Hi Kelly: Are you sure about the XHHW listing. Doesn't that designate aluminum wire? You mentioned CU before.
I have seen some discolloration from copper wire against module frames, but not real corrosion. Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 ________________________________ From: "Kelly Keilwitz, Whidbey Sun & Wind" <ke...@whidbeysunwind.com> To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Sent: Fri, January 14, 2011 3:06:09 PM Subject: Re: [RE-wrenches] Incompatible Metals Scott, 300.3(2) allows grounding and bonding conductors to be outside of a raceway. See 250.134(B), exception 2. Kelly Keilwitz, P.E. Principal Whidbey Sun & Wind Renewable Energy Systems NABCEP Certified PV Installer WA Electrical Administrator 987 Wanamaker Rd. Coupeville, WA 98239 ke...@whidbeysunwind.com PH & FAX: 360.678.7131 On Jan 14, 2011, at 2:51 PM, Scott McCalmont wrote: 300.3(A) prohibits the use of XHHW outside of a recognized wiring method, which means you need a conduit or raceway. You can use USE-2 in an exposed outdoor location only because 690.31(B) allows it, but only for module interconnections. > >Scott > >On Jan 14, 2011, at 11:45 AM, Kelly Keilwitz, Whidbey Sun & Wind wrote: > > >Peter, >> Yes the #10 XHHW (2) we use is green-jacketed, and 90˚ rated. We get it through our local electrical supply house. > > Kelly Keilwitz, P.E. > Whidbey Sun & Wind > Renewable Energy Systems > ke...@whidbeysunwind.com > 360-678-7131 > > > > > On Jan 14, 2011, at 11:04 AM, Peter Parrish wrote: > > Great idea Kelly! I didn't know one could get green jacketed USE or XHHW. Do >> you have a source? Also, do you think that we might need wire rated "-2" for >> 90 deg C wet locations. I know that this is not a current carrying >> conductor, but roof tops are definitely 90 deg C wet environments. Your >> thoughts? >> >> - Peter >> >> >> Peter T. Parrish, Ph.D., President >> California Solar Engineering, Inc. >> 820 Cynthia Ave., Los Angeles, CA 90065 >> CA Lic. 854779, NABCEP Cert. 031806-26 >> peter.parr...@calsolareng.com >> Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 >> >> >> -----Original Message----- >> From: re-wrenches-boun...@lists.re-wrenches.org >> [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kelly >> Keilwitz, Whidbey Sun & Wind >> Sent: Friday, January 14, 2011 10:14 AM >> To: RE-wrenches >> Subject: Re: [RE-wrenches] Incompatible Metals >> >> Peter, >> I have never understood the common practice of using bare copper >> ground wire on and against aluminum frames and modules. It always has >> been a dissimilar metals issue. Just look anywhere copper has set >> against aluminum for awhile. >> We use #10 green jacketed Cu USE or XHHW conductor and strip away the >> jacket at each lug, using No-Ox on that section of bare wire at the >> lug. The wire can be tucked in to the module frames and with the PV >> conductors. >> >> Kelly Keilwitz, P.E. >> Whidbey Sun & Wind >> Renewable Energy Systems >> ke...@whidbeysunwind.com >> 360-678-7131 >> >> >> >> >> On Jan 14, 2011, at 7:36 AM, Peter Parrish wrote: >> >> One of my students who is currently responsible for standing for >>> inspection >>> at their company encountered a inspector who made an interesting >>> point about >>> incompatible metals (i.e. copper and anodized aluminum). >>> >>> The PV system in question used outdoor rated lay-in lugs to bond the >>> rails >>> to bare copper wire (so far so good). The ground wire was then zip- >>> tied to >>> the rail to carry it to the point where it entered a junction box >>> along with >>> the rest of the PV conductors. >>> >>> The inspector was concerned with the fact that the bare copper was in >>> contact with the aluminum rails and that this might cause galvanic >>> corrosion >>> and subsequent failure of the grounding. >>> >>> I have never encountered this issue before and I wonder if anyone >>> else has >>> and what was the outcome. >>> >>> As an aside: I do know that 10 AWG and 12 AWG solid bare copper >>> wire can be >>> purchased "pre-tinned" (maybe not tin per se, but coated). We did so >>> by >>> mistake. We used it up, but not before one inspector questioned its >>> use for >>> the purpose of grounding our system. We showed him the UL label on >>> the spool >>> and scraped off the coating to expose the copper core and that >>> satisfied >>> him. To this day I don't know if the use of this wire for grounding >>> was >>> among its intended purposes. >>> >>> - Peter >>> >>> Peter T. Parrish, Ph.D., President >>> California Solar Engineering, Inc. >>> 820 Cynthia Ave., Los Angeles, CA 90065 >>> CA Lic. 854779, NABCEP Cert. 031806-26 >>> peter.parr...@calsolareng.com >>> Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 >>> >>> >>> _______________________________________________ >>> 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 >> >> >> _______________________________________________ >> 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 > > _______________________________________________ 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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