A three phase transformer has a name plate details of 30 MVA and voltage rating of 230Y kV/69∆ kV with a leakage reactance of 10% and the transformer connection via wye-delta. Taking a base of 230 kV on the high voltage side, the transformer reactance referred to the low voltage side in ohms is

Correct Answer: 0.1
XΩ(LV) = XΩ(HV) /n2 = 176.33/(230/69)2 =15.87 Ω Xpu= 15.87/158.7 = 0.1.