Nec 310.15

[clsarmiento]

Can I use the 90degreeC column of table 310.16 for the conductor ampacity in derating/correction factors due to higher ambient temperatures? What about the termination markings, are 90degreeC ratings readily available?

 

[roger]

Can I use the 90degreeC column of table 310.16 for the conductor ampacity in derating/correction factors due to higher ambient temperatures?

Yes you can and you should.

What about the termination markings, are 90degreeC ratings readily available?

Generally speaking, 90 deg rated equipment is pretty rare and is only available in some larger equipment.

Roger

 

[jim dungar]

... are 90degreeC ratings readily available?

No, absolutely not.

Actually, UL does not list any 600V equipment for conductors sized using the 90?C column, until you get into industrial switchgear(what is often called ANSI or drawout gear).