SPECIAL FEATURE
CABLING & CABLE MANAGEMENT
UNDERSTANDING THE UPDATES TO THE 18TH EDITION British cable manufacturer, Marshall-Tufflex, is urging professionals to familiarise themselves with the latest updates to Amendment 2 of the 18th Edition of the IET Wiring Regulations before the previous Edition is withdrawn in September. In this article, the company’s National Specification Manager, Barry Roberts, takes a closer look at what the cable regulations are and how to ensure an installation is compliant.
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ublished in March this year in a newly coloured brown cover (replacing the previous blue), the Institution of Engineering and Technology (IET) and the British Standards Institution (BSI) have introduced Amendment 2 to BS 7671:2018 18th Edition of the IET Wiring Regulations, with the aim of making the regulations easier to understand and, therefore, ensure compliance and safety throughout the industry. Amendment 2 came into effect immediately on 28 March 2022 and among the updates is a more detailed requirement for fire safety, specifically introducing a new concept of ‘protected escape routes’. The updated guidelines, detailed in Regulation 422.2.1 with further information provided at Appendix 13, defines a protected escape route as a passage of safety enclosed with fire-resisting construction designed by a fire engineer or architect, to provide designated protection against fire for a specified period and longer than a standard corridor. To create a ‘fire sterile’ safe passage of escape, the updated regulations outline new requirements for the type of cabling in these routes and mandates that cable management in these areas must limit smoke and flame. To comply with this when specifying cable management systems for protected escape routes, only select products that are classified as non-combustible and are certified as such can be used, as follows:
Regulation 521.10.202 specifies that cables must only be secured using metallic clips
BS EN 61386 for conduit systems • BS EN 5085 for cable trunking and ducting • BS EN 61537 for cable trays and • cable ladders Powertracks must meet the • requirements of BS EN 61534
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It is important to understand that predetermined fire escape routes are not a fix-all solution
The introduction of ‘protected escape routes’ is a further positive step in improving safety and saving lives for building occupants, but it is important to understand that predetermined fire escape routes are not a fix-all solution for adequate occupant protection in a fire situation. That is why the IET also updated its BS 7671:2018 Regulation 521.10.202, which came into effect in January 2019. Regulation 521.10.202 places emphasis on minimising the risk of overhead cable collapse in the event of a fire. In this scenario, fallen, hanging or trailing cables can block escape routes – not only hindering escape, but also by preventing the fire services from safely entering and exiting the building swiftly. As such, Regulation 521.10.202 stipulates that cables must be supported throughout the cable management installation across the entire building, and not just in escape routes. Furthermore, all products must also satisfy the requirements of the Construction Products Regulations (CPR) in relation to their reaction to fire. To some extent, the issue of cable collapse was recognised in previous iterations of the Wiring Regulations, which required the installation of fire clips to cables along pre-designated escape routes. However, following a number of injuries and the tragic death of a firefighter as a result of collapsed cabling, BS 7671:2018 Regulation 521.10.202 specifies that cables must only be secured using metallic clips. Metallic clips must also be used on metal units,
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even when supported on metal cable trays or ladder racks. Cables not housed within these structures will need to be securely attached to the structure of the building using fixings that will not be destroyed by fire. It is important to note that whilst most metal fixtures are accepted, those made from aluminium are not compliant due to the material’s low melting point. Whilst electrical professionals are not expected to be fire experts, there is a necessity for everyone involved in every aspect of building design and installation to acknowledge the role they play in ensuring the safety of building occupants and adhering to regulations. With Amendment 2 of BS 7671:2018 in place since 28 March 2022, the previous version (BS 7671:2018+A1:2020) will be withdrawn on 27 September 2022, so it is vital that electrical professionals ensure they become familiar with the changes before then. Marshall-Tufflex manufactures a wide range of solutions that meet fire safety and the requirements of the latest Edition of the Wiring Regulations. Its range of metal Firefly Clips and straps, conduit, trunking, trays, ladders and powertracks are all certified to quality British Standards and the company’s specification team can work with contractors to discuss and advise on technical issues, product standards, data cabling control and compliance for each application. Marshall-Tufflex, marshall-tufflex.com
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20/07/2022 10:37
