Why SF6 is used in circuit breaker?

So due to high dielectric strength and high cooling effect, SF6 gas is approximately 100 times more effective arc quenching media than air. Due to these unique properties of this gas, SF6 circuit breaker is used in a complete range of medium voltage and high voltage electrical power system.

What is interrupter in circuit breaker?

In electrical engineering, a vacuum interrupter is a switch which uses electrical contacts in a vacuum. It is the core component of medium-voltage circuit-breakers, generator circuit-breakers, and high-voltage circuit-breakers.

Where are SF6 circuit breakers used?

Developed in the 1950s and onward, SF6 circuit breakers are widely used in electrical grids at transmission voltages up to 800 kV, as generator circuit breakers, and in distribution systems at voltages up to 35 kV.

What is the major drawback of using SF6 circuit breakers?

SF6 breakers are costly due to the reason for the high cost of SF6. The internal parts need cleaning during periodic maintenance under a clean and dry environment. A special facility requires transportation and the maintenance of the quality of gas.

How much pressure is in a SF6 breaker?

Working of SF6 Circuit Breaker In the closed position of the breaker, the contacts remain surrounded by sulphur hexafluoride gas (SF6) gas at a pressure of about 2.8 kg/cm2. When the breaker operates, the moving contact is pulled apart and an arc is struck between the contacts.

Why SF6 is used for high voltage?

For many decades, SF6 has been the go-to dielectric insulating material for high-voltage electrical systems installed in enclosed spaces. The reasons include its high electrical insulating properties, non-flammability, non-toxicity, low maintenance, and competitive cost.

What is the purpose of interrupter?

An interrupter in electrical engineering is a device used to interrupt the flow of a steady direct current for the purpose of converting a steady current into a changing one.

What is the pressure of SF6?

Rated SF6 gas pressure is unified at 0.6 MPa, gauge for all components.

What is difference between SF6 and VCB?

SF6 circuit breakers allow 5,000-20,000 mechanical operations whereas vacuum circuit breakers have 10,000-30,000 mechanical operations possible. SF6 circuit breakers support 10-50 short-circuit operations. This number is higher in the case of vacuum circuit breakers which can allow 30-100 short-circuit operations.

What are the advantages and disadvantage of SF6 circuit breaker?

Advantages and disadvantages of SF6 circuit breakers

  • Advantages of SF6 circuit breakers. It has an enclosed construction. It has unique physical properties. It is stable. It is versatile.
  • Disadvantages of SF6 circuit breakers. It has a high cost. It has to be reconditioned. It needs special protection equipment.

Is SF6 heavier than air?

Clean SF6 gas is an inert, stable, colorless, odorless, nontoxic, nonflammable gas. It is approximately five times heavier than air and will displace air in confined areas. SF6 gas contains no oxygen and will not support life.