Are you refering to the neutral conductor as a current carrying conductor?
334.80 Ampacity.
Where more than two NM cables containing two or more current-carrying conductors are installed, without maintaining spacing between the cables, through the same opening in wood framing that is to be fire- or draft-stopped using thermal insulation, caulk, or sealing foam, the allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a) and the provisions of 310.15(A)(2), Exception, shall not apply.
I don't. Three or more cables, though, and I use stackers.So how many contractors or inspectors derate 2 NMs that are under the same staples that run the length of a stud according to 310.15b2a?
Not in every case case, such as using two 2-cond NM's between a pair of 3-ways as hot and neutral as well as a pair of travelers. Besides, not all conductors carry their ampacities.... wouldn't 2 NMs bundled be 4 current carrying conductors ...
For example, there could be a 14-2 cable feed down to a 3-gang box and three 14-2's coming back up to hit three fixtures. The most the entire bundle would ever carry is 15a.
No, just that it ought not. Or rather, need not.Are you saying this configuration would not require derating if bundled more then 24"?
No, just that it ought not. Or rather, need not.