430.22 sizing

[chris kennedy]

430.22 states that my conductors shall have an ampacity of not less than 125% of the full load current rating taken from the tables.

Given I’m adjusting the ampacity to 125% can I use the 90C column as per 110.14(C)?

Thanks

 

[infinity]

After you add the 25% your conductor must have that minimum ampacity. If your terminals are rated for 75° C the conductor ampacity will be based on 75° C not 90°C.

If you need a 50 amp conductor and find one rated 50 amps @90° C but is only rated for 40 amps @75° C you cannot use it.