SF6 Circuit Breaker
A circuit breaker in which the current carrying contacts operate in sulphur hexafluoride or SF6 gas is known as an SF6 circuit breaker.
SF6 has excellent insulating property. SF6 has high electro-negativity. That means it has high affinity of absorbing free electron. Whenever a free electron collides with the SF6 gas molecule, it is absorbed by that gas molecule and forms a negative ion.
The attachment of electron with SF6 gas molecules may occur in two different ways,
These negative ions obviously much heavier than a free electron and therefore over all mobility of the charged particle in the SF6 gas is much less as compared other common gases. We know that mobility of charged particle is majorly responsible for conducting current through a gas.