Why RCBO Is Better Than RCD in Modern UK Consumer Units
Understanding the Difference Between RCD and RCBO
When upgrading a consumer unit, one of the most common questions is whether RCBO protection
is better than traditional RCD protection. In short — yes, in most modern UK installations,
RCBOs are considered the superior option.
An RCD (Residual Current Device) protects against electric shock by detecting earth leakage.
An RCBO (Residual Current Breaker with Overcurrent protection) combines RCD protection
with MCB (Miniature Circuit Breaker) functionality in one device.
A qualified Electrician in London
will typically recommend RCBO protection for new consumer unit installations.
How an RCD Works
An RCD monitors the balance between live and neutral currents. If it detects an imbalance —
meaning electricity may be leaking to earth — it trips and cuts power.
In older split-load consumer units, one RCD may protect multiple circuits.
The issue? If one circuit develops a fault, the RCD will trip and shut down
all circuits connected to it.
How an RCBO Works
An RCBO performs two functions:
- Protects against earth leakage (like an RCD)
- Protects against overload and short circuit (like an MCB)
Crucially, each RCBO protects a single circuit individually.
If a fault occurs, only that circuit trips — not half the house.
Key Advantages of RCBO Over RCD
- Individual circuit protection – Faults are isolated.
- Reduced nuisance tripping – One faulty appliance won’t cut power to multiple rooms.
- Improved safety discrimination – Easier fault identification.
- Better reliability – Particularly in modern homes with high electrical demand.
Many professional London Electricians
now install fully populated RCBO consumer units as standard practice.
Improved Safety and Fault Isolation
With RCD split-load boards, a single earth fault could trip lighting and socket circuits together.
This can leave parts of a property in darkness — potentially unsafe.
RCBOs isolate faults to the affected circuit only.
This improved discrimination enhances both convenience and safety.
Compliance with UK Wiring Regulations
The 18th Edition of BS 7671 encourages improved circuit separation and fault protection.
While RCD boards are still permitted, RCBO installations align more closely with
modern best-practice recommendations.
During London Landlord EICR Certificates,
installations with RCBO protection often show improved circuit management and fewer widespread issues.
When Might an RCD Still Be Used?
RCD split-load boards may still be used in budget installations or minor upgrades.
However, for full consumer unit replacements, RCBO boards are widely preferred.
In emergency fault situations, isolating a single circuit quickly can be critical —
which is why London Emergency Electricians
often recommend RCBO upgrades where appropriate.
Final Verdict: Is RCBO Better Than RCD?
Yes — in most modern UK properties, RCBO protection is better than traditional RCD split-load systems.
It offers superior fault isolation, improved safety and reduced inconvenience.
If you are upgrading your consumer unit, choosing RCBO configuration is generally
the smarter long-term investment.