What is RCBO? 

An RCBO is known as a residual current circuit breaker with overcurrent. And this is a type of low-voltage circuit breaker. Basically it is used to protect against earth leakage fault current along with over current. RCBO has additional protection against overload and over current. RCBO is mainly used in microcontrollers and can also be called as a combination of MCCB and RCCB. It is more useful than RRCB, as RCCB does not provide protection against over current. Some RCBOs also have indicators to indicate any earth fault.