Code:
[B]334.80 Ampacity[/B] ... Where more than two NM cables containing two or more current-carrying conductors are installed, without [I][B]maintaining spacing[/B][/I] 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.
Where more than two NM cables containing two or more current-carrying conductors are installed in contact with thermal insulation without [I][B]maintaining spacing[/B][/I] between cables, the allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a).
Where is the spacing between cables that must be maintained defined?