RCDs and SPDs: The Hidden Heroes of Modern Consumer Units

When most people think about their home’s electrics, they picture switches, sockets, or maybe the light fittings. But behind the scenes, your consumer unit is working hard to keep you safe – and two of its most important components are often the least understood: RCDs and SPDs.

At Bluerock Electrical, we believe every homeowner should know what these devices do, why they matter, and how they protect not only your property but also the people in it.

What is an RCD and why is it important?

RCD stands for Residual Current Device. Its primary job is to protect you from electric shock.

Here’s how it works:

• Electricity should flow along a complete circuit, from your consumer unit, through your appliances, and back again.

• If electricity “leaks” – for example, if a person touches a live wire – the RCD detects this imbalance within milliseconds.

• It then cuts the power instantly, potentially saving your life.

Without an RCD, an electrical fault could allow dangerous current to flow through your body long enough to cause serious injury or even be fatal.

Why Type A RCDs are now the standard
In the past, Type AC RCDs were common. However, modern homes and appliances often generate DC currents – from sources like electric vehicle chargers, LED lighting, and some washing machines. DC currents can interfere with Type AC RCDs, making them less reliable.

That’s why current regulations require Type A RCDs, which continue to operate correctly even if DC currents are present. At Bluerock Electrical, we install Type A as standard to ensure you’re fully protected.

What is an SPD and why does your home need one?

SPD stands for Surge Protection Device. Its role is to protect your electrical equipment from sudden spikes in voltage, known as surges.

These surges can be caused by:

• Lightning strikes (even miles away)

• Faults in the local electricity network

• Switching large appliances on and off within your own home

While many surges are small and go unnoticed, a significant spike can:

• Permanently damage sensitive electronics like TVs, computers, smart home devices, or electric car charging equipment.

• Cause loss of important data.

• Shorten the lifespan of your appliances.

Given how much we now rely on expensive electronics, one damaging surge could cost hundreds or even thousands of pounds.

Do I really need an SPD?

For most new installations and consumer unit replacements, fitting an SPD is now the recommended standard – and for good reason. It’s a relatively small investment compared to the cost of replacing high-value electronics.

If you choose not to have an SPD installed, you’ll need to confirm your decision in writing. This is because without one, you (not your electrician) would be responsible for any damage caused by a surge in the future.

At Bluerock Electrical, we strongly recommend SPDs for any home, especially if you:

• Work from home using computers or servers.

• Own high-value appliances or entertainment systems.

• Have an electric vehicle or plan to install a charger.

Why RCDs and SPDs are the perfect safety team

Think of your consumer unit as a security system for your home’s electrics.

• RCDs protect people – cutting the power if you come into contact with dangerous current.

• SPDs protect property – shielding your electronics from costly surges.

Together, they make your electrical system safer, more reliable, and better prepared for the technology-filled homes we live in today.

The Bluerock Electrical approach

We fit Type A RCDs and SPDs as standard when installing new consumer units or adding circuits. It’s part of our commitment to:

• Your safety – protecting you and your family from electrical hazards.

• Your investment – keeping your appliances and devices safe from damage.

• Peace of mind – ensuring your system meets the latest UK regulations.

When it comes to electrical safety, prevention is always better than cure.

Is your consumer unit up to date?
If you’re not sure whether your home has modern RCDs or SPDs, we can inspect your system and give you clear, honest advice.

📞 Call Bluerock Electrical today for a free, no-obligation assessment and keep your home safe, secure, and surge-proof.