I want to determine the cable size,type?

Question

6.6 kv 3 ph 50 Hz Supply -->Vaccum Circuit breaker =========Soft starter ===== Induction motor {6.6 kV 750 Kw 2 Pole , 71 A}
( ==== ) This is Cable to be selected

Answer 1

4 awg MTW, THWN or THHN will carry 85 amps but the fact that it is on a motor you might need a special type of wire.

Answer 2

Although 4 gauge wire will carry the current, standard THHN and similar wire is rated for only 600 volts, so you will need special wire rated for the higher voltage. But I don't understand the reference to 2 pole -- do you mean 3?

Answer 3

It sounds as though you need a metric sized cable......
Therefore, assuming that the PF is .8 the FLA of the motor would be around 80A at 6.6kV.
3 x XLPE/PVC single core cables in air, for say 50m route length would be 16mm². (in conduit & underground ducts 25mm²)(direct buried 16mm²).

Hope this helps