See Article 366 and Article 376.

You are allowed a 20% fill and up to 30 current carrying conductors. If you exceed 30 conductors, you have to do the derating per table 310.15(B)(2)(a)

Essentially, they are the same thing, they just differ in how they are used.

Tom

[This message has been edited by Tom (edited 12-06-2004).]

[This message has been edited by Tom (edited 12-06-2004).]

Few things are harder to put up with than the annoyance of a good example.