A factory is supplied from a substation containing two 500 kVA, 11 kV/400 V transformers connected in parallel, each having a reactance of 0.08 pu. A 750 kVA generator with 0.12 pu reactance also supplies the 400 V busbars which in turn supply a 400 V feeder having an impedance of (0.01 + j0.015)Ohm /ph.
Calculate the short-circuit current in the feeder and the voltage of the 400 V busbars when a symmetrical three-phase fault occurs at the far end of the feeder. That fault level of the 11 kV system is 100 MVA.