How do you calculate cable size for 50 hp?

Answer 1

First you need to find out the maximum current, for which you need to know the voltage.

Once you know the maximum current, cable manufacturer provides a data sheet in which you can find out the current carrying capacity of different size of cables. You can then choose right size of cable for current equivalent to 50 HP. It also depends on the way you plan to lay the cable - underground or over head, single or multi layer, ambient temperature , also the permissible voltage drop at the end of the cable... etc

Size will differ depending on whether the cable is copper or aluminum. Copper cable can take more current, compared to aluminum for the same size, generally