I Forget what the UL testing consists of breakers with a specific length of rater wire at each end. And, yes, wire servers as a heat sink to some extent as to not add heat to the breaker. NEMA AB4 Guidelines for Inspection and Preventive Maintenance of Molded-Case Circuit Breakers, has a good description for how testing breakers is done. (I had a copy but misplaced the darned thing or I would have scanned the page and attached it.)
With 100% rated breakers as has been previously stated 90degC rated wire muct be used but applied at 75degC and the UL test are do to assure that the breaker maintains the temperature rise as designed. As such its the testing that's the issue. As long as it is UL listed.
The immportant thing is to follow the manufacturers instructions for the installation for cable and the enclosure required for application at 100%.
With 100% rated breakers as has been previously stated 90degC rated wire muct be used but applied at 75degC and the UL test are do to assure that the breaker maintains the temperature rise as designed. As such its the testing that's the issue. As long as it is UL listed.
The immportant thing is to follow the manufacturers instructions for the installation for cable and the enclosure required for application at 100%.
