SUMMARY:

　　The three-phase combined over-voltage protector is a novel over-voltage protection equipment, which is mainly used in the power system below 35KV to protect the electrical equipment such as transformer, switch, bus, motor, parallel compensation capacitor, etc., which can limit the atmospheric over-voltage and the operating over-voltage caused by each vacuum circuit breaker, and the over-voltage relative to ground and phase to phase can cause reliable limiting effect. The three-phase combined over-current protector consists of four lightning arresters, which are connected in four-star mode, so that the over-current of each phase, ground and phase can be protected. Due to the ingenious arrangement of the structure, an over-current protector plays the role of six arresters. At the same time, it overcomes the disadvantage that the simple star connection of three arresters can not protect the phase to phase better. The three combined over-current protectors can be of series phase to phase type or gapless type.

　　Service conditions:

　　1. Suitable for outdoor and indoor use;

　　2. The ambient temperature is - 40 ℃ ~ 40 ℃;

　　3. Altitude not more than 25000m;

　　4. The power frequency is not more than 62Hz, not less than 48Hz;

　　5. Maximum wind speed no more than 35

　　6. Areas with seismic fracture degree of 7 and below;

　　7. The long-term working voltage of the over-current protector shall not exceed the continuous operating voltage.