Once the full load current (FLC) rating of the motor has been determined, the branch circuit conductors can be sized. NEC^® Section 430.22 requires conductors that supply a single motor used in a continuous duty application to have an ampacity of at least 125% of the motor FLC.

At 460 - 480 volts, the motor has a FLC of 27 amps. Since the motor is marked as a continuous duty motor, the FLC must be multiplied by 125% as follows:

27 X 125% = 33.75 amps. This is the minimum circuit ampacity to supply the motor.

Refer to NEC^® conductor ampacity Table 310.16. If installing a type THWN copper conductor and terminating it at each end to 75°C terminals, a 10 AWG conductor rated at 35 amps would be sufficient as a branch circuit conductor.

See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to NFPA 70.