[2024] All About Circuit Breakers Explained in Detail

  A circuit breaker is a semi-automatic switching device that is used to control and protect the electrical power circuit during abnormal or faulty condition by interrupting the the flow of over-current, short circuit current or fault current. They are designed to open the electrical circuit automatically when high current more than predetermined value flows in the circuit in-order to protect the electrical system from getting damage, prevent the risk of fire, power outage or protect people from the electric shock. 

Working of Circuit Breaker

    Circuit breaker essentially consists of fixed and moving contacts. These contacts are touching each other and carrying the current under normal conditions when the circuit is closed. When the circuit breaker is closed, the current carrying contacts, called the electrodes, engaged each other under the pressure of a spring.

    During the normal operating condition, the arms of the circuit breaker can be opened or closed for a switching and maintenance of the system. To open the circuit breaker, only a pressure is required to be applied to a trigger.

Whenever a fault occurs on any part of the system, the trip coil of the breaker gets energized and the moving contacts are getting apart from each other by some mechanism, thus opening the circuit.

Types of Circuit Breaker

  Circuit breakers are classified on the basis of installation location, operating mechanism rated voltages level and arc quenching medium.

The classification of the circuit breaker on the basis of installation location has been listed below.

1. Indoor Circuit Breaker
2. Outdoor Circuit Breaker

The classification of the circuit breaker on the basis of operating mechanism has been listed below.

1. Spring-operated Circuit Breaker
2. Pneumatic Circuit Breaker
3. Hydraulic Circuit Breaker

The classification of the circuit breaker on the basis of rated voltage level has been listed below.

1. Low voltage Circuit Breaker
2. Medium voltage Circuit Breaker
3. High voltage Circuit Breaker

The classification of the circuit breaker is on the basis of arc quenching medium has been listed below.

1. Air Circuit Breaker
2. Oil Circuit Breaker
3. Sulphur Hexafluoride Circuit Breaker
4. Vacuum Circuit Breaker

Advantages of Circuit Breaker

  Advantages of circuit breaker has been listed below.

1. Can be reused multiple times without replacement
2. More reliable
3. Operated manually or automatically for switching purposes
4. Provide selective protection and isolation of different parts of the power system
5. Interrupt high fault currents without producing harmful gases or flames
6. Reduce the risk of fire hazards and power outages caused by faults

Disadvantages of Circuit breaker

    Disadvantage of using circuit breaker has listed below.

1. High initial and maintenance cost
2. Highly sensitive may result more frequent tripping without any fault
3. Sometimes slower response time which may lead to high damage in the case of fault