RCD And RCBO: What Is The Difference?

RCD and RCBO: What is the difference?

RCD (residual current operated device) and RCBO (residual current operated circuit breaker with overload protection) are both devices used for electrical safety protection. The main differences are as follows:

• Different functions:

RCD: The main function is to detect residual current, that is, when unexpected grounding current appears in the circuit, the circuit is quickly cut off to protect personnel from electric shock. It focuses on leakage protection and does not have overload and short-circuit protection functions.
RCBO: In addition to the leakage protection function of RCD, it also has overload protection function, which can detect and cut off the situation of exceeding the rated current due to excessive load. Some models can also provide short-circuit protection, which can deal with leakage and overload problems at the same time, and the protection is more comprehensive.

• Different tripping sensitivity:

RCD: Usually more sensitive to residual current, the tripping current is generally between 10-30 mA, and it can act quickly when a small leakage current appears, effectively ensuring personal safety.
RCBO: It can also provide residual current protection, but its sensitivity is slightly lower than that of RCD, and the tripping current is usually between 30-300 mA, depending on the model and application scenario.

• Different installation methods and locations:

RCD: It is generally installed at the main distribution board or the power supply line of the electrical device, and is used to provide leakage protection for multiple circuits or a group of circuits.
RCBO: It integrates the residual current protection device and the circuit breaker function in a compact unit. It is usually installed at each branch circuit in the distribution board to provide protection for specific circuits or loads.

• Different application scenarios:

RCD: It is often used in situations where only leakage protection is required, such as outdoor circuits, protection of equipment sensitive to leakage, etc. It can also be used in conjunction with miniature circuit breakers (MCBs) to provide more comprehensive protection for circuits.
RCBO: It is suitable for scenarios with high requirements for circuit protection and the need to prevent leakage and overload faults at the same time, such as branch circuits in household distribution boxes, and circuits with strict electrical safety requirements in commercial and industrial places.