insulation vs amp rating

[bill@usps06492]

When calculating a feeder load, and determing the proper size conductor, should you be rating the maximum amp carrying capacity using the 75c in table 310.16. It's been my understanding that the reason for doing this is because the termination rating for most equipment is rated at 60c&75c. This makes a big difference in the cost of a job because of the increase of the wire size , pipe, etc... Has anyone else run into this issue???
Bill

 

[boater bill]

You must use the rating of the lowest component in the system, whether it is lugs or wire for your ampacity calculations.

If someone else is bidding against you and not bidding to Code, let the owner know this so you get the job by being the best!