Re: Short Plenum Run Question

["Theron" <scary_penguin@xxxxxxxxxxx>]

robertlbass@xxxxxxxxxxx wrote:

. . .

> The NEC defines a plenum as a "compartment or chamber to which one or
> more air ducts are connected and that forms part of the air
> distribution system."
>
> Regarding wire and cable in ducts and plenum spaces, the code states:
> "Only wiring methods consisting of Type MI cable, Type MC cable
> employing a smooth or corrugated impervious metal sheath without an
> overall nonmetallic covering, electrical metallic tubing, flexible
> metallic tubing, intermediate metal conduit, or rigid metal conduit
> without an overall nonmetallic covering shall be installed in ducts or
> plenums specifically fabricated to transport environmental air."

. . .

Thanks for your help, Robert (and everyone).  If I can, I have one more
code question.  In Chapter 300, there's an exception to the rule for
wires that travel through studs or joists perpendicular to the stud or
joist.  (I apologize for not having an exact citation - I don't have
the code here).

I assume that I don't fall within that exception, because it wouldn't
make sense, but I can't quite figure it out.  Do you know what the code
authors are trying to refer to with that section.