Why Surge Protection has more value to your business than you think

November 22nd 2018

Surge Protection is a key part of the 18th Edition. We discuss how using these devices will have more value for your business in the long term.

Surge Protection Devices are about to become commonplace in all types of electrical installations. The new requirements in the 18th edition of the Wiring Regulations mandate overvoltage protection in many circumstances.


For example regulation 443.4 says that protection against overvoltage must be provided where there is risk of serious injury - or loss of human life, where a large number of co-located individuals are affected, where overvoltage will result in interruptions to public services, or commercial activity or industrial activity.

Medical & care facilities such as hospitals & care homes, group living circumstances like apartment blocks & working environments such as high rise office buildings, public support organisations like 999 services, financial institutions etc are examples that the above could readily be applied to.

Therefore, the designer must consider the types of premises where the above consequences of overvoltage will apply and protect against that by providing devices such as SPD at the origin of and throughout the installation.

Even single unit dwellings require overvoltage protection if the value of the installation and the equipment connected to the installations justifies the cost of investment. This simply requires a financial judgment to be made.

Typically a single dwelling will include a lot of valuable items with sensitive components, e.g.  central heating boiler, heating controls, smoke alarms, intruder alarm, freezer, broadband, TV box, TV, games console, PCs, tablets, LED lighting, and the average cost of the electrical installation itself is around £3k. So it’s easy to justify the inclusion of an SPD.

Those of us that run a business from home will have sensitive IT equipment that also contains valuable data such as business contacts, trading accounts, invoices, receipts, salary, tax data etc all valuable information that could be at risk of loss from overvoltage.

However, an exception may be permitted for single dwelling units if the total value of the installation and the equipment connected to it does not justify the protection.

Other Circumstances & Risk Assessments

For all circumstances other than the above, the 18th edition requires the designer to carry out a risk assessment using the method explained in 443.5.

If no risk assessment is carried out then overvoltage protection must be installed. This is a valid design decision, to bypass the risk assessment stage & always fit overvoltage protection.

The 18th Edition includes set requirements for installing Surge Protection devices, and options elsewhere based on risk assessments but, perhaps the best way to determine your approach to overvoltage protection requirements is to just fit them in your next install regardless.

Wylex have a range of Surge Protection Devices that can help you comply with the 18th Edition of the Wiring Regulations and protect the valuable equipment & data in your client’s properties.

More on Surge Protection

We have more guidance on Surge Protection as well as other key topics in the 18th Edition including Arc Fault Detection Devices and the key changes in our 18th Edition Area.

See what you can discover here.

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