If you've spent much time studying the NEC, you understand that Chapters 1 through 4 apply to all installations, except as amended for specific installations in Chapters 5 through 8. As with many rules, this one has exceptions. One such exception is Art. 210, which provides the requirements for sizing branch circuits. These requirements don't apply to motors [210.1]. Motor branch sizing requirements are in Art. 430.

So what about Art. 215? While Section 210.1 does refer you to Art. 430, Section 215.1 doesn't. So it would appear, at first glance, that you follow the requirements of Art. 215 to size the feeders for motors. But Section 430.1 says that Art. 430 provides the requirements for motor feeders. Figure 430.1 provides you with a motor system overview of Art. 430, and it shows motor feeders as being covered by Art. 430 Part II.

What is it about motors that you size their branch and feeder conductors in a different way from sizing for other loads? It's the fact that motors, being inductive loads, have a high (but momentary) inrush current. So instead of sizing a conductor so it's sufficient for the load being served [210.19A)(1)], you size it for 125% of the motor full-load current rating [430.22]. For the same reason, you also use a different approach to circuit protection.