I thought I would bring this thread back to life.

I was told lately that double cable stapleing violated the bundleing rules.

Article 310.15.B.2.b says to derate conductors according to the number of current carrying conductors.

Say I have 3 cables, each a 3-wire #12. That gives me 9 current carrying conductors, which means I have to derate by 70%

Table 310-16 gives a #12 amp rating at 30 amps. 70% of 30 = 21amps. The maximum o.c. device on this size of wire is 20amp. Is the wire protected? Yes, so what is the problem?

I could do the same for 9 #14 wire (25amps X 70% = 17.5)

As long as I don't go over 9 current carrying conductors in a bundle, there is no problem, is there?

Anyone have problems with the bundleing rules as applied to nm cable?

I would like to forward this thread to the inspector who made this call, after I hear from you all on this.

Thanks in advance.

Rick Miell