What is power cable size 10kW 3 phase motor with 415V?

The formula for amps when kilowatts are stated is; kW x 1000/1.73 x Volts x pf.

10 x 1000/1.73 x 415 x .8 = 10000/574 = 17 amps.

The electrical code states that motor feeders have to be rated at 125% of the motors FLA (full load amps). 17 x 125% = 21 amps.

A #10 copper conductor with an insulation factor of 75 or 90 degrees C are both rated at 30 amps.