310.15(A)(2) Applies In Panelboards?

[infinity]

Throw in large junction boxes, wireways, switchboards, panels, trenches, etc. and you can see that there are many inconsistencies in the way this is written. IMO it needs a re-write. :happyyes:

 

[Dennis Alwon]

Aux gutters and wireways do not require derating for number of conductors if there are not more than 30 current carrying conductors. They also have a 20 percent fill requirement where raceways is 40 percent fill.

Where wiring space in a panelboard is used as a wireway pretty much same rules apply.

Can you call the space in the panelboard the same as a wireway? Maybe not. There are some similarities though.

There is no doubt an issue here or there could be. As Bob stated there would be a rare or perhaps unusual situation where it may affect the wiring.

I think the nec could be clearer but I bet it won't touch this issue unless the conductors are clearly bundled.

With the new code we now have panels that re 60 circuits with a possibility of 120 CCC.................. What a mess that could be.