Consumer Units
Also known as a fuse board or electrical fusebox, a consumer unit distributes electricity from the mains supply to individual circuits around a property. It is vital to have a modern, standards-compliant unit, fitted correctly.
Consumer Units Explained
What is a Consumer Unit?
A consumer unit (also known as a fusebox, distribution board or fuse board) distributes electricity from the mains supply to individual circuits around a property.
It acts as the control centre for the power supply while helping to prevent electrical shocks and fires, as each circuit is monitored and will trip the system if any overloads are detected.
How does it work?
It typically includes a main switch which can be used to manually turn the power off and on if required to isolate the supply. Various devices are then fitted according to the requirements of the building and the occupants.
Understanding the terms
Hover over the orange dots on the photo to see tooltip explanations of the key features.
Neatly-installed cables prevent undue strain on conductors
Metal case for fire safety
Earth Bar
RCBO Circuit Breakers offer greater protection
Surge Protection Device
“My main problem was the fuse box constantly tripping and cutting power to several circuits at once. Paul recommended upgrading to a modern RCBO consumer unit, which has been the perfect solution — now each circuit is individually protected. This has made a huge difference, especially as I work from home and can’t afford interruptions to my computer equipment.”
Artemis Anderson, North Devon
The Heart of Your Electrical Installation
Why is the Consumer Unit the heart of your electrics? A modern one does three critical jobs:
1. Distributes power to every home circuit
Lights, sockets, cooker, shower — branches out from the fusebox. It ensures electricity flows where it’s needed without overloading cables.
2. Improved Reliability & Convenience
Unlike outdated Dual RCD units or fuse boxes, an RCBO board prevents unnecessary disruptions by isolating faults to a single circuit rather than cutting power to half your home. This means fewer trips to reset your electrics and better day-to-day reliability.
3. Future-proof & add value to your home
With rising electrical demands from EV chargers, solar, battery storage, and smart home technology, a modern consumer unit ensures your electrical system is ready for the future. Upgrading also adds value to your home and improves energy efficiency.
“Our old fusebox needed replacing and bringing up to modern standards as we had new rooms added and growing needs in the household. We also wanted a way to completely shut down non-essential electrical circuits overnight, saving energy and reducing the amount of electrical interference as we sleep. Paul and the PD Electrical team listened carefully and provided a great solution – a “kill switch” that could give a late-night closedown, whilst keeping essential circuits separated and active overnight.”
Zoë Browning, Ilfracombe
Why Upgrade? 3 Key Reasons
1. Enhanced Safety & Compliance
Modern RCBO consumer units provide individual circuit protection, reducing the risk of electric shocks, electrical fires, and complete power loss to multiple circuits. They also ensure your installation meets the latest 18th Edition Wiring Regulations (BS 7671).
2. Protects against danger
Today’s consumer units include protection that guard against electric shock, overloads, overvoltage and fires. This means the fusebox is constantly monitoring the system, ready to cut power in milliseconds if a fault occurs.
3. Flexibility for the future
New shower, EV charger, solar panels, more sockets? The fusebox is where that starts. A well-designed board has spare capacity for simple, safe, and compliant projects. Fridges/freezers, routers, outdoor electrics and home offices have their own circuits for maximum reliability and convenience.
Dual RCB or RCBO?
Understanding the Difference
At PD Electrical Services (SW) Ltd, we prioritize safety, reliability, and minimal disruption when it comes to electrical installations.
We fit RCBO consumer units that have many benefits.
Any other type of consumer unit (usually Dual RCD) have some serious drawbacks.
That is why we only install RCBO Consumer Units, ensuring the best possible protection for your home or business.
If we have already fitted your consumer unit – congratulations, you are benefiting from the superior safety and convenience of RCBO technology.
However, if you still have an older Dual RCD board or even a fuse box with no RCD protection, it’s important to understand the risks involved.
Drawbacks of Dual RCD Boards
Widespread Power Loss
A fault on one circuit can trip half of your consumer unit, leaving large parts of your home without power.
Limited Protection
Unlike RCBOs, Dual RCD boards don’t protect against overloads or short circuits on individual circuits.
Not Future-Proof
As electrical demands increase, Dual RCD setups struggle to provide adequate protection for modern electrical loads.
RCBOs - the Superior Choice
Individual Circuit Protection
RCBOs protect each circuit separately, meaning if a fault occurs, only the affected circuit trips. This prevents unnecessary power loss to other areas of your home.
Minimal Disruption
Unlike Dual RCD boards, where one fault can cut power to multiple circuits, RCBOs ensure the rest of your home remains powered, avoiding the frustration of widespread outages.
Precision Safety
RCBOs protect against both residual current (earth faults) and overcurrent (short circuits and overloads), giving you complete protection for each circuit. Dual RCD boards, in contrast, only protect against residual current, leaving your system more vulnerable.
Greater Flexibility & Future-Proofing
RCBOs are suitable for all electrical installations, whether residential, commercial, or industrial. If you plan to upgrade your home with solar, battery storage, EV charging, or additional circuits, an RCBO board is the best foundation for a safe, scalable electrical system.
Understanding Electrical Protection
Common dangers and how an RCBO Consumer Unit tackles them:
Individual Circuit Protection
The danger: too many appliances running on the same circuit can make cables overheat. For example, plugging heaters, tumble dryers and kettles into one ring circuit.
The protection: MCBs (Miniature Circuit Breakers) and RCBOs measure current. If the demand is higher than the cable can safely handle, they trip before overheating can cause fire.
Short Circuit Protection
The danger: When a live wire directly touches neutral or earth, the current in rush spikes massively - hundreds of amps in an instant causing heat and arcs.
The protection: MCBs and RCBOs react almost instantly to disconnect the supply, stopping wiring damage, fire, or electric shock from the fault.
Arc Fault Protection
The danger: Poor connections, damaged cables (e.g. rodent chewing) can cause tiny sparks called arcing faults. They don’t always draw enough current to trip an MCB, but arcing can reach high temps.
Protection: AFDDs (Arc Fault Detection Devices) recognise the unique electrical arcing “signature” and shut off before fire can start.
Shock Protection
The danger: direct or indirect contact with a live part can be fatal.
The protection: RCDs and RCBOs trip in under 40 milliseconds if they detect current flowing somewhere it shouldn’t - like through a person to earth. RCBOs combine RCD shock protection with overload/short circuit protection for each circuit individually.
Consumer Units: Our Work
The Callout
Mr Gatenby’s electrics had tripped and his RCD fusebox would not reset. He tried his insurance company but it was a Saturday and they had no engineers in rural North Devon to attend. We were there within an hour.
Our Response
We were on site rapidly, and assessed the issue. We tested the circuits but the fault was the RCD itself which had caused power loss to five circuits including ground floor sockets, cooker and lights – most inconvenient, especially on a weekend!
Given the fusebox was over 25 years old (and a now-obsolete fusebox Legrand brand) we recommended a new RCBO consumer unit. Charlie returned a few days later to install and test – at the same time he tested the property and provided an EICR (both were long overdue).
Benefits
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Customer Verdict
“Our old fusebox needed replacing and bringing up to modern standards as we had new rooms added and growing needs in the household.
We also wanted a way to completely shut down non-essential electrical circuits overnight, saving energy and reducing the amount of electrical interference as we sleep.
Paul and the PD Electrical team listened carefully and provided a great solution – a “kill switch” that could give a late-night closedown, whilst keeping essential circuits separated and active overnight.”
Zoë Browning, Ilfracombe
The Callout
Mrs O’Leary was an existing customer of PD Electrical. She received one of our letters reminding her to book in a electrical re-test. She got in touch and booked an EICR inspection.
Our Response
The testing showed the installation was in good condition overall with a few minor defects but we also offered her a new fusebox with the benefits and she agreed with our advise. The new fusebox work as well as fixing a few diy electrcial add ons mainly found in the garage was booked in a few days later.
Benefits
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Customer Verdict
“Our old fusebox needed replacing and bringing up to modern standards as we had new rooms added and growing needs in the household.
We also wanted a way to completely shut down non-essential electrical circuits overnight, saving energy and reducing the amount of electrical interference as we sleep.
Paul and the PD Electrical team listened carefully and provided a great solution – a “kill switch” that could give a late-night closedown, whilst keeping essential circuits separated and active overnight.”
Zoë Browning, Ilfracombe
“Our old fusebox needed replacing and bringing up to modern standards as we had new rooms added and growing needs in the household. We also wanted a way to completely shut down non-essential electrical circuits overnight, saving energy and reducing the amount of electrical interference as we sleep. Paul and the PD Electrical team listened carefully and provided a great solution – a “kill switch” that could give a late-night closedown, whilst keeping essential circuits separated and active overnight.”
Zoë Browning, Ilfracombe
Consumer Units FAQs
Why do I need a new fusebox? I had one three years ago!!
Unfortunately even a recently-fitted consumer unit can lack some key features that are important for safety, compliance and prevention of inconvenience in the event of a fault.
Regulations have changed a lot in the last few years with Amendment 2 coming in – BS 7671:2018+A2:2022 took effect on 28 March 2022.
Vitally-important features are:
- Metal case for fire safety especially if the fuse-box is located near a fire exit.
- Surge protection devices protect electronic equipment from transient over voltages or “spike” in the grid – LED lighting is susceptible and needs protection.
- Circuit protection needs to be balanced correctly between not causing inconvenience in the event of a fault but at the same time taking life-saving action in cutting the power to a circuit when needed.
- Previous consumer unit setups have multiple circuits fed from one sensitive RCD device that when trips removes power to multiple circuits which is a real pain as well as increasing fault-finding time – the solution to this is individual circuit protection or RCBOs.
What’s the difference between an RCD and an RCBO?
An RCD (Residual Current Device) protects several circuits together combined with MCBs (Miniature Circuit Breakers)— if one trips, it can cut power to healthy circuits too.
An RCBO (Residual Circuit Breaker with Overload) protects each circuit individually, so only the faulty one shuts off. This means more safety, less disruption, and easier fault-finding.
Both offer life-saving shock protection.
Do I need Surge Protection in my fusebox?
Yes – most homes now do. The latest wiring rules (Amendment 2, BS 7671) expect a Surge Protection Device (SPD) in all new fuse boxes.
An SPD protects your electronics (boiler, Wi-Fi, TV, LED lighting, chargers, etc.) from damaging voltage spikes. Inside, it uses a component called a metal oxide varistor (MOV), which stays idle in normal use but instantly diverts any surge safely to earth.
SPDs can absorb lots of small surges over time. Only a very large surge (like a nearby lightning strike) will sacrifice the device, at which point a window on the front changes from green to red to show it needs replacing.
They’re a low-cost way to avoid expensive damage and keep your electrics protected.
Is an SPD a one-time thing, like a fuse?
No — an SPD (Surge Protection Device) is designed to take lots of small voltage spikes over time by safely sinking them to earth.
It only sacrifices itself during a very large surge, like a nearby lightning strike. If that happens, the SPD’s indicator window on the front will change colour from green (normal) to red, to show it needs replacing.
In normal use, it just keeps protecting your circuits in the background without needing regular replacement.
What is inside an SPD? How does it work?
SPDs use a metal oxide varistor (MOV). This component normally sits idle, and connects between Live and Neutral and Earth, but when a voltage surge occurs, the MOV suddenly becomes conductive between Live and Neutral to Earth, safely diverting the excess energy away to Earth.
After the surge passes, it returns to a high-resistance state. Over time, repeated surges slowly wear the MOV down, which is why SPDs include an indicator to show if they are still healthy or need replacement. The SPD will start conducting at around 270-300 volts.
Will I need my power off for long during replacement?
Yes – we will need to isolate the supply, but a fusebox change takes most of a day.
It is not just replacing the fusebox – we also carry out testing on all the circuits fed from the fusebox which means power will be on and off for the duration.
We will get everything back on safely and issue the correct certification once complete. We do provide high-capacity power banks that our customers can use to keep their router, fridges or computer running, minimising the inconvenience.
Is it law to upgrade my fusebox?
No. There is no law to say you must upgrade your existing fusebox nor carry out routine testing.
We as electricians can only offer our advice and explain the advantages of a new unit.
An old fusebox can become unsafe over time or become obsolete – then it can prove difficult to get a replacement part when needed.
Do I need a new fusebox for Solar Panels or an EV charger?
Sometimes, yes. Solar and EV chargers cannot be fed from a rewireable fuse and an up-to-date circuit breaker must be used in line with manufacturers instructions.
Extra circuits for solar, batteries or EVs will need their own dedicated protective devices. If your current fusebox doesn’t have the capacity or right protection, a new one ensures safety and compliance.
What certificates do I get with a new fusebox?
When we change a fusebox and install a consumer unit we often will test the circuits and issue an EICR (Electrical Condition Report) first.
This is so we can code any existing faults found, ready for them to be addressed.
Once all faults found are addressed we issue an Electrical Installation Certificate (EIC), plus Building Control Notification through NICEIC.
This proves the work is safe, tested, and compliant with current regulations. A new fusebox can involve quite a bit of paperwork.
How do I know if my fusebox is out of date?
Signs include:
- No RCD protection
- Plastic casing (instead of metal)
- Circuits tripping regularly
- Old rewireable fuses instead of modern switches.
It is best we check it as part of a Free Home Safety Check.
How much does a new fusebox cost?
Prices vary depending on size, number of circuits, and extra features (like surge protection or AFDDs).
We can provide a fixed-price quote, including all parts, labour, testing, and certification.
My fusebox has been fine for 40 years with no issues — why change it now?
It is true that older fuseboxes can keep working for many years, but “working” doesn’t always mean “working safe”.
A 40-year-old unit won’t have modern protections including:
- RCDs or RCBOs to prevent electric shock
- Surge protection to guard your electronics
- Metal, non-combustible enclosures to reduce fire risk
Why do I need to have a retest after 5 years?
Electrical installations don’t usually fail overnight – problems build up slowly with wear, damage, or changes in use.
The 5-year retest (EICR) is there to catch issues before they become dangerous.
Protective devices like RCDs are electro-mechanical devices which can seize up over time is not tested – if it seizes up then it doesn’t offer protection when most needed!
OK, I understand what an RCBO is — so what’s an AFDD?
An AFDD (Arc Fault Detection Device) is a newer type of protective device designed to stop electrical fires. Think of it as an RCBO with extra fire detection ability.
While RCBOs protect against electric shock, short circuits and overloads, an AFDD also looks for dangerous arcing faults — tiny sparks caused by loose connections, damaged cables, or crushed leads.
These arcs can build heat without tripping a normal breaker, but an AFDD detects the signature of the arc and cuts power before it can start a fire. They are now required in higher-risk buildings (like HMOs, student accommodation, and care homes).
Our Google Reviews
Paul’s knowledge and expertise really stood out, which gave me complete confidence in the work being done. My main problem was the fuse box constantly tripping and cutting power to several circuits at once. Paul recommended upgrading to a modern RCBO consumer unit, which has been the perfect solution — now each circuit is individually protected. This has made a huge difference, especially as I work from home and can’t afford interruptions to my computer equipment.
The new setup gives me real peace of mind knowing everything is up to date, safe, and reliable. I hadn’t even heard of an RCBO before, but now I wouldn’t want to be without one. I’d happily use PD Electrical again and highly recommend Paul for anyone needing a trustworthy, knowledgeable electrician.
Paul came on the afternoon of my call , and provided me with an estimate for installing a EV Charger and upgrading my Electric fuse box. Four days later Charlie & Ryan attended and completed both jobs. The quality of their work was first class, and at a better price than my previous estimates!
An excellent company I strongly recommend!
Very different from a previous experience with an electrician - long wait to get the job done and not done efficiently.
Paul and his team did everything perfectly. We will use him in future for any electrical jobs.
I would without reservation highly recommended him.
Review edit January 2025- having had occasion to rely on Paul's after sales services I agree with his claims for customer care and reliability, Paul can be totally trusted to deliver as promised.
Had a quote for another job was booked in on a day and time that worked for us
Pd electrical turned up done the job very professional everything was left clean and tidy rubbish taken away
PD ELECTRICAL highly recommended
Charlie from PD arrived on time to carry out the work, he was polite, cheerful and a pleasure to have in the house (this has not always been the case with previous contractors!) Everything was completed to agreed spec and care was taken throughout not to leave any mess or cause disruption. I chatted with Paul about our fusebox and some other requirements and he gave me considered, helpful responses which encouraged me to return in future for additional works.
My day job involves encouraging my clients to "go the extra mile" for their customers and it was great to see this in action with Paul. Highly recommended, well done!
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PD Electrical
We help homeowners in Barnstaple, Bideford and Ilfracombe upgrade the electrics in their home, garden or renovation without being taken for a ride, let down or left in a mess.
Our promise to you
- Clear Fixed Prices
- Fully Certified Work
- Electrical Installation Certificates
- Full Safety Checks
- Full-quality promise
Areas Covered
- Barnstaple
- Bideford
- Braunton
- Ilfracombe
