How to choose a circuit breaker?

Circuit breakers are meant to protect an electric circuit from damage resulting from the excess flow of current or overloading of the circuit. Whenever an electrical circuit is detected with faults, circuit breakers ensure protection by interrupting the flow of current.

The majority of circuit breakers are similar when it comes to their operation, but they can be remarkably different depending upon a variety of factors such as voltage class and current rating.

Types of circuit breakers:

Based on structural features, voltage class, and interruption type, circuit breakers are broadly classified into the following types:

a) Solid state

b) Magnetic

c) Low voltage

d) Thermal magnetic

·        Low Voltage Circuit Breakers: These circuit breakers are widely used in residential, industrial and commercial applications. Low voltage circuit breakers include the following:

Miniature circuit breaker (MCB) -  Miniature circuit breakers have non-adjustable trip characteristics, and their rated current is within 100A.

Moulded Case Circuit Breaker (MCCB)- Moulded case circuit breakers have a rate current limit up to 2,500 A. They have a thermal/magnetic operation and it is possible to adjust trip current in more substantial ratings.

Low voltage power circuit breakers are usually mounted on switchgear cabinets.

·        Solid State Circuit Breakers- Solid state circuit breakers are popularly known as digital circuit breakers. These circuit breakers are far more superior than mechanical circuit breakers. They are capable of cutting the circuit in milliseconds and can monitor circuit loads better.

·        Magnetic Circuit Breakers - Magnetic circuit breakers employ solenoid to increase the pulling force with a corresponding increase in the current. Some circuit breaker design does use electromagnetic pulses beside solenoid to break the circuit. These are the most popular circuit breakers.

·        Thermal Magnetic Circuit Breakers - Thermal magnetic circuit breakers are widely used in distribution boards.