What is the difference between Type B, C and D miniature circuit breakers?

When is each type used?

  • Basically, the type refers to the current range at which the circuit breaker trips instantaneously. When selecting the type of circuit breaker, it is important to consider the maximum current that can be expected during normal operation, which most of the time is during equipment startup. In other words, the type of circuit breaker must be selected so that it allows the inrush current without tripping, but not higher currents. You can find another post such as Can someone help me understand Type C MCB that I think you will also find helpful. 

    Type B Circuit Breakers

    Minimum trip current: 3 to 5 times rated current.

    This type of circuit breaker is used for purely resistive loads, or loads with a very small inductive component.

    • Lighting circuits (non-inductive)
    • General purpose outlets

    Type C Circuit Breakers

    Minimum trip current: 5 to 10 times rated current.

    This type of circuit breakers is used for loads with a moderate inductive component, typically electrical equipment which uses low-HP motors or specific types of lighting:

    • Air conditioners
    • Residential / Commercial Pumps
    • Fans
    • Lighting which uses ballasts with an inductive component

    Type D Circuit breakers

    Minimum trip current: 10 to 20 times rated current.

    This type of circuit breaker is used for loads with a very high inductive component, typically found in industrial settings:

    • Large induction motors or transformers
    • X-ray equipment
    • Welding equipment

    Other Relevant articles for Electric Circuit Breakers and their Types

    Example Product

    Type B- Minimum trip current would be 45 - 75 Amps 


    Type C - Minimum trip current would be 75 - 150 Amps


    Type D - Minimum trip current would be 150 - 300 Amps


  • Registered Users Member
    I have fitted an electric shower but the 16A breaker keeps trippung on the high setting.it doesnt trip when the shower is on a low setting.can i put in a breaker with a higher rating.like type c 35A
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