NEC table 310.15(B)(16) and wireways

[Tainted]

All my life I have been using table 310.15(B)(16) to size wires that are going into a wireway...

Wireways are allowed to have 30 CCC without derating but how come we are allowed to use this table if this table is for "Not More Than Three Current-Carrying Conductors in Raceway"? By definition a wireway is a raceway.

 

[wwhitney]

Note 2 to Table 310.15(B)(16) (2020 NEC) says "Section 310.15(C)(1) shall be referenced for more than three current-carrying conductors." So the Note expands the applicability of the table to beyond what is in the title.

But section 310.15(C)(1) has no exception for wireways, so apparently the allowance of 376.22 is useless. Seems like an oversight.

Cheers, Wayne

 

[don_resqcapt19]

Note 2 to Table 310.15(B)(16) (2020 NEC) says "Section 310.15(C)(1) shall be referenced for more than three current-carrying conductors." So the Note expands the applicability of the table to beyond what is in the title.

But section 310.15(C)(1) has no exception for wireways, so apparently the allowance of 376.22 is useless. Seems like an oversight.

Cheers, Wayne

Just an example where a rule in one Chapter 3 article is intended to amend a rule in another Chapter 3 article, but there is no provision for that th happen in 90.3. However, I am not aware of any AHJ not permitting the applications of the provisions of 376.22(B) for wireway conductor ampacity adjustments.