I believe Redsy is correct. Size the feeder circuit breaker at not more than:
- Largest motor FLA (per Table 430.52) X 250% (or the next standard size up)
plus,
- The full-load current of all other motors.
An additional consideration that I would recommend is to add a fusible disconnect at the HVAC unit. This provides a local disconnect for the unit to facilitate maintenance requirements and also may be needed if the unit requires protection from fuses...applying products according to their listing and labeling - NEC 110.3(B).
Some HVAC units indicate max overcurrent device, which can be protected by a fuse or circuit breaker. In this case a non-fused disconnect would work as the local disconnect(provided the fault current is not above 10kA, since most non-fused disconnects are not rated above that).
However, many indicate max fuse size. If this is indicated, fuse protection in accordance with the label must be provided. Many engineers I talk with always specify a fused disconnect at the HVAC for this reason.
