Sizing conductors 100a or less

[mstrlucky74]

So if the equipment is not marked you are to use the 60 degree Column or it could be marked 75 degree then that column would be used. How often is equipment 100a or less not marked or only marked 60 degree? I think just about all breakers are marked 75 degree. Thanks.

 

[augie47]

As I recall, some devices 50 amps and less are 60° but the 240.4(D) restriction pretty much takes care of the problem,

 

[infinity]

Pretty much all modern equipment is rated for 75 degrees C.

 

[lauraj]

Romex is limited to the 60C column. That's the only common case I can think of to ever be there.

 

[mstrlucky74]

Romex is limited to the 60C column. That's the only common case I can think of to ever be there.

Interesting so whenever sizing romex it's always the 60 degree?

 

[augie47]

Interesting so whenever sizing romex it's always the 60 degree?

Art 334.80

 

[jumper]

Interesting so whenever sizing romex it's always the 60 degree?

Except for derating using 90C, yes.