1. There is no gas in ZW32-12 high-voltage vacuum circuit breaker. You may be talking about sulfur hexafluoride circuit breaker, and the gas in it is non-toxic.

2. Sulfur hexafluoride circuit breaker is an oil-free switchgear using SF6 gas as insulation medium and arcing: A. The insulation performance and arcing characteristics of sulfur hexafluoride circuit breaker are much higher than those of oil circuit breaker. Because of its high price and high requirements for the application, management and operation of SF6 gas, it is not widely used in medium voltage (35, 10KV).

B SF6 gas is 5.135 times heavier than air, and its boiling point is -60℃ at one atmospheric pressure. When the temperature is below 150℃, SF6 has good chemical inertness and does not react with metals, plastics and other materials commonly used in circuit breakers. When it is decomposed into various components at high temperature caused by high-power arc, it will be recombined in a very short time after the arc is extinguished. There is no carbon element and air in SF6, which can avoid contact oxidation.

C, SF6 dielectric strength is very high, and increases with the increase of pressure. At 1 atmosphere, the dielectric strength of SF6 is about 2 ~ 3 times that of air. When the absolute pressure is 3 atmospheres, the dielectric strength of SF6 can reach or exceed that of commonly used insulating oil. SF6 has good arc extinguishing performance. In a simple interrupter, its arc extinguishing ability is 100 times greater than that of air. In SF6, when the arc current is close to zero, there is a high temperature only at the center of the arc column with a small diameter, and the surrounding is a non-conductive layer. In this way, the dielectric strength of the arc gap will recover quickly after the current crosses zero.

3. Most of the high-voltage circuit breakers used now are vacuum circuit breakers, and SF6 circuit breakers are rarely used now and will soon be eliminated.