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 larger 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 a Circuit Breaker?

A circuit breaker is a protective device that can break the circuit automatically under fault conditions.
The circuit breaker can make or break the circuit either manually or by remote control.
Remember that the circuit breaker does not work alone which 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 Breakers.
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 the protection of distribution lines.
  2. In the Switchyard oil circuit breaker was 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 breakers, the contacts are immersed in the oil so the oil is used for two purposes one is the extinction of ARc and the other is to provide the insulation between the contacts, therefore there is a huge amount of oil required which increases 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 and not provide insulation between the contacts. To provide insulation solid insulator material is used.

  1. As less oil is required good economic considerations.
  2. As the volume of oil is reduced so the risk of fire is 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 breakers,
  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 is required.
  4. Smaller in size.

Disadvantages of Air Blast Circuit Breaker:

  1. An air compressor is required to create high-pressure air.
  2. Additional maintenance is required due to the presence of an Air compressor.

Applications of Air Circuit Breaker:

  1. In the railway system, air circuit breakers are used.
  2. They are also used for the 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 which is why it is used in circuit breakers 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 absorbs 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 is 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 recondition the gas after operation for use again.

Application of Sulfur hexafluoride(SF6) circuit breaker:

  1. SFCircuit breaker is mainly used in high-voltage transmission lines.
  2. They are also used for the 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 an arc quenching medium. We know that in vacuum space there are no particles so it provides high insulation. In vacuum circuit breakers the ARC is produced by only the ionization of metal vapors of contacts. So the strength of the ARC is very low which is why it extinguishes automatically.


  1. There is no chance of fire.
  2. Compact in size.
  3. As I told you before in this circuit breaker the strength of the produced ARC is very low.
  4. High insulation facility.
  5. Requires little maintenance.
  1. The main disadvantage is the high cost of the vacuum arrangement.
  1. As this type of circuit breaker requires 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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