Distinguishing Type A, AC, and B Residual Current Circuit Breakers (RCCBs)


Type AC RCCBs:

  • Specifically designed for linear loads like incandescent lamps, electric heaters, water heaters, ovens, and vacuum cleaners.
  • Primarily detect sinusoidal residual AC currents, disconnecting the circuit when this residual current exceeds a predetermined threshold.
  • Generally not suitable for loads with a DC component or pulsating DC loads.

Type A RCCBs:

  • Capable of detecting not only sinusoidal residual AC currents but also residual currents with a DC component, such as pulsating DC.
  • Ideal for rectified loads, including induction cookers, microwaves, dishwashers, and settings with a high use of electronic devices like home appliances, office equipment, and computers.
  • Provide more comprehensive protection as they can handle a wider range of leakage scenarios.

Type B RCCBs:

  • Designed to offer advanced protection, particularly in environments with smooth DC components.
  • Detect sinusoidal residual AC currents, pulsating DC currents, and smooth DC currents.
  • Especially suitable for applications like electric vehicle charging stations, solar power systems, and other scenarios involving DC power sources.


The primary differences between Type A, AC, and B RCCBs lie in their sensitivity and adaptability to various types of residual currents. The choice of RCCB depends on the characteristics of the circuit to be protected and the desired level of safety. In some cases, it may be necessary to use a combination of different types of RCCBs to ensure comprehensive protection. Understanding these distinctions is crucial for selecting the right RCCB to meet specific safety requirements and adapt to the electrical characteristics of different environments.