PCE 2017 Day 2 Paper 1 (Electrical) Q7 SC Calculation

Q7. Calculation of fault current… What is the prospective short circuit current  at the end of a 100m, 70mm2, 4C cable connected to a secondary of a 1500 kVa Transformer, 11/0.4 kV, 5.65% Z. The cable reactance is 0.0751 ohm/km and the resistance is 0.3342 ohm/km. The Utility SC level is 50kA at the primary side of the transformer.

1. Answer 1 (Based on IEC 60909 definition for PSCC)

So what is prospective short circuit current? (IEC 60909)
1.3.3 Prospective (available) short-circuit current
Current that would flow if the short circuit were replaced by an ideal connection of negligible
impedance without any change of the supply

This is one KBAT question for Malaysian Professional Electrical Engineers.

The calculation below is to ultimately calculate the peak current or making current, most websites define the prospective short circuit current as the peak current. However, those definitions kind of differ from the IEC 60909 definition for PSCC.