Correct!  (C) Table 310-13 in footnote # 5 states that THWN-2 shall be permitted to be used at a continuous 90 degree C operating temperature, wet or dry. This allows the 90 degree ampacity to be used for derating purposes, but the final load rating cannot exceed the 75 degree column per Section 110-14(c)(2). THWN without the –2 is only permitted to be used underground at the 75 degree ampacity and must be derated from this rating.

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