Networks Europe Issue 13 January/February 2018 - Page 33

STANDARDS By Networks Centre with thanks to Mike Gilmore, MD, e-Ready Building Ltd A look at the changes in British Standards relating to fire performance and telecommunications cables On 30th November 2017, an important amendment to BS 6701 (Telecommunications equipment and telecommunications cabling – Specification for Installation, Operation and Maintenance) was released: BS 6701:2016 AM1 2017. This had been anticipated by the industry throughout the year, and this article attempts to explain some of the relevant changes, and the reasons and implications for stakeholders involved with data cabling installations. The amendment is the culmination of work that has been going on since July 2016 by the industry, in particular by suppliers, to ensure their telecommunication cables meet the requirements of the Construction Products Regulations (EU305/2011) also known as CPR. IT INFRASTRUCTURE EuroClass rating Everyone in the industry should be aware that telecommunications cables, intended for permanent incorporation within constructions and placed on the market after 1st July 2017, must have a EuroClass rating as defined by BS EN 13501-6: 2014. The rating system was an extremely positive development because it addressed all the essential characteristics of a cable’s reaction to fire within one template; i.e. flame propagation, heat release, smoke production and its transparency, flaming droplets and acid gas evolution. While these characteristics were covered by existing BS EN standards, each aspect had to be referenced separately e.g. BS EN 60332 standards for flame spread, BS EN 61034 standards for smoke and BS EN 60754-2 for acid gas. The EuroClass utilises some of these standards. In particular, flame spread on a single cable continues to reference BS EN 60332-1-2, but the bunched/bundled cables tests of the BS EN 60332-3 standards have been rejected in favour of BS EN 50399. This differentiation of tests applied to single versus bundled cable is particularly relevant to telecommunications. Cables meeting the single cable flame spread requirements of BS EN 13501-6 are designated EuroClass ‘Eca’, but if they also meet the minimum heat release requirements then they are classified EuroClass ‘Dca’ and then be subjected to the additional smoke (s), flaming droplets (d) and acid gas evolution (a) characteristics. Cables that meet increasingly demanding bundled cable tests for flame spread are designated as EuroClass ‘Cca’, ‘B2ca’ or ‘B1ca’ – also including the ‘s’, ‘d’ and ‘a’ sub- classifications. SOFTWARE & SERVICES 33