>From my experience with reflective roofs galvanized quickly ages becoming less reflective! White is best aluminum paint next. Ken Schaal CommonWealth Solar
On Thu, Nov 19, 2020, 9:17 AM frenergy <frene...@psln.com> wrote: > This is a very timely discussion for us also as we have many > Midnight MNPV6 discos in the sun. Though we're careful about tightening > wire landings, using contact cleaner for the fuses and fuse holders, some > installs seem to get hotter than others. We just started making a very > simple sheet metal heat shield of sorts spaced away from the face of the > disco for ventilation which keeps direct sun off the "face" of the disco. > We don't paint this shield to give the galvanized surface a chance to > reflect the IR. > > Its a retro which we've covered the cost for to prevent > callbacks for blown (cooked?) fuses. I haven't done any before and after > temp checks but I know from a long history of this kind of work that temps > inside that disco will be substantially lower. They haven't been out in the > field long enough to get any data. > > Bill > > Feather River Solar Electric > Bill Battagin, Owner > 4291 Nelson St. > Taylorsville, CA 95983 > 530.284.7849 > CA Lic 874049www.frenergy.net > > On 11/18/2020 5:13 PM, Ray wrote: > > What is the brand and model of the disconnect? Temp ratings of the > terminals? I've definitely had fuse holders not make good contact with the > fuses and burn the fuses at one end, instead of in the middle. Have you > looked at it with a Thermal imaging camera when its operating to see if its > hot on one end of the fuse? > > Second, depending on the temperature it would be hitting inside the > enclosure in the sun, you could be exceeding the rating of the #6 > conductor. Assuming terminals rated at 75C, then from 310.16, a #6 is > rated 65 A, but derate for temperature of 114F inside the enclosure gets > you to .82 x 65 = 53.3, which is a bit less than the 54.45 that Dave just > calculated for continuous duty. > > What color is the disconnect painted? any chance of painting it white? > > Ray Walters > Remote Solar > 303 505-8760 > > On 11/18/20 4:16 PM, Dave Tedeyan wrote: > > Jason, > Bright sunny days, disconnect on the west side of house, maybe in the sun? > 43.56A * 1.25 for continuous duty = 54.45A. If these disconnects are also > baking in the sun, maybe the extra ambient heat is enough to push it over > the edge? Just a thought. > Cheers, > Dave > > *Dave Tedeyan, PE* > Senior Engineer | Taitem Engineering, PC > > 110 South Albany Street | Ithaca, NY 14850 > o. *607.277.1118 x121* f. 607.277.2119 > www.taitem.com > > > > ------------------------------ > [image: Avast logo] <https://www.avast.com/antivirus> > > This email has been checked for viruses by Avast antivirus software. > www.avast.com <https://www.avast.com/antivirus> > > <#m_8636614259925677905_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > _______________________________________________ > 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 > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > >
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