Double Pressure SF6 Circuit Breaker
In Double pressure SF6 circuit breakers the gas is stored at two different pressure levels: high pressure (around 20 bar) and low pressure (around 3-4 bar). This design provides better control over the release of SF6 gas during circuit breaker operation.
Construction of Double Pressure SF6 Circuit Breaker
- The double pressure puffer type SF6 circuit breaker is more advanced design.
- It includes two pressure chambers a high-pressure chamber and a low-pressure chamber.
- The fixed and moving contacts are placed inside the high-pressure chamber.
- An operating mechanism is used to open and close the contacts.
- A valve controls the flow of SF6 gas between the two chambers.
Working of Double Pressure SF6 Circuit Breaker
- During normal operation the high-pressure chamber contains the SF6 gas and the contacts are closed.
- When a fault occurs the operating mechanism opens the contacts and the valve allows a controlled amount of SF6 gas to flow from the high pressure chamber to the low pressure chamber.
- When the gas flows into the low pressure chamber it undergoes expansion. which cools the gas and generates a high velocity flow.
- The expanding and cooling SF6 gas extinguishes the arc by rapidly quenching it.
- The contacts are fully opened interrupting the current flow.
SF6 Circuit Breaker – Types, Construction, Working and Applications
Sf6 circuit breakers are used for their high interrupt capacity, compact design, and reliable performance these are important factors for modern electrical power systems especially in high voltage applications also SF6 gas is a potent greenhouse gas and is being made to reduce its usage and improve its environmental impact. In this article, we will study about SF6 Circuit Breaker and its functioning in detail.