NEC vs. UL508A - when to use?

[overkill94]

I work as a third-party inspector and I was trained to use the NEC in conjuction with UL580A when inspecting a piece of equipment. The more I dig into it, though, it seems that they are at odds with each other in certain respects (conductor ampacity for one).

My general question is - when inspecting a piece of equipment in the field (as an example let's just say it's a conveyor system) is there any use for the NEC or should UL508A take precedence when looking inside the panel?

 

[petersonra]

I work as a third-party inspector and I was trained to use the NEC in conjuction with UL580A when inspecting a piece of equipment. The more I dig into it, though, it seems that they are at odds with each other in certain respects (conductor ampacity for one).

My general question is - when inspecting a piece of equipment in the field (as an example let's just say it's a conveyor system) is there any use for the NEC or should UL508A take precedence when looking inside the panel?

I am not aware of anyplace where UL508a allows different ampacities. They are the same as in the NEC tables. A while back there were some minor differences just as there were in NFPA79 but that was "harmonized" maybe ten years ago.

In any case, NEC is an installation standard. UL508a is an equipment standard.