What is an RCBO and how does it work?

An RCBO is the abbreviated term for a Residual Current Breaker with Over-Current. An RCBO protects electrical equipment from two types of faults; residual current and over current.

Residual current, or Earth leakage as it can sometimes be referred to, is when there is a break in the circuit that could be caused by faulty electrical wiring or if the wire is accidentally cut. To prevent the current redirecting and causing an electrical shock, the RCBO current breaker stops this.

Over-Current is when there is an overload caused by too many devices being connected or there is a short circuit in the system.

RCBOs are used as a safety measure to reduce to chances of injury and danger to human life and is part of existing electrical regulations that require electrical circuits to be protected from residual current. This generally means that in domestic properties, an RCD will be used to achieve this rather than an RCBO as they are more cost effective however if an RCD trips, it cuts power to all the other circuits whereas an RCBO does the job of both an RCD and MCB and ensures that power continues to flow to all other circuits that haven’t tripped. This makes them invaluable to businesses that simply cannot afford for the entire power system to cut out simply because someone has overloaded a a plug socket (for example).

RCBOs are designed to ensure the safe operation of electrical circuits, triggering disconnections quickly when there is a residual current or over-current detected.

Find out more

At HF Group, with the range of Electrical, Fire & Security, Telecommunications and Control Systems work that we do, RCBOs are frequently used in our work to ensure that UK electrical regulations are met.

To find out more about RCBOs and the work we do Nationwide, please contact us.