VD4 medium-voltage indoor vacuum circuit breaker is applicable for three-phase AC power system of rated voltage up to 7.2kV~24kV and frequency 50/60Hz, widely used in many fields such as power plant, transformer substation, petrol chemical industry, metallurgy , manufacturing industry, airport, residential area, etc., to control and protect the electric equipment.
Especially, It is used for the occasion that needs infrequent operation at rated current or multi-breaking short circuit current, may be mounted in the indoor air insulating switchgear like type KYN28 or KYN96, ABB type ZS series, etc.

Application Environment:
1. Air temperature: Maximum temperature: +40℃; Minimum temperature: -25℃.
2. Humidity: Monthly average humidity 95%; Daily average humidity 90%.
3. Altitude above sea level: ≤2500m
4. Ambient air not apparently polluted by corrosive and flammable gas, vapor etc.
5. No frequent violent shake.