How does SF6 circuit breaker work?
In an SF6 Circuit breaker, sulphur hexafluoride gas is used as the arc quenching medium. The contacts of the breaker are opened in a high-pressure flow sulphur hexafluoride (SF6) gas and an arc is struck between them. The gas captures the conducting free electrons in the arc to form relatively immobile negative ions.
What is an SF6 switch?
Load Break & Fault Interrupting Switch SF6 gas provides excellent electrical and mechanical properties and offers many advantages compared to other dielectrics. Switches can be operated either manually or through various distribution automation packages.
Why do we use SF6 in circuit breakers?
SF6 CIRCUIT BREAKER SF6 circuit breakers are also used mainly in medium voltage applications. In this breaker SF6 gas is used for arc quenching due to its ability of quenching the arc very efficiently.
What is SF6 gas insulated switchgear?
S SF6 gas insulated switchgear is a new generation medium voltage switchgear. The entire SF6 gas tank sealed high-voltage components such as busbars, circuit breakers, disconnectors with 1.4bar pressure SF6 gas in IP67 protection degree.
Is SF6 toxic?
Sulfur hexafluoride (SF6) is a relatively nontoxic gas used in a number of applications for its inert qualities. While SF6 is inert during normal use, when electrical discharges occur within SF6-filled equipment, toxic byproducts can be produced that pose a threat to health of workers who come into contact with them.
What is SF6 used for?
Sulfur hexafluoride (SF6) /is/ used as an electrical insulating material in circuit breakers, cables, capacitors, and transformers .
Where is SF6 used?
SF6 gas is extremely chemically stable, non-flammable and highly electronegative, with an excellent dielectric property of approximately 2.5 times more than air. Therefore, it is commonly used in electrical switchgear, transformers and substations as an electrical insulation, arc quenching and cooling medium.
What is the function of gas insulated switchgear?
Gas Insulated Switchgear (GIS) is the name for a unit that houses these components and circuits in a single gas tank with a compact footprint. Grounding devices that prevent electrical shock and lightning arresters that prevent dielectric breakdowns from lightning strikes are also included to enhance safety.
Why is SF6 harmful?
It is a potent greenhouse gas with a high global warming potential, and its concentration in the earth atmosphere is rapidly increasing. During its working cycle, SF6 decomposes under electrical stress, forming toxic byproducts that are a health threat for working personnel in the event of exposure.
Why is SF6 so bad?
While SF6 is regarded as a non-toxic gas, experts agree that it can displace oxygen in the lungs, and therefore cause asphyxia if too much is inhaled.
Is SF6 harmful?
Higher exposures can cause a build-up of fluid in the lungs (pulmonary edema), a medical emergency, with severe shortness of breath. * High exposure can cause headache, confusion, dizziness, suffocation, fainting, seizures and coma. * Sulfur Hexafluoride may damage the liver and kidneys.
How bad is SF6?
Cheap and non-flammable, SF6 is a colourless, odourless, synthetic gas. However, the significant downside to using the gas is that it has the highest global warming potential of any known substance. It is 23,500 times more warming than carbon dioxide (CO2).
Why is it important to use SF6 in switchgear?
SF6 is used as an insulating medium in Switchgear and the SF6 free Switchgear, while having all the same advantages as SF6 based Switchgear, such as compactness, uses environmentally safe insulating mediums. This is the reason behind the massive appeal of SF6 alternatives. Blue GIS offered by Siemens is F-gas free and has a GWP of less than 1.
How is SF6 gas stored in a circuit breaker?
Here SF6 gas was compressed and stored in a high-pressure reservoir. During operation of SF6 circuit breaker, this highly compressed gas is released through the arc in the breaker and collected to a relatively low-pressure reservoir and then it is pumped back to the high-pressure reservoir for reutilizing.
Is the use of SF6 gas going away?
So even though there is a trend towards switching to clean, environmentally friendly switchgear, there is no indication that the use of SF6 gas in switchgear is going to become nonexistent in the imminent future.
What does SF6 mean in a contained environment?
SF6 gas in a contained environment (such as switchgear) does not have any impact on the surroundings. Which means that the concern originates from the leakage of the gas while handling (installation or decommissioning of switchgear) or leakage throughout the operation of the equipment.
