Qustion for someone experienced with Grundfos SQ-FLEX [RE-wrenches]

[Doug Pratt]

Steve,

I agree with Christopher that a small sealed battery pack would
eliminate many potential system gremlins. A little ballast to even out
any voltage variations, fluctuations, or surges is going to make the
system more reliable in the long run. I think you could make the battery
quite small, say 30 to 50AH @ 48 volt, and then use a diversion
controller to switch the pump off if voltage drops too low due to some
hydro or water supply problem. Just replace the battery pack at 3-4 year
intervals.
  I agree with your pump choice. You can't beat the Grundfos SQ Flex for
efficiency, reliability, and life expectancy. I've sold a lot of them
the past couple years with only pleased reports back. I worry about
lightning, with all those electronics down the hole, but the Flex is a
spinoff of the SQ line that Grundfos has been installing for years, so
I've got some faith in their experience.
Cheers,
Doug Pratt

-----Original Message-----
From: Christopher Freitas --- OutBack Power
[mailto:cfreitas at outbackpower.com] 
Sent: Friday, February 27, 2004 7:17 PM
To: RE-wrenches at topica.com
Subject: RE: Qustion for someone experienced with Grundfos SQ-FLEX
[RE-wrenches]

Steve -

I would suggest looking at a more standard configuration of a system
with a small sealed battery bank to buffer the operation.  Yes - this
will require some annual maintenance - but so does a hydro power system.
The idea that "no maintenance required" systems are the solution is
false in my opinion.  Even a system with batteries will still require a
lot less maintenance than the generator and will be cheaper over time.  

I would look at using a 24 or 48 vdc submersible pump perhaps - or
possibly even a standard 1/2 HP 120 vac pump powered by an inverter.
Sure seems like you could get more than 300 watts from the harris unit
as well with your  fall and flow - then the pumping efficiency is not as
critical.  I would think a fairly small battery (four sealed AGM 100 AH
12V) should be more than able to start and run the pump as long as the
hydro is producing enough power.  

Christopher Freitas
OutBack Power Systems
cfreitas at outbackpower.com
19009 62nd Ave NE 
Arlington WA 98223 USA 
Tel 360 435 6030
Fax 360 435 6019
www.outbackpower.com 


>> -----Original Message-----
>> From: Steve Willey, Backwoods Solar 
>> [mailto:steve at backwoodssolar.com] 
>> Sent: Friday, February 27, 2004 6:38 PM
>> To: RE-wrenches at topica.com
>> Subject: Qustion for someone experienced with Grundfos 
>> SQ-FLEX [RE-wrenches]
>> 
>> 
>> I have an unusual application requested for a nearby Forest 
>> Service campground project. They have a fine hydro site for 
>> a Harris unit, probably yielding 300 - 350 watts (170 foot 
>> head on full 4 inch pipe with more than enough flow).  The 
>> unusual part is the application:  a submersible pump to pump 
>> minimum 1000 gallons per day up 270 feet head through a 1 
>> inch pipe of great length from a 4 or 5 gpm drinking water 
>> well source. The hydro turbine and well are located 
>> together, and about 25 miles from commercial power. This 
>> replaces an engine generator manually started each day. The 
>> hydro driven pump is intended to operate full time, no start 
>> or stop except in the event of dry-run protection.
>> 
>> My first thought was ETA or Grundfos Flex pump. The SQ-Flex 
>> pump 3SQF-2 seems well able to deliver over 150 gallons per 
>> hour at a 266 ft lift using 270 watts.  All good numbers 
>> showing more than enough water at the lift head, volume 
>> still within the well source's capability, and just under 
>> the probable hydro output with one nozzle.
>> 
>> The big unknown is whether it would be possible to power the 
>> pump direct, no batteries, from a Harris turbine DC output. 
>> I have not used the Flex pump before and am not familiar 
>> with SQ Flex power requirements regarding surge (none), 
>> noise tolerance, and inductive nature of rectified 
>> alternator output power. I do happen to have in stock a 300 
>> and a 600 watt Hydromax adjustable LCB control that could be 
>> used to interface and control voltage loading of the 
>> alternator, but the pump is claimed to have built in MPPT 
>> for solar. Grundfos also offers an IO-102 control for H80 
>> windmill connection, that might just be the solution here. I 
>> wonder how it would respond to the power
>> curve and noise of rectified DC from 3 phase alternator 
>> output.   We hope to
>> avoid batteries here, but I know addition of batteries would 
>> certainly remove the questions from this installation.... 
>> until the batteries go bad and no one has noticed. And it 
>> would take a lot of batteries for the 110 volts to meet the 
>> charted performance specs. Does anyone have experience 
>> coupling a Harris type alternator DC output directly to a 
>> Grundfos Flex pump in the power and performance ranges listed above?
>> 
>> Steve Willey,
>> Backwoods Solar Electric Systems
>> steve at backwoodssolar.com
>> 

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