Grundfos 6-SQF-2 controller needed??

[kmmtnman]

Relay

Make sure the relay can handle the DC amps and volts, without burning up or welding the contacts. AC devices used in DC circuits don't last long.

This is what I bought. Looks like it should be up to the task. Bought a spare too. Hope it works..

http://www.alliedelec.com/search/pro...x?SKU=70174878

[Mike90250]

Add the socket, retention clip, and a "inductive kickback" diode, and you should be OK.

A relay coil without a anti-kickback diode, is also called an automotive ignition coil

http://en.wikipedia.org/wiki/Snubber#Diode_snubbers

http://www.allaboutcircuits.com/vol_3/chpt_3/9.html

[sfblackrobe]

I'm late in replying to this thread. But this may be helpful to some.

We've got two wells with Grundfos 6SQF-2 and -3. We built our own controller to use solar panel DC (direct, no batteries, no inverter) when the sun is out and producing enough power to drive the pumps. It switches to AC grid when there's no sun and we need water. We've also got a timer as part of the system. We're using the Irritrol pccontrol for irrigation and it has a "landscape lighting" feature, so to go to solar power we need two things: 1) it's got to be in the time range we've set; 2) there's got to be enough voltage on a single panel (now set for 38 VDC) to insure enough power on the panel arrays (3 and 4 panels respectively).

It's working fine. We can pump 5,000 gal/day when needed.

[Texas Wellman]

The pump/motor doesn't care what the input power is as long as it's 30-300VDC or 90-230 VAC. You don't need the interface box and you can run it just like a regular well pump or even direct solar (I don't recommend wiring direct).

Hello,

I'm new to blogging, but have been developing my 5 acres of paradise in the mountains for several years.
When we bought the property it had a 240v well pump but the down pipe was shot. We replaced the pump with a 6 SQF-2 and down pipe w schedule 120pvc and stainless connectors. We have been running the well pump off of generators with no controller, but I now want to run it direct off of a 790w 50vdc array. I want to put a timer on it so it comes on a couple hours a day to top off the 2.6k gal tank uphill and the overflow waters the garden. Has anyone wired an SQF pump dc without the Grundfos controller? I've been doing with ac without any problems. The controller is 300 bucks and really doesn't do much for you except allow for a float switch, which I don't want anyway. BTW there is no power for 20 miles

Thanks,

[bcroe]

Mpp

The pump/motor doesn't care what the input power is as long as it's 30-300VDC or 90-230 VAC. You don't need the interface box and you can run it just like a regular well pump or even direct solar (I don't recommend wiring direct).

If that pump does incorporate an MPP function, the voltage from the solar array
will be fairly constant while it runs over the day, at the Vmp of the panels. This
doesn't change a lot over varying sun, if there is no partial shading. If the voltage
varies widely, an MPP controller would likely increase efficiency & power. Bruce Roe

[Texas Wellman]

MPPT is built into the grundfos.

If that pump does incorporate an MPP function, the voltage from the solar array
will be fairly constant while it runs over the day, at the Vmp of the panels. This
doesn't change a lot over varying sun, if there is no partial shading. If the voltage
varies widely, an MPP controller would likely increase efficiency & power. Bruce Roe