How to calculate the short-circuit current and setting current for a circuit breaker?

Regarding the rating of the machine, it is quite clearly described in PUE 3.1.4:

“The rated currents of fuse-links of fuses and the setting currents of circuit breakers used to protect individual sections of the network should in all cases be chosen as low as possible according to the rated currents of these sections or by the rated currents of power receivers, but so that the protection devices do not shut off electrical installations during short-term "overloads (starting currents, peaks of technological loads, currents during self-starting, etc.)."

The length of the line is given to you to calculate the short-circuit current, perhaps some transformer parameters or its name are also indicated in the substation data.

Details of the calculation are written in the guidelines “Calculations of short-circuit currents in 0.4 kV networks”, author - I. Nebrat Organization - St. Petersburg Energy Institute of Continuing Education ”- according to these data, you can easily find them on the network.

And there is another document, in my opinion it describes the essence of the issue more simply:

STO DIVG-058-2017 "Calculation of currents of short circuits and earth faults in distribution networks" LLC "Scientific and Technical Center" Mechanotronika "