ECN Forum Forums Code Related Discussion NEC & other Code issues 90C Wire

The ratings of the lugs only are not what determines which temperature rating to use.
The only consideration is the rating of the termination of the entire device.

I am not aware of any overcurrent protective device that is rated for use with any wire sized smaller than the 75C column. During NRTL temperature rise testing, the wire is always used as a heat sink. Even 100% rated equipment requires the use of 90C insulation but it is still sized using the 75C column

I was noticing that pressure splices are rated at 90 degree.

Really bad but allowed practice:

We might have a 75 degree temiation, to a wire rated for the load at 75 degrees, to a pressure splices rated at 90 degrees, to a conductor rated for the load at 90 degrees ... on to the other end.