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334.15 Exposed Work
In exposed work, except as provided in 300.11(A), cable shall be installed as specified in 334.15(A) through (C).
(C) In Unfinished Basements Where cable is run at angles with joists in unfinished basements, it shall be permissible to secure cables not smaller than two 6 AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables shall be run either through bored holes in joists or on running boards. NM cable used on a wall of an unfinished basement shall be permitted to be installed in a listed conduit or tubing. Conduit or tubing shall utilize a nonmetallic bushing or adapter at the point the cable enters the raceway. Metal conduit and tubings and metal outlet boxes shall be grounded.
Section 334.15(C) was changed for the 2005 Code. The means of providing physical protection in 334.15(B) is now a more specific list of the required protection techniques. Notice that rigid nonmetallic conduit, Type RNC, Schedule 40 is omitted from this list unless it is judged as an ``approved'' means by the authority having jurisdiction (AHJ). Also, where NMC is installed close to the surface in masonry, concrete, or adobe-type construction, physical protection must be afforded to the cable by using steel plate?type protectors.
For exposed work in unfinished basements, as described in 334.15(C), physical protection for nonmetallic-sheathed cables run on unfinished walls can take the form of any listed conduit or tubing (including rigid nonmetallic conduit, Type RNC, Schedule 40).
