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Function of circuit breaker: Different types of circuit breakers

It is an automatic switching off device
It offers quick and reliable protection to the power system under fault conditions

Different types of circuit breakers :
  • SF6 circuit breakers
  • Air blast circuit breakers
  • Vacuum circuit breakers
  • Bulk oil circuit breakers
  • Minimum oil circuit breakers

Advantages of SF6 circuit breaker

SF6 breakers gradually replacing the conventional oil & air blast circuit breakers especially at voltage rating 132KV and above due to its following merits
(a) The closed circuit gas cycle coupled with low gas velocity gives noise less operation
(b) Outstanding arc extinguishing properties result in very short arcing times and hence less contact erosion
(c) Drastically reduction in electrical clearances due to its excellent insulating properties
(d) As totally enclosed and sealed from atmosphere, practically suitable for use in coal mines or in any such environments where explosion fire hazards exist

Vacuum circuit breakers

  • Vacuum is used as quenching medium
  • The interrupters are housed in vacuum jar VCB
  • At present, used only up to  22KV voltage class due to its limitations of vacuum interrupters
  • Vacuum bottle is hermetically sealed

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