++++General:
     VD4 medium-voltage indoor vacuum circuit breaker is applicableforthree-phase  AC power system of rated voltage upto 7.2kV~24kV andfrequency 50/60HZ,widely used in manyfields such as power plant, transformer substation, petrol chemical industry , metallurgy , manufacturing industry , airport, residential area, etc., to control and protectthe electric equipment, especially , It is usedforthe occasionthat needs infrequent operation at rated current or multi-breaking short circuit current, may be mounted inthe indoor air insulating switchgear like type KYN28 or KYN96,  ABB type ZS series, etc. This circuit breaker is standards asGB1984-2003  AC high voltage circuit breaker ,JB3855 3.6-40.5Kv indoor  AC High voltage circuit breaker ,DL/T403 Specification of 12-40.5Kv indoor High voltage vacuum circuit breakerfor order as well as IEC60694. This circuit breaker is made with mature  APG technology . The application of VD4terminal buffer guaranteesthe indoorterminal is ever more reliable in nay operation environment. VD4 canfully meet the requirement of GB, DL, IEC, DIN, VDE as well as standards of other advanced industrial countries.

++++Service environment:
     a) Airtemperature: Maximumtemperature: +40℃; Minimumtemperature:-25℃
     b) Humidity: Monthly average humidity 95%; Daily average humidity 90%. 
     c) Altitude above sea level: Maximum installation altitude: 2500m 
     d) Ambient air not apparently polluted by corrosive and flammable gas, vapor etc. 
     e) Nofrequent violent shake
++++ Main technical specifications: