Perhaps... based on 310.15(B)(2)(a) where it states...More than 3 wires in a conduit requires ampacity adjustment. Is conductor ampacity adjustment ever required for wires inside an Industrial Control Panel?
However, this requirement should never apply because of another requirement......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)(2)(a).
The intent here is to not have conductors all bunched together. However, note the requirement is for sufficient space, not the distribution of conductors within that space.312.7 Space in Enclosures. Cabinets and cutout boxes shall have sufficient space to accommodate all conductors installed in them without crowding.
I don't know, because it does. Article 366 does not.Why would this not fall under article 409?
Again, nothing directly relating to ampacity adjustment... and also another requirement which places conditions on space for wires but nothing about distribution of wires within that space.Assuming control panel is 600V or less, only thing I see is 409.104.
Why not? In my opinion 310.15(B)(3) applies to panduit if the installation is covered by the NEC, however the Exception to 310.15(A)(2) will in many cases eliminate the need to derate in the panduit..... Nor do you derate for wires in the 'Panduit' troughs. ...
In my opinion the words in bold would apply to power or lighting conductors installed in a panduit wireway. In many cases the conductors in the panduit would be not be power or lighting conductors and derating would not be required.(3) Adjustment Factors. (a) More Than Three Current-Carrying Conductors in a Raceway or Cable.
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.
Where conductors of different systems, as provided in 300.3, are installed in a common raceway or cable, the adjustment factors shown in Table 310.15(B)(3)(a) shall apply only to the number of power and lighting conductors (Articles 210, 215, 220, and 230).