Wiring with return air chase

[Richard W. Washington]

Here is some wiring that in a 1970's home that was installed in the return air chase. Since the return is considered a combustion area is there a particular kind of sleeve that the wiring can be wrapped in to protect it?

[rbero]

section 300.22 B of the National Electrical Code 2005 states that only wiring of type MI or MC shall be permitted in ducts or plenums specifically designed for enviornmental air

[Paul W. Abernathy]

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
spaces.

[Paul W. Abernathy]

Ronald,

300.22(B) would not be what is pictured. At best 300.21(C) is the reference here and while Picture #1 would tend to be in accordance with the exception I posted. I am not sure picture #2 is....BUT with that said it would be close enough to compliance that I would not have a problem with it. If indeed we are talking about a dwelling unit and a return air space.