It addresses Metal-Clad Cable Type MC. This type of cable is a factory assembly
of insulated circuit conductors inside an armor of interlocking metal tape or
inside a metal sheath (smooth or corrugated) [330.2]
You can use
Type MC cable in a dozen different defined general applications [330.10(A)]. One of
those, wet locations, is permissible only if the particular Type MC being
considered meets one of three conditions. Article 330 lists four specific uses
for Type MC Cable [330.10(B)]: Cable tray, direct buried, service entrance
cable, and outdoor aerial cable.
can't use it where it's subject to physical damage or where exposed to corrosive
factors it's not designed to handle [330.12]. Regarding the physical damage,
Type MC Cable, while inherently very strong, is not as strong as a solid conduit
such as RMC or IMC. But it is lighter and usually easier to install and has
other benefits that make it suitable for many applications in place of RMC or
IMC. It fills a niche between these stiff-walled conduits and lighter duty
answering that question, it's worth noting that the support issue is moot if you
damage the cable during installation by exceeding its bend radius [330.24].
Generally, you must support the cable every 6ft (or less) using approved support
methods that don't damage the cable [330.30(A), (B), (C)]. But you don't have to
support this cable if it's fished between access points in concealed spaces of
finished structures, supporting is impractical, or it's running to a luminaire
(or other equipment) and is less than 6ft from the last support [330.30(D)].
You can use
any terminations suitable for the conductors. You must use fittings listed and
identified for use with Type MC Cable [330.40].