I have installed larger equipment that has been 90C rated Square D 3000 amp breakers specifically.

Also when you need to do ampacity adjustments for temperature or number of conductors you can start with the 90C column. Once you do your derating you check the derated figure against the column for the temperature of the termination or wire you are using and use the lowest figure.


Bob Badger
Construction & Maintenance Electrician
Massachusetts