What size wire for 3 phase 15 hp 480 volt motor?

For a 15 HP, 480-volt three-phase motor, you typically need to use 10 AWG copper wire or 8 AWG aluminum wire for short distances, based on the National Electrical Code (NEC) guidelines. However, if the distance from the power source to the motor is long (over 100 feet), you may need to use a larger gauge wire to account for voltage drop, potentially 8 AWG copper or 6 AWG aluminum. Always consult local codes and a qualified electrician for specific applications.