Mick, THWN-2 is 90°C rated per Table 310.16. This is key for conductors in conduit on a roof. On a roof in full sun ambient temperatures are such that a 75°C rated conductor will have a severely diminished allowable ampacity, if any allowable ampacity.
Jollily, David On 7/23/10 11:52 AM, "Mick Abraham" <m...@abrahamsolar.com> wrote: > I'm sorry to broadcast my ignorance, but: > > Could someone explain to me the significance of the -2 marking? Reply off-list > if you wish to save bandwidth...but other List members may also be > wondering... > > Thanks, > > Mick Abraham, Proprietor > www.abrahamsolar.com <http://www.abrahamsolar.com> > > Voice: 970-731-4675 > > > On Fri, Jul 23, 2010 at 10:48 AM, Nick Soleil <nicksoleilso...@yahoo.com> > wrote: >> I have specified THWN-2 for years, but occasionally will not be able to >> source it! >> >> Sent from my iPhone >> >> On Jul 23, 2010, at 11:37 AM, "Peter Parrish" <peter.parr...@calsolareng.com> >> wrote: >> >>> We went through a similar problem with some beach communities here in SoCal. >>> Because of the high humidity (all winter and summer mornings) they wanted >>> THWN-2 for all conduit runs (as well as PVC instead of EMT). At first we >>> were charged a premium for THWN-2 compared to THHN. But then we found a >>> source at All Phase Electrical Supply Burbank CA (a part of CED) for THWN-2 >>> #10 stranded @ $162.40/k-ft. Brand is En(m?)core Wire. THWN-2 listing is >>> printed on the insulation. >>> >>> - 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 >>> <mailto:peter.parr...@calsolareng.com> peter.parr...@calsolareng.com >>> Ph 323-258-8883, Mobile 323-839-6108, Fax >>> 323-258-8885 >>> >>> >>> >>> >>> _______________________________________________ >>> >>> List sponsored by Home Power magazine >>> >>> List Address: <mailto:RE-wrenches@lists.re-wrenches.org> >>> 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> >>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >>> >>> List rules & etiquette: >>> www.re-wrenches.org/etiquette.htm <http://www.re-wrenches.org/etiquette.htm> >>> >>> Check out participant bios: >>> www.members.re-wrenches.org <http://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
