I agree with needing to read the center-tap paper. However, we have found that it's sometimes just as easy and cost effective to use shorter strings and combine in AC load centers for a run to the interconnection point. It depends on the layout and how many splices and j-boxes you would need.
Come to think of it... that really applies more to 240Vac service. 3-pole breakers and panels are more pricey. Jason Szumlanski Fafco Solar On Thu, Oct 3, 2013 at 3:53 PM, Holt Kelly <hol...@sbcglobal.net> wrote: > Be sure to read Enphase’s tech sheet on center tap of branch circuits. ** > ** > > ** ** > > Holt E. Kelly**** > > Holtek Fireplace & Solar Products**** > > 500 Jewell Dr.**** > > Waco, TX 76712**** > > www.holteksolar.com**** > > 254-751-9111**** > > ** ** > > *From:* re-wrenches-boun...@lists.re-wrenches.org [mailto: > re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Nathan Stumpff > *Sent:* Thursday, October 03, 2013 2:28 PM > *To:* RE-wrenches > *Subject:* Re: [RE-wrenches] Enphase commercial**** > > ** ** > > Hi Eric,**** > > ** ** > > It is 25 inverters on a 20A circuit, but only on 208 three phase. Each > micro connects to the cable in an alternating way (L1/L2, then L2/L3, then > L3/L1, etc.) so with 25 micros there are either 8 or 9 micros on each > combination.**** > > ** ** > > 9 x 1.0 A x 1.732 (square root of 3) x 1.25 = 19.48 A = 20 A breaker**** > > ** ** > > Cheers,**** > > -Nathan**** > > ** ** > > --**** > > Nathan J. Stumpff**** > > NABCEP Certified PV Installation Professional #091209-175**** > > NABCEP Certified Solar Heating Installer #032412-14**** > > Project Manager | Arctic Sun, LLC**** > > nat...@arcticsun-llc.com | (907) 457-1297**** > > www.reina-llc.com | www.arcticsun-llc.com**** > > [image: Description: ZA102637861] <http://www.facebook.com/ArcticSunLLC>** > ** > > ** ** > > *From:* re-wrenches-boun...@lists.re-wrenches.org [ > mailto:re-wrenches-boun...@lists.re-wrenches.org<re-wrenches-boun...@lists.re-wrenches.org>] > *On Behalf Of *SunHarvest > *Sent:* Thursday, October 03, 2013 10:52 AM > *To:* RE-wrenches > *Subject:* [RE-wrenches] Enphase commercial**** > > ** ** > > Hey Wrenches & Nick Soleil (with whom I worked at APS for a time I > believe...),**** > > **** > > I'm not familiar with Enphase commercial applications and am currently > working through a commercial design. Enphase, on their M215 datasheets > claim up to 25 micros per branch, at 1.0A each, with each branch > terminating at a 20A breaker. By my calculations, 25 micros at 1.0A each > (25A*1.25=31.25A) need to terminate at a 40A breaker. Anyone know what I'm > missing or know how the 20A breaker design gets past the AHJ?**** > > **** > > Eric Stikes > SunHarvest**** > > (530) 798-3738**** > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > >
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