The code only allows #12 to have a breaker rated at 20 amps so the temp would be lower than 60C.
If you have #12 TW with 25 amps continuous(3 hrs)with an environment temp of 30C then the conductor temp will rise to 60C.
I'm confused- I still don't think the temperature rating in the column headings tells me the temperature that the wire will get to when the specified ampere rating is on the wire. This really is my question that no one seems to answer, even UL have not answered me. I almost accepted the fact that it's a stupid question. I'm sure there is some kind of tolerance factors involved that allow the continuous load rating.
