demand going up. So, I want to the ability to max out my well capacity in the future. My logic was to buy the 11 SQF and operate it at a lower power input for now. Then, be able to increase the amount of panels on it when my demand increase. ( year or two down the road)

Anawa

Sounds like a plan and makes sense to me. You may want to "over panel" somewhat on your initial install to ensure you keep your tank adequately topped-off. Keeping in mind that the "pump-don't-pump" on those cloudy days. FWIW, my 11 SQF runs at max output on the 1.5 kW PV (215w X 7) and will completely fill my two 1,500 gal tanks in about 6 hours. You may get by with less overall wattage for your application, I opted for reliability since the pump can handle the load. My pump is about 450 LF from the controller/panel install and I was not sure how efficient the pump would run at that distance.

Something you may want to consider is to install a flow meter at the well head to monitor both the flow rate and the overall output. Hopefully, this is something that will fit within your budget. 

I would suggest, however, that you verify your incremental install plan with a Grundfos rep just to be on the safe side.

Good Luck!

Farmerboyz1721

Thank you for the feedback. I just got off the phone with Grundfos and they confirmed my plan. I was thinking of a flow meter as well, so I have added that to my plan. Luckily my panels will be fairly close to my well head. 

What's your static water level and total feet of head? 

Anawa

It's been awhile since I've looked at the data, but I think the static water level was about 20', the pump is set down at 185', and the tanks top out about another 60-70'. My well recharge is approximately 18 gpm with the primary water vein found at 145'. I think.