Vacuum Circuit Breaker HVD7 40.5KV 1250A outdoor HV AC VCB from Hubei JUCRO Electric 1. Introduction HVD7 40.5KV 1250A 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 1250A 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 2.1The ambient temperature should be -30degree~ +40degree(-40degree in the frosty area); 2.2Altitude should not exceed 2000m(over 2000m is plateau type); 2.3The wind pressure should not exceed 700Pa(equal to wind speed 34m/s); 2.4Air pollution degree: 3,that of antifouling type:4; 2.5The installation site should be free from the fire, explosion, chemical corrosion and serious vibration.