The positive, negative and zero sequence impedances of a 125 MVA, three-phase, 15.5 kV, star-grounded, 50 Hz generator are  and  respectively on the machine rating base. The machine is unloaded and working at the rated terminal voltage. If the grounding impedance of the generator is  then the magnitude of fault current for a b-phase to ground fault (in kA) is _______ (upto 2 decimal places).