When the HVAC manufacturer's list MCA, minimum circuit amps, for a unit, does this number already include the 25% extra required by NEC for feeder sizing?
MCA does not necessarily include the full 25% markup on continuous load. The manufacturer takes the evaporator fan, the condensor fan, and the compressor and adds them together. They then add 25% for the largest motor of the group which is almost always the compressor. This number is called the MCA. So if you take the MCA and multiply by 80% you will not get the correct full load amps.
Feeder motor loads only need to include 125% of the single largest motor supplied, not all MCA's. As mentioned in the previous post, 80% of MCA is not necessarily FLA.
