[Question] Correct Cable Sizing

[pmrindel]

I am upgading the electricity supply to our factory. (through City Power) According to my electrician, a 125mm cable is needed, 800amp breaker at the sub and 600 amp breaker at our main board. Now, City Power tells me that a 75mm cable is sufficient. A little internet reading says 213 amps for 75mm cable, is this per phase of the total amps? If for the cable then it's too small...

Any advice would be much appreciated as this is way above my pay grade. I don't want to be in a position of paying for the upgrade and power being supplied is not enough.

[GCE]

Not everything makes sense in the above but can only assume it is main sub upgraded to 800amp to allow your factory to take 600Amp and that CB feeding your cable to your DB is 600 Amp
Cable size is dependent on distance, exposure to sunlight , in trench, in sleeves , cable tray etc

At 600Amp I would say no less then 2 x 185sqmm 4 core but dependent on the above