Application, Advantages and Disadvantages of all types of Circuit Breaker

All types of Circuit Breaker Applications, Advantages, and Disadvantages

The electrical transmission distribution system is getting large and complex day by day. To obtain reliability and continuous power supply there is a need to reduce faults. To overcome faults many switchgear equipments are used. The circuit breaker is very important equipment and it is used in major parts of the protection system. There are many types of circuit breakers. Let's know the Application, Advantages, and Disadvantages of all types of Circuit Breaker.

What is Circuit Breaker?

A circuit breaker is a protective device which can break the circuit automatically under the fault condition.
The circuit breaker can make or break the circuit either manually or by remote control.
Remember that the circuit breaker does not work alone that means it works with Relay. The relay senses the fault and sends the signal to the circuit breaker then the circuit breaker breaks the circuit.

Types of Circuit Breaker:

Classification of the circuit breaker,

types of circuit breaker, classification of circuit breaker

Oil Circuit Breaker

We know that when the circuit breaker breaks the circuit by separating its contacts an ARC is produced. We need to extinguish the ARC because it continues the flow of current even the contacts of the circuit breaker getting separated. In which circuit breakers Oil is used for extinguishing the ARC they are called Oil Circuit Breaker.
Mainly insulating oil or mineral oil(same as transformer oil) is used in the oil circuit breaker.

Applications of Oil Circuit Breaker:

  1. Oil circuit breakers are used in small and medium substations for protection of distribution lines.
  2. In Switchyard oil circuit breaker used.
  1. The oil extinguishes the ARC by creating the hydrogen gas and the hydrogen gas can cool the ARC.
  2. The oil also helps for cooling in the circuit breaker.
  3. The produced hydrogen gas provides good insulation between the contacts.
  1. As oil is used there is a risk of fire.
  2. There is a requirement for periodic oil replacement.

Minimum Oil Circuit Breaker(MOCB)

In bulk oil circuit breaker the contacts of being immersed in the oil so the oil is used for two purposes one is the extinction of ARc and other is to provide the insulation between the contacts, therefore there is a huge amount of oil required which increased the cost. But in the case of the minimum oil circuit breaker(MOCB), a small amount of oil is used which only can extinguish the ARC not provide the insulation between the contacts. To provide insulation solid insulator material is used.

  1. As less oil is required good echonomic consideration.
  2. As the volume of oil is reduced so the risk of fire also reduced.
  3. Smaller in size than the bulk oil circuit breaker.

Air Circuit Breaker

In the air circuit breaker, the air is used as an ARC quenching medium. It is in very simple in construction. Air circuit breakers are used for smaller voltage than other circuit breakers. Because although here no arrangement is needed for extinguishing the ARC if we use it in high voltage the length of the gap between the contacts should be large. 

There are two types of Air Circuit breaker,
  1. Plain air circuit breaker
  2. Air blast circuit breaker

Advantages of Air Blast Circuit Breaker:

  1. As no oil is used there is no risk of fire.
  2. It has the facility of frequent operation.
  3. Less maintenance required.
  4. Smaller in size.

Disadvantages of Air Blast Circuit Breaker:

  1. Air compressor is required to create high-pressure air.
  2. Additional maintainance is required due to presence of Air compressor.

Applications of Air Circuit Breaker:

  1. In the railway system, air circuit breakers are used.
  2. They are also used for protection of small transformers.

Sulfur hexafluoride(SF6) circuit breaker

In this type of Circuit breaker, Sulfur hexafluoride gas is used to extinguish the ARC. As the Sulfur hexafluoride gas has the tendency to absorb free electrons that is why it is used in circuit breaker to absorb produced free ARC electrons. Mainly high-pressure SF6 gas is used.


  1. The time of Arcing is very less as the Sulfur hexafluoride gas quickly absorb the arc electrons.
  2. As the dielectric strength of Sulfur hexafluoride gas is very high so this circuit breaker can interrupt a large amount of current.
  3. There is no risk of fire.
  4. As the whole chamber closed tightly there is no moisture problem.
  5. Low maintenance cost.
  1. As the SF6 gas is very costly there so is an economic disadvantage.
  2. As the SF6 gas is very costly we need to reuse the gas after the operation and we need additional equipment to reconditioned the gas after operation for use again.

Application of Sulfur hexafluoride(SF6) circuit breaker:

  1. SFCircuit breaker mainly used in high voltage transmission line.
  2. They also used for protection of high voltage transformers.

Vacuum circuit breaker

In Vacuum Circuit breakers the contacts are placed in a vacuum or the vacuum is used as arc quenching medium. We in vacuum space there is no particles so it provides high insulation. In vacuum circuit breaker the ARC is produced by only the ionization of metal vapors of contacts. So the strength of the ARC is very low that is why it extinguish automatically.


  1. There is no chance of fire.
  2. Compact in size.
  3. As I told before in this circuit breaker the strength of produced ARC is very low.
  4. High insulation facility.
  5. Required little maintenance.
  1. The main disadvantage is the high cost for the vacuum arrangement.
  1. As this type of circuit breaker required less maintenance so they are used in the rural area transmission line.

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Application, Advantages and Disadvantages of all types of Circuit Breaker Application, Advantages and Disadvantages of all types of Circuit Breaker Reviewed by Author on January 07, 2019 Rating: 5
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