For what it's worth, I've run a single speed 1.5HP pool pump with a MS4448PAE in a mobile application on a 38.4kWh battery bank (sixteen Rolls S-530's). I have also run a 2.5HP Hayward EcoStar Variable Speed pool pump at full RPM, but that startup current is likely less than you well pump.
I'm going to guess your 3/4HP well pump will be a breeze to start with this inverter. Jason Szumlanski Fafco Solar On Wed, Jul 2, 2014 at 10:47 AM, Allan Sindelar <[email protected]> wrote: > Drake, > As a normal CYA, I'll always gently let a customer know that this (or any) > particular combination of inverter and load sometimes proves incompatible, > just in case the unexpected happens. (We once had a MS4448 that would not > reliably start and run a condensing boiler; a switch to a different boiler > resolved the issue.) > > Having said that note of caution, I wouldn't give it any concern. 3/4 HP > and 1 HP well pumps have never been an issue; I would expect 1.5 HP to be > easy to run. At 2 HP I'd be asking these questions here. > > You might check that it's a 3-wire, capacitor-start motor, but nowadays > nearly all are. Two-wire pumps (with no control box) can add 50% to the > surge. > > The Magnum has a fairly poor voltage regulation response. Sometimes the AC > voltage can drop to ~80 VAC momentarily. So you might also caution your > customer that the lights may flicker when the pump starts. In our home we > know whenever our Kenmore fridge turns on. > > Allan > > *Allan Sindelar* > [email protected] > NABCEP Certified PV Installation Professional > NABCEP Certified Technical Sales Professional > New Mexico EE98J Journeyman Electrician > Founder (Retired), Positive Energy, Inc. > *505 780-2738 <505%20780-2738> cell* > > > On 7/2/2014 8:17 AM, Drake wrote: > > Hello Wrenches, > > We are hoping to use a Magnum PAE 4448 to back up a household that > includes a 3/4 HP deep well pump. There is about 120 feet of vertical rise > and about 1000 feet of horizontal distance. > > I have been told that there is a correlation between the locked rotor > current of a pump and the predictable ability of a specified inverter to > power that pump. > > The plumber who installed the pump left no paperwork and retained no > records of what pump he put in the hole last year. He could only say it was > a 3/4 HP pump. We are therefore unable to obtain the manufacturer's > nameplate specifications. > > The Magnum PAE 4448 has a 1 mS surge of 70 A (at 240 V) and a 100 MS surge > of 40 A. According to the NEC Table 430.251(A), a 3/4 HP motor has a locked > rotor current of 41.4 amps at 230 V. > > This inverter can surge at 35.4 A for 5 seconds. The specified battery > bank will be 8 Full River L-16 AGMs. Can anyone say if: > > - Is there enough information to know if this setup will handle the > pump, and if so, will it? > - How can an inverter's ability to power a motor or pump be calculated > by knowing its locked rotor current? Which surge periods should be compared > to the locked rotor current? > - Does the surge current need to equal locked rotor. How long must the > inverter meet its required maximum surge? > - From experience with Magnums and pumps, does this seem like a good > combination? > > > Thank you, > > Drake > > Drake Chamberlin > > > > > > *Athens Electric LLC OH License 44810 CO License 3773 NABCEP Certified > Solar PV 740-448-7328 <740-448-7328> *http://athens-electric.com/ > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & > settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/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: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > >
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