Introduction: 
Understanding the various classification methods for Residual Current Circuit Breakers (RCCBs) is essential for electrical safety and compliance. RCCBs, crucial in protecting against electrical hazards, come in different types based on their operation, design, and functionality. This guide delves into the intricate classification of RCCBs, including Residual Current Breakers with Overcurrent protection (RCBOs), to help professionals and enthusiasts alike make informed decisions for their electrical installations. 

Rccb     1.Based on the Mode of Operation:

    • RCBOs (Residual Current Breakers with Overcurrent protection) that operate in relation to the power supply voltage (Electronic type).
      • Cannot automatically disconnect during power supply voltage failure.
      • Can trip in hazardous situations during power supply voltage failure (e.g., due to a ground fault).
    • Note: RCBOs with △n=30mA are tested according to section 9.9.1.5.
  1. Based on the Device Type:
    • Fixed devices and RCBOs with fixed wiring.
  2. Based on the Number of Poles in the Current Circuit:
    • Single-pole RCBOs with one overcurrent protection pole and a non-breakable neutral line.
    • Two-pole RCBOs with one overcurrent protection pole.
    • Two-pole RCBOs with two overcurrent protection poles.
    • Three-pole RCBOs with three overcurrent protection poles.
    • Three-pole RCBOs with three overcurrent protection poles and a non-breakable neutral line.
    • Four-pole RCBOs with three overcurrent protection poles.
    • Four-pole RCBOs with four overcurrent protection poles.
  3. Based on the Adjustability of Residual Current:
    • RCBOs with only one rated residual operating current.
  4. Based on Performance Under Impulse Voltage to Prevent Nuisance Tripping:
    • RCBOs with normal resistance to nuisance tripping.
  5. Based on Performance with DC Components:
    • Divided into: a) Type AC RCBO; b) Type A RCBO.
  6. Based on Delay Time When Residual Current Occurs:
    • Instantaneous RCBOs: General-purpose type.
    • Delayed RCBOs: Selective type S.
  7. Based on Protection Against External Influences:
    • Enclosed RCBOs (do not require a proper casing).
  8. Based on Mounting Method:
    • Surface-mounted RCBOs.
  9. Based on Wiring Method:
    • RCBOs related to electrical connections and mechanical installation.
  10. Based on Instantaneous Trip Current:
    • Type C: 5In~10In
    • Type D: 10In~20In
  11. Type of Terminal Connections:
    • RCBOs with threaded terminal connections for external copper conductors.

Conclusion:
In conclusion, the classification of Residual Current Circuit Breakers (RCCBs) encompasses a wide range of types and specifications, each designed to meet specific safety standards and application requirements. From the mode of operation to the type of device and adjustability of residual current, understanding these classifications is key to selecting the right RCCB for your needs. Whether for residential, commercial, or industrial use, ensuring your installations are equipped with the appropriate RCCB type is a critical step towards enhancing electrical safety and preventing potential hazards.