ZW7-40.5 Type vacuum circuit breaker is mainly used for outdoor 35kV power transmission system control and protection also applies to urban and rural power distribution networks and industrial and mining enterprises in the normal operation and short circuit protection purposes. The overall structure of the insulator pillar product type; built vacuum interrupter type on the vase, porcelain vase for the next pillar vase. For frequent operation place. And has good sealing, anti-aging, high pressure, no burning, no explosion, long life, convenient installation and maintenance features. 1. Vacuum arc extinguishing, strong breaking capacity, long electrical life and 10,000 mechanical life; 2. Simple structure, maintenance-free, long maintenance period; 3. Good insulation performance and strong anti-pollution ability; 4. It can be equipped with spring or electromagnetic operating mechanism, with reliable mechanical performance and frequent operation; no fire and explosion hazard; 5. Built-in current transformer, the lecturer's precision reaches 0.2, which can realize three-phase interactive protection; 6. With condensation controller, it can keep the circuit breaker running reliably under certain temperature and humidity.1. Ambient air temperature: -5~+40 and the average temperature should not exceed +35 in 24h. 2. 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.