Puffer action in SF6 Circuit Breaker

                                           
Sf6 is a air circuit breaker since sf6 gas is used in it for extinguishing the arc.
The quenching of arc in SF6 circuit breaker takes place due to the puffer phenomenon taking place inside this circuit breaker

PUFFER PHENOMENON:-

Puffer means quick & short blast of gas on the arc

In SF6 c.b blast os SF6 gas is made on the arc throgh puffer action & the arc gets quenched

As shown in fig above,the fixed & moving contacts are kept in insulating nozzle section.The whole assembley i.e insulating nozzle,puffer action cylinder with moving contact ,a fixed piston is provided to it through the other end of moving contact.The chamber is filled with SF6 gas. Under normal working condition,the contacts are closed but on the of the fault the contacts open so moving contacts move right & SF6 gas move left side.

An arc is struck b/w the moving contact & fixed contact. The travel of movable cylinder causes increase in pressure on sf6 gas & this high pressure SF6 gas travels towards arc i.e it puffs over the arc or in simple we can say it blast over the arc

so when this puffer action is completed the arc gets extinquihed.
This type of c.b is called simple SF6 c.b. but it has limitation of  refilling the SF6 which is has by disconnecting  from its circuit for this we introduced Double pressure dead type SF6.
i will discuss this in next blog definetaly!!!!!