RCBO circuit breaker as a big branch of miniature circuit breaker,takes different responsibility of the normal one we recognize.

1.Meaning of RCBO:

The residual current device (RCD) or residual current circuit breaker (RCCB) enables the rapid disconnection of electricity, thereby avoiding prolonged and potentially serious shocks. An RCD device complete with overcurrent protection is called an RCBO, or residual current circuit breaker with overcurrent protection.

The primary functions of RCBOs are to ensure protection against earth fault currents, overload, and short circuit currents. It is recommended that an RCBO be attached to each separate circuit, meaning that a fault in one circuit will not affect the functioning of the others. Such devices allow for disconnection of the circuit for the protection of people and equipment in the event that the current becomes unbalanced. They can be operated exclusively of other overcurrent protective devices within the rated short-circuit capacity.

Design and testing requirements for RCBOs are outlined in the set of standards: IEC/EN 61009: Residual current circuit-breakers with integral overload protection for household and similar uses (RCBO).

2.How does it work:

As previously mentioned, the RCBO ensures protection against two types of electrical fault. The first of these faults is the residual current or earth leakage. This will happen when there is an accidental break in the circuit, which may occur as a result of wiring errors or DIY accidents (such as cutting through a cable when using an electric hedge cutter). If the supply of electricity isn’t broken, then the individual will experience a potentially fatal electric shock.

The other type of electrical fault is the overcurrent, which may take the form of an overload or short circuit. In the first instance, the circuit will be overloaded with too many electrical devices, resulting in the transfer of power exceeding the cable capacity. Short-circuiting may also happen as a result of insufficient circuit resistance and high-level multiplication of the amperage. This is associated with a greater level of risk than overloading.