Surge Protection Surge Protection Devices
There are still so many questions surrounding the use and application of surge protection devices (SPDs). Here, Kirsty Johnson MIET, technical director at Surge Protection Devices Ltd, details an introduction to what type of device is needed and when surge protection is required under BS 7671:2018 amendment 2.
What to install
There are three types of SPDs, depending on what you want to protect. If you are looking to protect a distribution board or consumer unit, it will be a type 1 or type 2 SPD. If you wanted to protect a specific piece of equipment, such as a fuse spur or single socket, it would be a type 3. A type 1 device would only be required where there is an external lightning protection system or the installation has an overhead supply. For all other circumstances, a type 2 device will be sufficient to provide adequate protection for distribution boards. Where protection against
overvoltages is required for specific equipment, a type 3 device may be used to provide protection. The requirement to install SPDs where the consequences could result in serious injury to, or loss of human life (i) is the most onerous requirement. This will mean that any distribution board supplying electrical equipment that is installed to protect life or prevent injury will require an SPD.
Indent three (iii) is similar to the previous requirement, where an SPD should be installed where commercial or industrial activity could be interrupted. The requirement now is that an SPD shall be provided where the consequence caused by overvoltage could result in significant financial or data loss.
“In practical terms, most installations will have
distribution boards that require surge protection.”
When are SPDs required? Regulation 443.4.1:
Protection against transient overvoltages shall be provided where the consequence caused by overvoltage could: I. Result in serious injury to, or loss of human life, or
II. - deleted by Corrigendum May 2023 III. Result in significant financial loss or data loss
For all other cases, SPDs shall be fitted to protect against transient overvoltages, unless the owner of the installation declines such protection and wishes to accept the risk of damage to both wiring and equipment as tolerable.
20 | electrical wholesalerJune 2023
ewnews.co.uk
The basic position of Section 443 is now that SPDs shall be installed. In practical terms, most installations will have distribution boards that require surge protection due to the indents above, so it would only be distribution boards that did not require surge protection, as no circuits outlined in regulation 443.4.1 were present. Then a discussion is encouraged between the electrical designer and the client to ensure that no unacceptable losses occur from overvoltage, while also considering the requirements to protect against switching overvoltages from regulation 443.4.2. To participate in any of the free CPD sessions offered by Surge Devices, you can contact
kirsty@surgedevices.co.uk 01484 851 747
Surge Protection Devices Surge Protection Devices Ltd and its partner companies have been solving problems in lightning and surge protection for industrial, commercial and domestic electrical installations for over 50 years. The company specialises in ISO 9001-compliant, European-designed and manufactured products which exceed the requirements of the latest standards. In addition, Surge Protection Devices hosts frequent seminars with consultants and specialist training organisations, as well as attending exhibitions and conferences both in the UK and overseas, where company representatives are well- known for their specialist knowledge.
www.surgedevices.co.uk
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