CABLE MANAGEMENT
Vital support The 3rd amendment to BS 7671 put the issue of cable management firmly under the spotlight, highlighting its potential to save lives, as well as improve the look and ease of installations By David Adams
T
he importance of cable management can seem to vary from one job to the next. Sometimes it feels like an afterthought. Sometimes it’s an important last step, ensuring cables and wiring are neatly stowed or hidden, with the best trunking solutions even adding an aesthetically pleasing final touch. But sometimes it could be a matter of life or death, as has been demonstrated in a number of tragic incidents over the past decade, when firefighters were trapped in burning buildings by cables that had fallen from walls and ceilings because the heat of the fire had destroyed enclosures and fastenings holding them in place. So the most important recent development in this area is undoubtedly the 3rd amendment to the 17th edition, which was published by the IET in January 2015 and came into force in July of that year. Chapter 52 – Selection and Erection of Wiring Systems – now states that “wiring systems in escape 36
> Cable management products are being developed to address fire safety regulations, speed up installation times and allow cables to be hidden from view
routes shall be supported in such a way that they will not be liable to premature collapse in the event of fire”. Specific reference is made in Note 1 of the amended regulation to non-metallic trunking being destroyed by fire, leading to cables falling across escape routes; while Note 2 suggests non-metallic clips, cable ties and trunking should not be used as the sole means of support. Escape routes are taken to include not just corridors, stairways and hallways, but also open areas through which people might need to pass in the event
of fire, such as general office space, shopfloors, school halls and so on. There was already a requirement for fire performance cables to be secured using metallic fixings able to withstand the same temperatures and vibrations as the cables themselves within BS 5839 Part 1, but the 3rd amendment now means that this should be extended to all fixings.
Safety first There are now many different types of fastening available that could help contractors meet their obligations cost-effectively. In places where metallic clips are needed, D-Line’s Safe-D high-temperature steel clips are an option for securing power and/ or security, CCTV or data cables. The
Winter 2015-2016 Connections
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