LSHF materials | testing
Finding clarity in LSHF cables
There is some confusion in the cable industry regarding performance of low smoke halogen free (LSHF) cables and the materials used to produce them. Products identified as LSHF - or as low smoke zero halogen (LSZH) - have been with us for some time. However, performance claims are frequently self-certified and testing procedures may not always be standards based. More importantly, there are frequently misconceptions over what some tests actually cover. This article aims to clear up confusion through an explanation of the main international standards and their scope.
Background to LSHF LSHF cable materials originated in Europe and the US in the 1970s. During the 1980s, they were used in applications such as the London Underground mass transport system, the UK’s Royal Navy vessels, and offshore oil drilling platforms in the North Sea. Typically, LSHF cables were installed in confined spaces where the toxicity and corrosivity of smoke generated in a fire would be particularly problematic. Adoption of LSHF cable products has been slower in the US than in Europe, but that began to change as a result of some recent high-profile fires. One example, for instance was the L’Enfant Plaza Metro train incident in Washington DC on the 12 January this year, where an electrical malfunction fire filled a tunnel with smoke, killing one person and injuring many others.
www.compoundingworld.com
The numerous standards applying to low smoke halogen free cable materials have resulted in some
confusion among suppliers and users. UL specialist Robert Bellassai provides some clarification
Traditionally found in the power and control catego- ries, LSHF cable products have now branched out to include data/telecom cables, fibre optic cables and appliance wire and cable. They also are being used in locations other than the traditional confined spaces of tunnels, subways, ships, submarines and mines, with LSHF cables now frequently found in hospitals and data centres (UL will be proposing optional HF and LSHF Marking for the US 2020 National Electrical Code (NEC) revision cycle).
Asia and South America are also adopting LSHF wire
and cable, following the EU approach to cable stand- ards. In a global economy, manufacturers now have access to a standards-based LSHF cable designation and cable designers can produce a single design that can be sold and applied around the world. To better understand LSHF, it is first necessary to
consider what a halogen is in terms of the Periodic Table. The five halogen elements found in column 17 are
December 2016 | COMPOUNDING WORLD 35
Main image: The scope of international standards
covering low
smoke halogen free (LSHF)
cable materials has been frequently
misunderstood, according to
UL, leading to confusion in the market
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92
