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Protect your business, property, and critical equipment from damaging power surges with professional surge protection solutions.
BS 7671:2018 (18th Edition of the IET Wiring Regulations) requires Surge Protection Devices (SPDs) where surges could cause serious injury, equipment damage, or operational disruption.
Power surges can be silent killers of electrical systems, damaging equipment, causing costly downtime, and even posing serious safety risks. Whether caused by lightning strikes, grid switching, or internal electrical faults, these sudden voltage spikes can destroy sensitive electronics, disrupt business operations, and lead to expensive repairs.
Installing Surge Protection Devices (SPDs) ensures your business stays compliant with UK electrical regulations, protects valuable equipment, and reduces the risk of unexpected system failures.
Surge protection is not just recommended—it’s required in many cases under BS 7671:2018 (18th Edition of the IET Wiring Regulations).
The standard states that SPDs must be installed where the consequences of a surge could lead to:
✔ Serious injury or loss of life – Healthcare facilities, care homes, and public buildings.
✔ Significant disruption – Data centres, commercial buildings, and industrial sites.
✔ Major financial loss – Businesses relying on high-value equipment.
For other properties, a risk assessment must be conducted to determine whether surge protection is necessary. If an assessment is not carried out, SPDs must be installed by default to ensure compliance.
Other key standards that apply to surge protection include:
📌 BS EN 61643-11 – Covers SPD testing and performance requirements.
📌 BS EN 62305 – Lightning protection and transient overvoltage risk assessment.
📌 BS EN 50550 – Power overvoltage protection devices.
⚡ Prevents Costly Equipment Damage – Protects computers, machinery, security systems, and other electronics from sudden voltage spikes.
⚡ Reduces Downtime & Business Disruptions – Prevents power surges from taking down critical systems.
⚡ Improves Workplace Safety – Minimizes the risk of electrical fires and equipment failures.
⚡ Ensures Regulatory Compliance – Meets BS 7671:2018 and other electrical safety standards.
⚡ Extends Equipment Lifespan – Protects expensive electronics and infrastructure from premature failure.
⚡ Essential for Buildings with Lightning Protection – If a lightning protection system is in place, surge protection must also be installed to prevent dangerous voltage spikes from entering the electrical system.
Unlike other electrical protection devices, SPDs do not reset after an overvoltage event.
Once a surge protection device has done its job, it must be replaced to maintain protection.
🔹 SPDs cannot be tested for effectiveness once they have taken a surge.
🔹 A failed SPD leaves your system unprotected against future surges.
🔹 Regular inspections are essential to ensure your SPDs are still functional.
This is why ongoing maintenance and scheduled replacements are crucial for keeping your surge protection system effective.
Different types of SPDs are used at different points in an electrical system to ensure complete protection:
🔹 Type 1 SPDs – Installed at the main incoming supply, designed to handle large surges from direct lightning strikes.
🔹 Type 2 SPDs – Installed at distribution boards, protecting circuits from transient surges.
🔹 Type 3 SPDs – Installed at the point of use, safeguarding individual equipment such as servers, IT systems, and medical devices.
For full protection, a coordinated system of Type 1, Type 2, and Type 3 SPDs is often required.
Yes! Surge protection can be added to existing electrical installations without the need for a complete system overhaul.
Retrofitting SPDs is:
✔ Cost-effective – Protects your infrastructure without major rewiring.
✔ Minimal disruption – Can often be installed without shutting down operations.
✔ Flexible – SPDs can be fitted at the main panel, distribution boards, or individual circuits based on risk assessment.
If your business does not currently have surge protection, retrofitting is highly recommended to meet compliance standards and protect your assets.
Protect your electrical installation and appliances with the correct surge protection for your building.
✔ IET Code of Practice compliant surge protection devices.
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Power surges can cause serious damage to electrical systems, disrupt business operations, and even pose safety risks.
BS 7671:2018 (18th Edition of the IET Wiring Regulations) outlines when and where surge protection devices (SPDs) should be installed to safeguard buildings, equipment, and occupants.
In this section, we answer common questions about surge protection, including UK regulations, risk assessments, SPD types, and installation requirements.
Whether you’re protecting a commercial, industrial, church or residential property, our expert insights will help you understand the importance of proper surge protection and compliance.
Surge protection devices (SPDs) protect electrical systems and equipment from voltage spikes caused by power surges. These surges can be triggered by:
⚡ Lightning strikes
⚡ Power grid switching operations
⚡ Faults in the electricity supply network
⚡ Turning high-power equipment on and off
Without SPDs, surges can damage sensitive electronics, disrupt business operations, and even pose safety risks. Installing surge protection helps prevent costly repairs, downtime, and data loss.
In the UK, BS 7671:2018 (18th Edition of the IET Wiring Regulations) sets out the requirements for surge protection. The regulations state that:
📌 Surge protection must be installed where the consequences of a surge could result in:
📌 A risk assessment should be carried out in other cases to determine if surge protection is necessary. If an assessment isn’t conducted, SPDs must be installed by default.
BS 7671:2018 makes surge protection mandatory in situations where a power surge could:
✔ Endanger human life – Such as hospitals, care homes, or sites with life-supporting equipment.
✔ Cause major disruption – Public services, data centres, or manufacturing facilities.
✔ Result in costly damage – Industrial plants, commercial buildings, and high-tech environments.
For domestic homes, surge protection is not always mandatory, but a risk assessment should be carried out to determine if it is necessary.
A risk assessment evaluates whether surge protection is needed in a particular installation.
It considers:
🔹 The likelihood of a surge occurring (proximity to power lines, lightning exposure).
🔹 The impact of a surge on safety (could it cause an electric shock or fire?).
🔹 The cost of equipment damage (high-value electronics, data centres, or security systems).
If the risk is unclear or difficult to quantify, BS 7671 recommends installing SPDs by default.
A risk assessment evaluates whether surge protection is needed in a particular installation.
It considers:
🔹 The likelihood of a surge occurring (proximity to power lines, lightning exposure).
🔹 The impact of a surge on safety (could it cause an electric shock or fire?).
🔹 The cost of equipment damage (high-value electronics, data centres, or security systems).
If the risk is unclear or difficult to quantify, BS 7671 recommends installing SPDs by default.
Some locations are at higher risk due to the nature of their operations or the sensitivity of their equipment.
These include:
✔ Hospitals & Care Homes – Protecting life-critical equipment.
✔ Offices & Data Centres – Preventing damage to IT infrastructure and servers.
✔ Manufacturing & Industrial Sites – Avoiding production line disruptions.
✔ Shops & Businesses – Protecting security systems, card readers, and electronic tills.
✔ Schools & Universities – Shielding lab equipment, servers, and audiovisual systems.
✔ Smart Homes & Modern Residential Properties – Safeguarding home automation, solar inverters, and EV chargers.
For businesses and commercial sites, surge protection is highly recommended to minimise downtime and financial loss.
Yes, but not all surge protectors provide lightning protection.
Type 1 SPDs are specifically designed to divert high-energy surges from direct lightning strikes into the earth, reducing the risk of electrical damage.
For buildings in lightning-prone areas, a combination of Type 1 and Type 2 SPDs is essential for full protection.
For businesses, surge protection offers several key advantages:
✔ Prevents costly equipment damage – Avoid replacing computers, servers, and industrial machines.
✔ Reduces downtime – Keeps operations running smoothly with minimal disruptions.
✔ Protects sensitive data – Avoids data corruption caused by sudden power spikes.
✔ Enhances electrical safety – Reduces fire risks and protects employees from electric shock.
Surge protection is a cost-effective investment that helps businesses avoid expensive repairs, lost productivity, and insurance claims.
Surge protection should always be installed by a qualified electrician.
The process involves:
1️⃣ Assessing the risk – Determining what type of surge protection is required.
2️⃣ Selecting the right SPD type – Installing Type 1, 2, or 3 devices depending on the application.
3️⃣ Connecting SPDs to the electrical system – Ensuring proper installation at the main distribution board or individual circuits.
4️⃣ Testing & certification – Verifying that the SPDs are correctly installed and providing protection.
BS 7671:2018 specifies installation methods and testing procedures to ensure compliance and effectiveness.
Many insurance providers require or recommend surge protection for commercial buildings and high-risk environments.
Having surge protection in place:
✔ Reduces the risk of claims – Lowering the likelihood of electrical damage.
✔ Demonstrates due diligence – Showing compliance with BS 7671 and risk management best practices.
✔ May qualify for premium reductions – Some insurers offer lower rates for buildings with certified surge protection.
Keeping certification records of surge protection installation and testing can be valuable for insurance claims and compliance audits.
In addition to BS 7671:2018 (18th Edition of the IET Wiring Regulations), several other standards apply to the design, installation, and performance of Surge Protection Devices (SPDs):
📌 BS EN 61643-11 – Covers the requirements and testing methods for low-voltage surge protection devices connected to power distribution systems.
📌 BS EN 62305 (Lightning Protection Standard) – Provides guidance on risk assessment and protection against transient overvoltages caused by lightning strikes. It works alongside SPDs in lightning protection systems.
📌 IEC 61643-12 – Details the selection, installation, and coordination of SPDs to ensure effective surge suppression.
📌 BS EN 50550 – Covers the requirements for voltage limiters (POP – Power Overvoltage Protectors) used alongside SPDs.
📌 EU Low Voltage Directive (LVD) 2014/35/EU – Ensures that SPDs meet safety requirements for electrical equipment operating between 50V and 1000V AC.
These standards ensure that SPDs are tested, installed, and maintained correctly to provide reliable protection against transient overvoltages in electrical installations.
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Our qualified electricians provide risk assessments, surge protection installation, and compliance testing to keep your property, equipment, and employees safe.
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