It depends Omer. It will depend on the completion of circuit path for zero sequence currents. In case of a star connected winding,the zero sequence currents will flow only if star is grounded (Neutral) and there is a path to ground or 4th wire. If there is no path to ground or 4th wire in this particular winding and the other winding of the Xmer possess zero sequence current then; this winding will show zero sequence voltage in it but no current. This is due to induction property of Transformer. Hope I make it clearer to you. Please refer to zero sequence representation of different Xmers- you will get an idea, if the current will be flowing or not.
