We adopts differential protection as main protection of power transformer (SST #AA,SST #AB). Generally, inrush current is 6~8 times the rated current of transformer. And we can find that the original value of 1604 is 5.5 times the rated current of transformer.We just input the rated current transformers value in both side of the transformer into the differential protection relay, and there is no need to adjust the value of 1604.