chris.mcnamara
Member
- Location
- San Francisco, CA, USA
Hey All
Im a little confused about some language in section 310.15(B)(3)(a).
The code reads:
(a) More than Three Current-Carrying Conductors. Where the number of current-carrying conductors in a raceway or cable exceeds three, or where single conductors or multiconductor cables are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.) and are not installed in raceways, the allowable ampacity of each conductor shall be reduced as shown in Table 310.15(B)(3)(a). Each current-carrying conductor of a paralleled set of conductors shall be counted as a current-carrying conductor.
does the code ever define what "maintaining spacing" is? Is it a 1 cable diameter spacing? something else?
My company would like to bundle some type NM multiconductor cables (romex) to create a harness for faster install in residential dwelling units. I have advised that derating factors will be applicable to these cables if we do not "maintain spacing" but I can't define what the required spacing is.
Any help would be greatly appreciated!
Thanks
Im a little confused about some language in section 310.15(B)(3)(a).
The code reads:
(a) More than Three Current-Carrying Conductors. Where the number of current-carrying conductors in a raceway or cable exceeds three, or where single conductors or multiconductor cables are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.) and are not installed in raceways, the allowable ampacity of each conductor shall be reduced as shown in Table 310.15(B)(3)(a). Each current-carrying conductor of a paralleled set of conductors shall be counted as a current-carrying conductor.
does the code ever define what "maintaining spacing" is? Is it a 1 cable diameter spacing? something else?
My company would like to bundle some type NM multiconductor cables (romex) to create a harness for faster install in residential dwelling units. I have advised that derating factors will be applicable to these cables if we do not "maintain spacing" but I can't define what the required spacing is.
Any help would be greatly appreciated!
Thanks