LW8-40.5 outdoor SF6 circuit breaker is an outdoor device used in AC 50HZ three-phase 40.5KV power system, to act as the protecting and control unit for grid equipments and industrial mining enterprises equipments. It is applicable to locations that need frequent operating in rated current or under repeatedly on/off short circuit current. Containing the current transformer for measurement and protection. It can directly replace SW2-35 less oil circuit breaker and various types of oil circuit breaker with transition bracket, also be used as a tie breaker and switching capacitor group situations with CT14 type spring mechanism.  a. The circuit breaker is outdoor small ceramic column structure, which equipped with CT14 spring operation mechanism; mechanism and main part connected with simple installation. It has features of convenient adjustment, reliable operation, suitable for frequent operation; mechanism service life more than 3000 times; b. Adopt air-compression arc-extinguishing structure, with strong breaking capacity, 40kA total breaking times up to 12, which is the highest in China; c. Reliable transformer sealing performance. Adopt import seal; dynamic seal adopts "V" type sealing ring with spring pressure compensation structure; the secondary wiring board matched by cooperative enterprises, to ensure the annual leakage rate less than 1 %; d. Inner current transformer adopts micro crystallizing alloy high magnetic materials, with accurate class up to grade 0.2 or grade 0.2S. According to users' needs, it can be matched with 12 transformers, to meet the load line of 50 km without restrike.1. Ambient air temperature: -5~+40 and the average temperature should not exceed +35 in 24h. 2. Install and use indoors. Altitude above sea level for operation site should not exceed 2000M. 3. Relative humidity should not exceed 50% at max temperature +40. Higher relative humidity is allowed at lower temperature. Ex. 90% at +20. But in view of the temperature change, it is possible that moderate dews will produce casually. 4. Installation gradient not exceed 5. 5. Install in the places without fierce vibration and shock and the sites insufficient to erode the electrical components. 6. Any specific requirement, consult with manufactory.