# 310.15



## McClary’s Electrical (Feb 21, 2009)

If you had 90 degree lugs on both ends you could use that column.


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## don_resqcapt19 (Jul 18, 2010)

gongolfen said:


> Can someone explain better than mike Holt exactly why there is a THHW in the 75° column and in the 90°? He just states to use the 90° unless it specifically calls for wet location. But they are both good for wet locations....


THHW is good for 75°C in wet locations and good for 90°C in dry locations only. See Table 310.104(A)


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## don_resqcapt19 (Jul 18, 2010)

mcclary's electrical said:


> If you had 90 degree lugs on both ends you could use that column.


Only if the equipment that the lug is connected to is also rated for 90°C, and that is not very common to find.


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## gongolfen (Mar 18, 2015)

I was under the assumption that any W was for Wet locations. So now I have to consult 310.104(A) before any calculation or test question pertaining to a wire with a W?


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## Dennis Alwon (May 9, 2009)

W does mean wet but depending on the wire it may only be rated 75C in wet location but 90C in dry location, as Don mentioned.

Some insulations such as Thwn-2 is good at 90C in both wet and dry locations


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## gongolfen (Mar 18, 2015)

Thanks guys


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