RCDs are designed for protection against electrocution or electrical fires. This is done by automatically cutting off the supply of electricity when an electric current leakage is sensed in a circuit. There are some significant distinctions between RCDs and RCBOs. The RCBOs are integrated with an electronic switch and designed for the transfer and breakage of currents under normal service conditions for the opening of contacts when the residual current is of a certain level under defined conditions. These devices are also constructed for protection against overload and short-circuit currents. 

The RCBO will break the circuit if the current demand surpasses a specific level. An overload may be sensed in the event of a short circuit, or unwarranted demand due to the connection of multiple devices. This will inevitably cause the circuit to break. There would be a substantial risk of the wires melting and catching fire if the circuit wasn’t broken. The RCBO thus offers safety and protection for people, equipment, and property.     

The RCCB has a very comparable functionality to the RCBO. However, it doesn’t deliver integral overcurrent protection and so doesn’t protect against overloading or short-circuiting. Instead, the RCCB provides exclusive earth leakage protection and necessitates the fitting of an external circuit breaker for the assurance of overload and short circuit protection. 

The MCB, or miniature circuit breaker, is an electrical switch incorporated for the protection against overcurrent in an electrical circuit. It automatically stops the flow of electricity through the circuit upon detection of a fault. These circuit breakers can be switched on or off for circuit isolation and they are quite safe to use with the conductor contained within plastic casing. The main difference between an RCBO and MCB is that the MCB doesn’t provide protection against earth leakage. 

The replacement must be carried out in accordance with the manufacturer’s instruction and guidelines as per standard. The levels of resistance and insulation tests will be required to check, thereby confirming that the RCBO insulation levels correspond with the required specification. 

It must be ensured that the power supply is disconnected before proceeding with the wiring of an RCBO. A PE (Polyethylene) cable should then be connected to the earth bar, with the power cables being connected to the top of the isolator. The phase cable should be positioned to the left of the terminal, along with the neutral cable to the right. The busbar of appropriate length must be cut before connection to the bottom of the isolator and RCBO.  

A neutral cable should be connected from the bottom of the isolator to the earth bar. The outbound cables will be the twin core and earth. Earth sleeving should be used to cover the earth wires before connection to the earth bar. It will then be necessary to attach the brown live wire and the neutral blue wire to their respective terminals. Wiring should be cut to the suitable length, with the earth lead being connected to the corresponding bar. This procedure should continue with the connection of the neutral supply leading to the relevant bar. 

IPD offers ABB’s RCBO, a compact solution for complete protection with a rated residual current sensitivity I?n range from 10mA to 30mA.  

IPD offers ABB’s RCBO (Residual Current Circuit Breaker with over-current protection) switch, a range designed to ensure flexibility with uncompromising safety and are compliant to worldwide product standards (AS/NZS 61009-1 Ann. G; AS/NZS 61009-2-1), warranting reliability and safety for people and assets. This standard applies to residual current operated circuit breakers with integral overcurrent protection functionally independent of, or functionally dependent on, line voltage for household and similar uses, for rated voltages not exceeding 440 V AC with rated frequencies of 50 Hz, 60 Hz or 50/60 Hz and rated currents not exceeding 125 A and rated short circuit capacities not exceeding 25 kA for operation at 50 Hz or 60 Hz.