MI conductors ampacity ratings

[NOV]

Do circuits using MI cable fall under the same rules for terminations as THHN? In other words, the rating of the cable can only be as high as the rating on the lugs it is terminated on, correct? Or am I overlooking a section in the NEC that says otherwise?

 

[Coppersmith]

I believe MI cable has a 90C rating. You use the ampacity at 90C for doing derating calculations. However if you are going to land the cable on lugs that are rated 75C, you will have to reduce the ampacity to the 75C rating (possibly requiring a larger size wire) if it is higher after the calc. If you are landing on 90C lugs, then you can use it as is.

 

[NOV]

Thank you for confirmation, that is how I understood it also but wanted to be sure I wasn't missing something.