50 kilowatts of electricity to protect the ground wire to how many square wires

Hello, 50 kilowatts of electrical equipment, the use of three-phase four-wire power supply, the current is about 100A.

Power supply distance if the 30 meters or less, the cable cross-section is recommended to choose 3 * 35 + 1 * 25 square. So the cross-section of the ground wire is not less than one-half of the phase wire is enough, you can choose 25 square.

The above is for reference only.