310.15b16

[Djelite]

The 90 degree column is used for ampacity of conductors. Does that apply to all conductors when you’re dealing with ampacity adjustments and corrections? Or due some conductors get adjusted to the 75 degree when dealing with ampacity?

 

[infinity]

If the conductors are 90° C conductors (THHN for example) you would use the 90° C ampacity for the adjustments. If you had a 75° C conductor like THWN then you would use the 75° C ampacity.