yet another bundling question

[backwaterdogs]

In routing nm in an insulated space, i.e. covered in insulation in an attic, is it permissable to 'stack' two nm cables and staple them to the top edge of 2x or a running board for more than 24"? I can't find in the code where it allows this but have been doing and passing...is this not budling cables?

thanks!

 

[allenwayne]

Bundling of NM comes to be when there are more than 9 current carrying conductors bundled together within a 24 in span.

 

[ryan_618]

I agree with Allen to an etxent. Bundling of 12, 14 or 10 AWG cables or conductors only becomes problematic when there are more than 9 current carrying conductors.

 

[bphgravity]

I agree with Ryan whom agrees with Allen.

 

[LarryFine]

I agree with Ryan, but I disgaree with Allen.

 

[pete m.]

If adopted as proposed for the 2008 NEC deration would apply in this situation (wiring in insulation) regardless of length of "bundling".

Where more than two NM cables containing two or
more current-carrying conductors are installed in contact
with thermal insulation without maintaining spacing between
cables, the allowable ampacity of each conductor
shall be adjusted in accordance with Table 310.15(B)(2)(a).
ROP 7-74

Pete

 

[celtic]

... maintaining spacing between
cables ....

What is the definition of "spacing"?

 

[ryan_618]

Well, you could go to the proposed definition of bundling in Article 100, if it passes.

 

[77401]

Attic insulation or not its not bundling
Its considered stapling.

 

[backwaterdogs]

Thanks for the clarification, everyone!