1000KVA/10KV transformer high-voltage side of the rated current 57.7A, according to the current counting only a very small cross-sectional area, but consider the dynamic thermal stability calibration, the 10KV bus fault level if 31.5KA, then the cable should be at least 70mm2, the transformer does not need a neutral line, if it is not directly buried (cable trench bridges), then the Select YJV(22,32)-6/10(8.7/15) 3*70mm2 can be, brackets for armored direct burial cable and high insulation level configuration.