Hi Mark, I dont' have the SMA white paper. However I wonder if the "optimal" is for array to inverter sizing ( ie rare clipping ) but not necessarily for inverter reliability?
jay peltz power On Aug 19, 2011, at 10:56 AM, Mark Frye wrote: > Ray, > > Here are the nameplate module rating vs nameplate inverter rating: > > - 24 x 175 W = 4,200 W : IG4000 = 4,000 W : 105 % > - 18 x 175 W = 3,150 W : IG3000 = 2,700 W : 117 % > - 8 x 175 W = 1,400 W : SB1100 = 1,100 W : 127 % (sub-optimal orientation > limits peak power levels) > > I think it is fair to say that amps=heat=component aging. The question is to > what extent can the installer rely on the representations made by > manufactures with respect to their ratings and product life? > > For instance, the 24 module system above lands well within the Fronius > specifications for max DC power and is "Good" based on their online > configuration tool, and also well in line the the SMA white paper of many > years ago suggesting a 120% mod/inv ratio as optimal. > > And yet, the first unit failed in 4 years and the refurb failed in 2 year. > > Mark Frye > Berkeley Solar Electric Systems > 303 Redbud Way > Nevada City, CA 95959 > (530) 401-8024 > www.berkeleysolar.com > > > From: re-wrenches-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ray Walters > Sent: Friday, August 19, 2011 10:26 AM > To: RE-wrenches > Subject: Re: [RE-wrenches] Out of Warranty Inverter Replacements > > Hi Mark; > > In cases like that, I let the customer decide. My job is to present them with > two or three streamlined options and let them decide. > It seems it comes down to cost vs continued warranty (and possible > expandability?). Financial decisions ultimately need to be made by the people > paying the bill. > From a technical perspective, I don't ever present an option that I wouldn't > be comfortable installing, and in the end everyone's happy. (hopefully) > > Just curious; what are the array sizes relative to the inverter rating? I > always wondered if inverters that were run at or over their rating didn't > last as long as inverters that were run well below their rating. (just my > stupid assumption that: more amps = more heat = less reliability) > > Ray > > > On 8/19/2011 11:03 AM, Mark Frye wrote: >> >> Folks, >> >> Yesterday I took a trip through my service area and initated 3 inverter >> replacement actions: >> >> - A 6 year old Sunnyboy 1100W, 5 year warranty expired, $360 for a >> refurbished unit w/ 1 year warranty, new replacement not available >> >> - A 2 year old Fronius IG4000 refurbished, sent as warranty replacement for >> unit failed at 4 years under 5 year warranty, now out of warranty, est. $ >> 600 to refurbish with 1 year warranty >> >> - A 4 year old Fronius IG3000, under 10 year warranty, warranty replacement >> and service fee provided by Fronius >> >> I have to decide, what is best for my out of warranty customers: >> >> - Buy the refurbished units w/ 1 year warranty >> - Buy new replacement units with 10 or 20 year warrranties >> - Buy entirely new equipment such as Enphase or SolarEdge >> >> What are other folks experiencing as we move well past the 5 year warranty >> horizon for many of our earlier customers? >> >> Mark Frye >> Berkeley Solar Electric Systems >> 303 Redbud Way >> Nevada City, CA 95959 >> (530) 401-8024 >> www.berkeleysolar.com >> >> >> >> _______________________________________________ >> List sponsored by Home Power magazine >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Options & 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 >> > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & 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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