Mike Dolt Enterprises
Mike Dolt Enterprises
User: rochaconstruct, Location: Chapel Hill, NC
Asked on: Friday, April 22, 2011 at 1:08 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:32 am EDT
Question: I was called to inspect an office complex made up of 17 ea 12 x 60 mobiles, factory wired with NM cable, as I hadn't looked at a mobile in a while I re-read Articles 550 and 334. There are hundreds of these at this facility, to my surprise I discovered that in none dwelling mobiles with suspended ceilings NM cable is not allowed.Is there an exception to this somewhere, nearly every trailer on site is wired with NM cable?
Article 550.13 requires that electrical installations in mobile homes and mobile home parks be made in accordance with the provisions of Article 550 and Article 334.
Article 334.10(1) prohibits the use of NM cable in concealed locations in unfinished attics and roof spaces of dwelling units.
Article 334.10(2) prohibits the use of NM cable in concealed locations behind bathroom walls in dwelling units.
Article 334.10(3) prohibits the use of NM cable in concealed locations where subject to contact with thermal insulation.
Article 550.13(A) Exception No. 1: Concealed NM cable is permitted in unfinished attics and roof space of a non-dwelling mobile home.
Article 550.13(A) Exception No. 2: Concealed NM cable is permitted behind bathroom walls of a non-dwelling mobile home if there is a vapor retarder on the warm side of the wall.
Article 550.13(A) Exception No. 3: Concealed NM cable is permitted where subject to contact with thermal insulation in a non-dwelling mobile home.
Therefore, it is permissible to use NM cable in concealed locations in non-dwelling mobiles, such as office complexes.
It is important to note that the exceptions in Article 550.13(A) only apply to non-dwelling mobile homes. Flag for review