Wrenches There used to be a product that changed battery strings from parallel to series to boost voltage, l know the patent holder, let me ask if it can work here that is if there are enough's batteries. Jerry
On Tue, Aug 21, 2018, 8:17 AM Gary Higbee <g...@windstreamsolar.com> wrote: > Hi Wrenches, > > I’m assisting a customer and well person in replacing a failed Lorentz > ETApump (after 15 years of intermittent use). We’re looking for a quality > DC-DC converter to power a not-yet- ordered Grundfos SQFlex 6 SQF-3 from a > 24 V Surrette battery bank (wish it was 48!). The pump draws a max of 8.4A > and the curves say we’ll need about 600 watts so I figure we’d want at > least 70 volts out. Ideal would be a higher DC output, say 200V (save a > couple hundred feet of larger copper, greater efficiency) and at least 3A > (see questions). > > The primary power source will be 240V AC but my customer wants a fallback > for battery operation. We plan to use the Grundfos IO 101 SQFlex switch > box, which will switch to DC if the AC fails. Also the CU 200 SQFlex > control unit, so we can accommodate the existing float switch up the hill, > etc. > > The Grundfos tech person I spoke with today said the DC system should be > able to supply 8.4A, regardless of the DC voltage.The pump curve says we > need 600W for maximum performance at the lift we’ve got. It seems to me > that if we’ve got 200V and need 600W we’d be drawing 3A. Yet if the > Grundfos factory line is there should be 8.4A available that’s 1680W. The > tech guy said he didn’t have specific information why we’d need 8.4A > regardless of pump input voltage. > > The Grundfos Product Guide says: > > *Max. ratings are as follows:* > *• Maximum power input (P1) of 1400 W* > *• maximum current of 8.4 A* > *• maximum speed of 3600 rpm *(think I read somewhere it’s 3000 rpm for > this helical rotor model) > > *The pump delivers its maximum performance when **one of the above > parameters is reached.* > > Two questions: > > 1) Do any of you have experience running the SQFlex on DC, and what to > make of the 8.4A at any input voltage factory recommendation? Maybe basic > amps/volts/power calculations aren’t applicable given the pump electronics? > > 2) Are you aware of any DC-DC converters that will get us from a nominal > 24V battery bank to 200V, or somewhere between 70 and 200V, with an > appropriate current limiting amp rating to get us at least 600W (depending > on thoughts regarding the above question)? > > > Thank you, > > Gary > > Gary Higbee > Windstream Solar > Oregon License 17LRT > Renewable Energy Consulting > g...@windstreamsolar.com > 541-954-3881 > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > >
_______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
