Derating wire exception in 2008 NEC code

[Tainted]

In NYC we are stuck with 2008 NEC with amendments.

In the updated code 310.15(B)(2)(a) exception it says "Adjustment factors shall not apply to conductors in raceways
having a length not exceeding 600 mm (24 in.)."

However in the 2008 NEC it does not say that. It only gives the exception for nipples and not raceways specifically: "Exception No. 3: Derating factors shall not apply to conductors in nipples having a length not exceeding 600 mm (24 in.)."

If I'm under the 2008 NEC, does this mean I still have to derate wires that are less than 24 inches in the raceway?

 

[infinity]

No. A nipple is a short section of raceway.

 

[Tainted]

No. A nipple is a short section of raceway.

I've always thought a nipple and a raceway are two different things.

What if the wire is less than 24 inches in a wireway? a wireway is not defined as a nipple?

 

[infinity]

Wireways have a different set of rules. Derating doesn't apply until you have more than 30 CCC's at a cross section.