When you're having a new fuse board installed in your Kent home, one of the key decisions is whether to go for an RCD consumer unit or a full RCBO consumer unit. Both provide essential electrical protection, but they work differently — and the choice can affect your daily life in ways you might not expect.
As NAPIT registered electricians who install fuse boards across Kent every week, L Fowler Electrical gets asked this question constantly. Here's our honest, practical guide to the difference between RCDs and RCBOs — and which type of consumer unit we recommend for most Kent homes.
What Is an RCD?
An RCD (Residual Current Device) is a safety device that detects earth faults — situations where electricity is leaking to earth, potentially through a person. When an RCD detects a fault, it cuts power in milliseconds — fast enough to prevent electrocution.
In a traditional RCD consumer unit (sometimes called a split-load consumer unit), one or two RCDs protect groups of circuits. For example, one RCD might protect all your upstairs circuits, and another might protect all your downstairs circuits.
The problem with this arrangement is that if a fault develops on one circuit — say, a faulty appliance in the kitchen — the RCD protecting that group trips, cutting power to all the circuits in that group. You might lose power to your kitchen, living room and dining room simultaneously, even though only one circuit has a fault.
What Is an RCBO?
An RCBO (Residual Current Breaker with Overcurrent) combines the functions of an RCD and an MCB (Miniature Circuit Breaker) in a single device. Each RCBO protects one individual circuit — providing both earth fault protection and overcurrent protection in one unit.
In a full RCBO consumer unit, every circuit has its own RCBO. If a fault develops on one circuit, only that circuit trips. The rest of your home is completely unaffected. You can identify the faulty circuit immediately from the consumer unit, reset it once the fault is resolved, and carry on.
RCD vs RCBO — The Key Differences
Fault Isolation
This is the biggest practical difference. With an RCD consumer unit, a fault on one circuit can trip multiple circuits. With a full RCBO consumer unit, only the faulty circuit trips. For Kent homeowners, this means the difference between losing power to one socket and losing power to half your house.
Cost
Full RCBO consumer units cost more than RCD consumer units — typically £50–£150 more for the unit itself, plus slightly more installation time. However, the additional cost is modest compared to the total installation price, and the benefits in terms of convenience and fault isolation are significant.
Compliance
Both RCD and RCBO consumer units comply with BS 7671 18th Edition wiring regulations, provided they use metal enclosures. However, the 18th Edition Amendment 2 (2022) places greater emphasis on individual circuit protection, and full RCBO consumer units are increasingly the preferred choice for new installations.
Nuisance Tripping
With an RCD consumer unit, a nuisance trip on one circuit (caused by a faulty appliance, for example) can affect multiple circuits. With a full RCBO consumer unit, nuisance tripping is isolated to the affected circuit. This is particularly important for Kent homeowners with home offices, medical equipment, or other critical loads.
Which Type of Consumer Unit Do We Recommend?
For the vast majority of Kent homes, we recommend a full RCBO consumer unit. The additional cost is modest, the benefits are significant, and it's the type of consumer unit we'd want in our own homes.
The only situation where we might recommend an RCD consumer unit is where budget is a significant constraint and the property has a small number of circuits. Even then, we'd discuss the trade-offs honestly and let you make an informed decision.
For new builds, extensions and major renovations in Kent, a full RCBO consumer unit is always our recommendation. It future-proofs your installation, provides the best possible protection, and makes fault-finding straightforward.
What About Surge Protection?
The 18th Edition wiring regulations now recommend the installation of a Surge Protection Device (SPD) alongside your consumer unit. An SPD protects your appliances and electronics from voltage spikes caused by lightning strikes, grid switching and other power disturbances.
L Fowler Electrical can integrate an SPD with your new consumer unit installation across Kent. We'll advise on whether an SPD is recommended for your specific property and location — coastal Kent properties, for example, can be more susceptible to lightning-related surges.
Consumer Unit Brands We Install in Kent
L Fowler Electrical installs quality consumer units from leading manufacturers including:
- Hager — German-engineered, excellent build quality, widely used in domestic and commercial installations across Kent
- Schneider Electric — French manufacturer with a strong reputation for reliability and a comprehensive range of consumer units
- Wylex — British brand with a long history in the UK market, good value and reliable performance
- Eaton MEM — High-quality units with excellent MCB and RCBO performance, popular for commercial installations
We'll recommend the best brand and model for your specific property and budget. All units we install are compliant with BS 7671 18th Edition and carry the appropriate CE/UKCA markings.
Getting a Quote for Your Kent Fuse Board
L Fowler Electrical provides free, no-obligation quotes for fuse board installations across Kent. We cover Deal, Dover, Canterbury, Sandwich, Margate, Ramsgate, Broadstairs, Folkestone, Faversham, Whitstable, Herne Bay, Hythe, Ashford, Sittingbourne, Whitfield, Eythorne, Aylesham, Wingham, Tilmanstone and Walmer.
Call us on 07966 182979 or use our contact form to arrange a free survey. We'll assess your property, advise on the best consumer unit for your needs, and provide a transparent, itemised quote with no hidden costs.
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Get a free survey and quote for fuse board installation anywhere in Kent. We'll recommend the best consumer unit for your property and budget.