1. Introduction HVD7 33KV 36kv outdoor HV AC vacuum circuit breaker VCB has many visual advantages like reasonable design, fashionable appearance, high safety and reliability, simple maintenance, long electric life. It is the ideal upgraded products of 35KV outdoor oil circuit breakers. HVD7-40.5 vacuum circuit breaker is applicable for three-phase power system of AC 50HZ.It is used to make and break the load current ,overload current and short-circuit current. 2. Applicable environment 3.1The ambient temperature should be -30degree~ +40degree(-40degree in the frosty area); 3.2Altitude should not exceed 2000m(over 2000m is plateau type); 3.3The wind pressure should not exceed 700Pa(equal to wind speed 34m/s); 3.4Air pollution degree: 3,that of antifouling type:4; 3.5The installation site should be free from the fire, explosion, chemical corrosion and serious vibration. 1. Main technical parameters Rated voltage: 33kv 36KV 1 minute power frequency withstand voltage, dry test: 95 kv 1 minute power frequency withstand voltage, wet test: 80 kv Lightning impulse withstand voltage(peak value): 185 kv Rated current: 1600A / 2000A Rated short-circuit breaking current: 20KA, 25KA, 31.5KA Rated short-circuit making current(peak): 50KA, 63KA, 80KA Rated operating sequence: O-0.3s-CO-180s-CO Rated short-time withstand current: 20KA, 25KA, 31.5KA Rated peak withstand current: 50KA, 63KA, 80KA Rated short-circuit duration: 4 s Rated control voltage: AC220,110;DC220,110 Rated short-circuit breaking current break times: 20 times Full-break time: