SF6 Circuit Breaker

In the SF6 circuit breaker the current carrying contacts operate in sulphur hexafluoride gas is known as an SF6 circuit breaker. It is an excellent insulating property and high electro-negativity. It can be understood that, high affinity of absorbing free electron. The negative ion is formed when a free electron collides with the SF6 gas molecule; it is absorbed by that gas molecule. The two different ways of attachment of electron with SF6 gas molecules are

The negative ions which are formed will be much heavier than a free electron. Therefore, when compared with other common gases overall mobility of the charged particle in the SF6 gas is much less. The mobility of charged particles is majorly responsible for conducting current through a gas. Hence, for heavier and less mobile charged particles in SF6 gas, it acquires very high dielectric strength. This gas good heat transfer property because of low gaseous viscosity. SF6 is 100 times more effective in arc quenching media than air circuit breaker. It is used for both medium and high voltage electrical power system from 33KV to 800KV.

Types of SF6 Circuit Breaker

Single interrupter SF6 circuit breaker applied up to 220

Two interrupter SF6 circuit breaker applied up to 400

 Four interrupter SF6 circuit breaker applied up to 715V