Cables Selection

[homeboyworkshop]

Hi there...Help..
Recently , I'm doing some automation project's part list selection . I found worry about what type of cable is suitable for my automation machine . This machine required 3 phase 400V (around 70A application) . Problem encounter as below :
1. Is any calculation is needed to select accurately the cables size?
2. Which type(material) of cables is preferred?

Thanks...