For more information on this please visit
A4-1 Short Circuit
Short circuit studies are an important study branch when designing electrical systems.
Parameters
s = apparent power (va). This is the total, complex power required to deliver the real power.
v = volts. Either line or phase voltage depending if it is a polyphase system.
z = impedance. Impedance in per unit of the system apparent power.
i = amps. Line current.
Enter at VA, Voltage and impedance to work out the rest