RCD vs RCBO – What’s the Difference?
RCD vs RCBO – What’s the Difference?
If you are upgrading your fuse box or reviewing an electrical report, you may have come across the terms RCD and RCBO. While they sound similar, they perform slightly different functions within a consumer unit.
Understanding the difference helps you make informed decisions about electrical protection in your property.
If you are considering an upgrade, you can find more information about our Consumer Unit & Fuse Box Upgrade services in Altrincham.
What Is an RCD?
RCD stands for Residual Current Device.
An RCD is designed to disconnect power quickly if it detects an imbalance in current — typically caused by electricity flowing through a person to earth.
In simple terms, an RCD helps protect against electric shock.
Traditional consumer units often use one or two shared RCDs to protect multiple circuits.
What Is an RCBO?
RCBO stands for Residual Current Breaker with Overcurrent protection.
An RCBO combines:
- Residual current protection (like an RCD)
- Overcurrent protection (like an MCB)
This means each individual circuit has its own combined protective device.
How Do They Differ in Practice?
- RCD Boards: One RCD may protect several circuits. If one circuit develops a fault, multiple circuits can lose power.
- RCBO Boards: Each circuit trips independently. A fault on one circuit does not affect others.
RCBO boards provide better fault discrimination and reduce inconvenience.
Which Offers Better Protection?
Both RCDs and RCBOs provide protection against electric shock.
However, RCBO consumer units are often considered superior because:
- They isolate faults to a single circuit
- They reduce nuisance tripping
- They improve reliability
- They simplify fault finding
Are RCBOs Required by UK Regulations?
Current BS 7671 Wiring Regulations require appropriate RCD protection for most circuits.
While the regulations do not specifically mandate RCBOs in every installation, they are increasingly regarded as best practice for modern domestic properties.
When Is an RCBO Board Recommended?
An RCBO consumer unit is particularly beneficial if:
- You work from home and require stable power
- You have an EV charger installed
- You have sensitive equipment
- You want improved fault isolation
Is an RCBO Board More Expensive?
Yes, RCBO boards typically cost more because each circuit has its own combined protective device.
However, many homeowners consider the improved reliability and protection worthwhile.
Which Should You Choose?
The right option depends on:
- The age of your installation
- Your electrical load
- Your budget
- Whether you are future-proofing the property
A professional inspection will determine the most appropriate configuration.
Need Advice on Consumer Unit Upgrades?
If you are unsure whether an RCD or RCBO board is suitable for your property, we provide professional Consumer Unit & Fuse Box Upgrades in Altrincham with full testing and certification.