Derating wires per terminal temperature ratings

[andrewpineo]

I have a 600V 80A disconnect with terminals temperature rated for 60C located inside a control enclosure. I contend that I need to use the 60C column and 2AWG wires on the load side while someone else says according to UL they can use the 75C and get away with 4AWG. Who is correct?

 

[charlie b]

Neither of you is correct, but you are closer. Your viewpoint is confirmed in article 210.14(C). But why did you pick #2, when #3 has a 60C ampacity of 85 amps?

 

[andrewpineo]

Neither of you is correct, but you are closer. Your viewpoint is confirmed in article 210.14(C). But why did you pick #2, when #3 has a 60C ampacity of 85 amps?

Only because the last time I went to the local supplier for 3AWG I found he doesn't usually carry the odd sizes for some reason.

 

[infinity]

When connecting to the 60° C terminals you would need to size your conductors for an ampacity of 60° C.

 

[Smart $]

... Your viewpoint is confirmed in article 110.14(C). ...

FIFY