1.General HVD85 ZN85 33kv 36KV indoor vacuum circuit breaker VCB is suitable for three-phase AC power system of 50Hz and 36kV, used to make and break the load current, overload current and fault current in industrial and mining enterprises, power plants and transformer substations, meanwhile, it is suitable for the occasion where the frequent operation is required. 2. Service conditions 2.1The ambient air temperature should be -15?~40?, the daily average temperature should not exceed 35?. 2.2 Daily mean relative humidity should not exceed 95%, and the daily mean vapor pressure should not exceed 2.2kPa; the monthly mean relative humidity should not be higher than 90%, and the monthly mean vapor pressure should not exceed 1.8kPa. 2.3 Altitude: Not exceed 1,000m. 2.4 The ambient air should be free from the dust, smoke, corrosive and flammable gas, steam, salt fog, et… Main specifications and technical parameters Rated voltage: 33KV 36kv Power frequency withstand voltage: 95 kv Lighting impulse withstand voltage: 185 kv Rated current: 1250A, 1600A, 2000A Rated short-time withstand current: 25KA, 31.5KA Rated peak value withstand current: 63KA, 80KA Rated short-circuit duration: 4 s Rated short-circuit breaking current: 25KA, 31.5KA Rated short-circuit making current: 63KA, 80KA Rated operation sequence: O-0.3s-CO-180s-CO Breaking time: