18TH EDITION A GREAT STEP FORWARD
Following the enactment of the BS 7671:2018 18th Edition of the IET Wiring Regulations at the beginning of this year, Mark Williams, lead marketing manager for cable management at Legrand UK, focuses on one element of the changes and what it means for building managers.
There is no doubt that the changes introduced in the 18th edition are vital to help safeguard lives in the event of a fire, and the regulations are clear in what is required, to an extent. Focused around two key chapters; 42 outlines the conditions for evacuation in an emergency and chapter 52, which focuses on the installation of cables and minimising the spread of fire.
There are some fundamental changes to the regulations, all of which apply to commercial buildings. Firstly, the requirements of the regulations now affect all wiring systems throughout a building, not just escape routes, which was previously the case. In addition, ‘wiring systems must now be supported such that they are not liable to premature collapse in the event of a fire’.
While this basic principle of the change is appropriate, there is the potential for some confusion around some of the terminology used, and how building managers choose to interpret the regulations.
For example, where the regulations require wiring systems to be protected ‘against premature collapse’, what does this actually mean? For how long should cables remain in place after the outbreak of a fire? There is currently no clear definition in the regulations of how long cable management systems must remain in-situ and support cable so it’s imperative that people across industry use their initiative and design in systems that offer the best possible solution for each and every application.
In reality, for those specifying and purchasing cable management solutions, there is the potential to over specify to ensure conformance, which is why it’s so important that industry takes the initiative to design in suitable solutions, that ensure life safety in the event of a fire, without over-specifying and without driving costs up dramatically.
Cables in or on metal containment systems are deemed to meet the requirements, but the regulations preclude the use of non-metallic cable clips or cable ties as a sole means of support. Suitably spaced steel or copper clips, steel saddles or steel ties however are all examples of what does meet the requirements.
This is a relatively simplistic view of the regulation in terms of product specification, and I would advise further study of the particular regulation, or attendance on a suitable CPD course. This is particularly true in relation to escape routes and areas prone to fire, whereby the section in the regulations covering ‘conditions for evacuation in an emergency’ has been redrafted.
To sum up, the new regulations may lead contractors and specifiers to question product suitability, but this is not a bad thing. A constantly evolving marketplace is one in which products continually develop and this will help industry to reflect on current processes and product specification to ensure life safety in the event of a fire. Creating a cable pathway through a commercial building is no mean task and it’s crucial that the market is able to support designers and engineers as well as those installing systems, to ensure conformance across industry.
For those interested in finding out more or to enrol on to Legrand’s dedicated CPD course, please visit the link below. https://www.legrand.co.uk/media/82913/cpd-creating-a-cable-pathway.pdf