On 3/3/13 8:46 PM, Mikepier wrote:

I understand what the article is saying, but at the very least,
shouldn't the 10 guage wire be on a 30A breaker and not 40A?

The rules are different for motors than on other things for what
it's worth. Wire is supposed to be sized at 125% of the full load
amperage shown on the appropriate chart. Overcurrent protection can be
175% of the value shown in the chart. One can go to the next larger
size if the 175% calculation puts one in between standard fuse or
breaker sizes.
This might not apply directly to air conditioners but I think the
code writer's reasoning is the same.