So is it for branch circuits or feeders?
220.50(B) is in part III of 220 "service and feeder calculations" and it says to use part IV of article 440 conductor sizing requirements to determine the loads for the feeder.
220 part III is using the values from 440.34 in part IV of 440. So 220 is modifying 440 part IV in a sense, especially 440.32 where it uses 'branch circuit conductors' in the rare case you have a feeder or service with only a single motor-compressor load.
If it's for branch circuits, how does a branch circuit feed AC, lighting and other loads?
A packaged HVAC system could have field installed electric resistance heat strips and a fan motor. A tech can interchange with components of different values and this could all be on 'one branch circuit'.
Mitsubishi only gives you MCA. They tell me to calculate FLA by multiplying MCA by 0.8. I find that inaccurate.
Well the NEC 440 and UL 1995 Clause 44.3 requires the equipment to be 'plainly marked', in a permanent manner, with the following:
a) The manufacturer's or private labeler's name, trademark, tradename, or other identifying
symbol;
b) The catalogue number, style, model, or other type designation;
c) Voltage;
d) Number of phases, unless for single-phase operation;
e) Frequency in hertz;
f) The horsepower (see Clause 44.17) and
full load amperes (FLA) of each motor, except for hermetically sealed compressor motors, which shall be rated in locked rotor and
rated load amperes (RLA) (see Clause 44.10), and motors smaller than 1/8 horsepower, which may be rated in watts or amperes;
( there are exceptions for VFD motors that allow Maximum Operating Current (MOC) )
g)
Heater input amperes or watts at marked voltage. See also Clause 44.3(t) for separable heater element assemblies