Howie, I've looked at a few different MC cable manufacturer data sheets and I can't find a distinction between AC or DC. In general I wouldn't expect there to be a difference since AC RMS voltage and current ratings are sort of a 'DC equivalent'. But the only way to be sure is contact a cable manufacturer and ask a specialist. There could be something buried in the listing. And we all know it is expensive to get a hold of UL standards to look the damn thing up ourselves.
Example MC cable data sheet: http://www.afcweb.com/pdf_2011/p12_mc_s_lt.pdf I am guessing that John Wiles was referring to 690.31(E) which has to do with running inside a building with DC conductors before hitting a DC disconnect. This section was changed in 2011 NEC to include MC cables specifically. Maybe from this it got lost in translation back to you? Good luck, Jason M. Szrom, PE Engineering Supervisor Solar Energy Systems, LLC 718-389-1545 x13 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Howie Michaelson Sent: Monday, October 21, 2013 2:15 PM To: RE-wrenches Subject: [RE-wrenches] MC Cable for DC runs Hi All, Just had a conversation with an electrician friend who took a John Wiles course for inspectors a couple of weeks ago, and he thought (but wasn't sure) that John said in order for it to be code to use MC cable for PV homeruns inside the building envelope, the cable needed to be rated for DC. This was new information to me, particularly since I've never heard of MC cable being rated specifically for DC. Is this accurate information, and does anyone know what the wire spec would be for this? Thanks, Howie -- Howie Michaelson NABCEP Certified Solar PV Installer(tm) Catamount Solar, LLC Renewable Energy Systems Sales and Service VT Solar Electric & Hot Water Incentive Partner http://www.CatamountSolar.com 802-272-0004 _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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 _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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
