NM Cabling exceeding 3 floors

[aw]

The 1999 NEC specifically prohibits the use of NM cabling in a mulitfamily dwelling or other structure exceeding three floors. 336-5(a)(1).
I cannot find a similar requirement in the 2002 NEC 334-12(A)(1) although the index under Nonmetallic sheathed cable refers you to this section. What's up with that?

 

[bphgravity]

Re: NM Cabling exceeding 3 floors

What the NEC did is change the three floor rule to what type of building construction type NM can be installed in. This is specified under 334.10. Annex E of the 2002 shows the characteristics of they different building type classifications. The bottom line is fire ratings of different construction types.

 

[don_resqcapt19]

Re: NM Cabling exceeding 3 floors

The code was changed to permit NM in structures that are not required to be of fire resistive construction and that exceed three floors above grade. If you are using NM you need to take a very close look at 335.10 and 334.12. There are a number of changes from the '99 code.
Don