334.15(C) In Unfinished Basements and Crawl Spaces. Where cable
is run at angles with joists in unfinished basements and crawl
spaces, 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. Nonmetallicsheathed
cable installed on the wall of an unfinished basement
shall be permitted to be installed in a listed conduit or tubing
or shall be protected in accordance with 300.4. Conduit or
tubing shall be provided with a suitable insulating bushing or
adapter at the point the cable enters the raceway. The sheath of
the nonmetallic-sheathed cable shall extend through the
conduit or tubing and into the outlet or device box not less
than 6 mm (1∕4 in.). The cable shall be secured within 300 mm
(12 in.) of the point where the cable enters the conduit or
tubing. Metal conduit, tubing, and metal outlet boxes shall be
connected to an equipment grounding conductor complying
with the provisions of 250.86 and 250.148.
