Originally Posted by Bob Badger
You should really pick up the code book and read the sections I quoted.
(C) Other Space Used for Environmental Air.
applies to space used for environmental air-handling
purposes other than ducts and plenums as specified in
300.22(A) and (B). It does not include habitable rooms or
areas of buildings, the prime purpose of which is not air
FPN: The space over a hung ceiling used for environmental
air-handling purposes is an example of the type of other
space to which this section applies.
Exception: This section shall not apply to the joist or stud
spaces of dwelling units where the wiring passes through
such spaces perpendicular to the long dimension of such
(1) Wiring Methods.
The wiring methods for such other
space shall be limited to totally enclosed, nonventilated,
insulated busway having no provisions for plug-in connections,
Type MI cable, Type MC cable without an overall
nonmetallic covering, Type AC cable, or other factoryassembled
multiconductor control or power cable that is
specifically listed for the use, or listed prefabricated cable
assemblies of metallic manufactured wiring systems without
nonmetallic sheath. Other types of cables, conductors,
and raceways shall be permitted to be installed in electrical
metallic tubing, flexible metallic tubing, intermediate metal
conduit, rigid metal conduit without an overall nonmetallic
covering, flexible metal conduit, or, where accessible, surface
metal raceway or metal wireway with metal covers