... switchgear is used in the AC 3-10 KV three-phase 50 Hz single bus power system to receive and distribute the ... frequencyHz50/60Rated insulation level1 min power frequency withstand voltageKV42 (isolation fracture: 48)Rated lightning impulse withstand voltage75 (isolation fracture: 85)Rated ... making currentKA50, 63, 80,100,130,160Rated short-time withstand current (4S)KA20, 25, 31.5,40,50,63Rated ...