If the motor current is less than 100A; so say you look up the FLC in 430.250 and it's 85A. Also, it is NOT marked with design B, C or D. Do you use the 60C or 75C column? According to 110.14(C)(1)(a)(4) "For motors marked with design letters B, C or D, conductors having an insulation rating of 75C or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75C ampacity."
So typically, if the motor is rated less than 100 A, I use the 75C column. But I just wanted to make sure that it does not necassarily need to be a design B, C or D.
Also, what column do you use if you apply continuous load (125%) and the current goes above 100A? So say you have a 95A continuous load. Would you look up the 60 or 75C column (since after adjustment, it's 95x1.25=119A). Same if it is more than 3 conductors or elevated temp...
Thanks
So typically, if the motor is rated less than 100 A, I use the 75C column. But I just wanted to make sure that it does not necassarily need to be a design B, C or D.
Also, what column do you use if you apply continuous load (125%) and the current goes above 100A? So say you have a 95A continuous load. Would you look up the 60 or 75C column (since after adjustment, it's 95x1.25=119A). Same if it is more than 3 conductors or elevated temp...
Thanks
