NEC 430.22 VS UL508A General Use

[Ericthevikingtoo]

To the best of my understanding; per NFPA70 Article 430.22 motor circuit power conductors should be based on the 125% rule. UL508A Part 1 General Use Article 29.6.1 negates to specify this requirement for internal panel power conductors in a motor circuit. While a panel may comply with UL508A General Use per 29.6.1 - by not applying the 125% rule, is this not in violation if NFPA70 Article 430.22?

 

[petersonra]

To the best of my understanding; per NFPA70 Article 430.22 motor circuit power conductors should be based on the 125% rule. UL508A Part 1 General Use Article 29.6.1 negates to specify this requirement for internal panel power conductors in a motor circuit. While a panel may comply with UL508A General Use per 29.6.1 - by not applying the 125% rule, is this not in violation if NFPA70 Article 430.22?

A listed device has its on rules. For one thing, UL508a panels are only rated to 40 Deg C. So using 90 Deg C wire you have some play. In any case, the wire is more or less in free air inside the cabinet.

Personally, I do not use this dispensation since it confuses people. Better to size the wire per the NEC rather than save a few pennies on wire and spend $200 in engineering time explaining why it is OK.