What size in mm of cable on 1100 amps?

The appropriate cable size for carrying 1100 amps depends on several factors, including the type of insulation, installation conditions, and permissible voltage drop. Generally, for copper conductors, a cable size of around 300 mm² is often recommended for this current level in a typical installation. However, it's crucial to refer to local electrical codes and standards or consult with a qualified electrical engineer to ensure safety and compliance.