... Indoor high voltage switchgear, Applies to rated voltage 12kv, frequency 50Hz three-phase power system,Electrical protection ... , box-type variable, or a variety of non-standard power supply system.The use of ... parametersNOItemUnitsparameters1Rated voltageKV122Rated insulation levelRated Lightning Impulse voltage toleranceKV751min Frequency voltage423Rated short-circuit breaking currentKA20/2531. ...