Conductor Derating

[romex jockey101]

thats why i thought your only allowed 3 nm wire assembles through the same hole of a framming member..

 

[dana1028]

thats why i thought your only allowed 3 nm wire assembles through the same hole of a framming member..

You're allowed 4 NM [12/2, 14/2, etc. - with a total of 8 CCCs] before the derating requirements of T310.15(B)(2)(a) reduce the ampacity values of the conductors too much [i.e. a 12/2 would only have a 15A value, 14/2 = 12.5, etc.]

 

[infinity]

You're allowed 4 NM [12/2, 14/2, etc. - with a total of 8 CCCs] before the derating requirements of T310.15(B)(2)(a) reduce the ampacity values of the conductors too much [i.e. a 12/2 would only have a 15A value, 14/2 = 12.5, etc.]

If you had MWBC's (like exiting a panel) you could get 4-12/3 or 4-14/3 NM cables in that hole.