QUESTION ON 110.14 c

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dcv

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Isn't 110.14 C in direct conflict with 110.14 (1) (a)2 and 3
In other words let's say I'm using #12 THHN 90 degree wire (dry location) 6 curent carrying conductors in a 3/4" raceway.The way I read 110.14 c is that I can use the 90 degree column 310.16 for ampacity adjustment, which after derating per 310.15 b 2 a The ampacity of the wire would be 24amp
However when I read on 110.14 (1) (a)2 and 3 This tell me either use 60 degree column or 75 degree if the termination is rated as such. Now doing the same calculation above but using 75 degree column I'm at 20amp.

What am I missing one says I can use 90 degree column and the other tells me i can not.
 
For the purposes of derating, you can start with the value in the 90C column. The final ampacity that you actually use cannot be higher than the value in the 75C column (if the terminations are rated 75C) or higher than the value in the 60C column (if the terminations are only rated for 60C).
 
Thanks Charlie

Thanks Charlie

That make sense and that's kind of what I was thinking, however I don't understand how you read that out of these codes. I mean 110.14c clearly tells me the I can use the 90 degree column for the ampacity adjustment period.
It does not tell me to keep reading, there's a conflit or another adjustment coming up in the next code.
I see what your saying and It make sense to me now, but I would have disagreed with you if the statement 100amp or less and 14 To #1 AWG wire was missing from that section. I think this area of the NEC could have been worded a little less confusing.
 
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