Further Clarification?
Further Clarification?
Thank you for all your responses. I wish I could reply to just one poster, but is difficult with all the mixed responses. Hopefully, if I present something a little more specific, this will help reveal the intent of my questions.
First, it is my understanding, or interpretation, that code 110.15(C)(1) only applies to unmarked equipment. If the equipment is marked with the termination ratings, then we know exactly how to size our wires.
For new commercial construction, is there any piece of equipment that is not marked, and not marked for at least 75* C? If there is no such equipment, why would I apply 110.15(C)(1) and size for 60* C, especially if the standard (or specifications) is to use THWN 75* C or THHN 90* C wire? I would be grossly oversizing my wire for the 90* C case.
This is what led to my question regarding upsizing the ground. This oversized wire can greatly increase the available ground fault current at the equipment, which is the very reason for 250.122(B).