MCA hvac to size cable in code

[hhsting]

Where in code it says one can use MCA of condensing unit to size cable? If I have 60A breaker based on MOCP of 60A and MCA of 30A then my cable size would be #10 based on MCA but #6 based on 310

 

[LarryFine]

Start with 240.4(D), and then 240.4(G), then from there.

 

[Greentagger]

440.6; 440.6(A) Exception No 1