Howie, I think your electrician friend either misheard John or John was wrong. I believe the truth is that AC cable (aluminum clad) would have to be listed for dc. The NEC is specific about the grounding capabilities of the MC. I am unaware of any specific dc or ac requirements that MC has. There is a possibility that MC may be sold with an aluminum sheath. I'm not sure why aluminum sheathing would have anything to do with how it works, but since AC cable has that concern, this may be what John is referring to.
Overall--it is bad form to say that anything is not allowed without specific references regardless of the source. I have made a few false statements in the past and I greatly regret those mistakes. I now try to back up my statements with as much information as possible so that the source of the information is clear. Sometimes (often) I have opinions and I try to make it clear when I am stating my opinions. John has been known to make mistakes. Unfortunately some of his recent articles in IAEI journal have several mistakes which is really bad since AHJs read his articles carefully. Hopefully we can get new articles in IAEI journal that set the record straight. Bill. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Howie Michaelson Sent: Monday, October 21, 2013 11:15 AM 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 InstallerT 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
