Fire & Safety


Charging into the electrical safetydebate


As HellermannTytonprepares to launch a new metal nail cable clip to the market, Jasmina Prill, Associate Product Manager Fastenings & Fixings, looks at why metal cable clips should become best practice for industry.


E


ver since 2005, when two firefighters lost their lives tackling a fire in a block of flats in Stevenage aſter one became


entangled in electrical cabling, the industry has been moving towards metal cable clips as an alternative to plastic. This event also led to the amendment of BS7671 of the Electrical Regulations, a body of legislation which states that wiring systems should be supported in such a way that they will not collapse in the event of a fire. This is particularly relevant for escape routes. However, while the industry has been forced


to adopt metal fixings for public buildings in line with this legislation, these rules do not cover commercial buildings, where plastic cable clips are still being used in earnest. Under BS7671 of the Electrical Regulations, cabling in public buildings must be supported by fire resistant fastenings and fixings, which are not liable to premature collapse when exposed to extreme heat. This means that plastic cable clips, non-metallic cable ties and plastic trunking to support wiring systems are no longer compliant with electrical standards. Instead, these new rules address the greater


need for safety when it comes to cable management and support in or near escape routes. It is now the responsibility of the electrical contractor to ensure that all cables and associate trunking, conduits, and cable trays, are securely attached to suitable fire-resistant parts of the building fabric, using non-combustible fixings.


30 | electrical wholesaler August 2017


While this is now mandatory for public buildings, wholesalers have a responsibility to encourage this as best practice, particularly for commercial projects.


Plastic vs metal: a heated debate One of the strongest arguments for the use of metal nail clips is the improved safety that these provide when compared with plastic clips. Products such as HellermannTyton’s new metal nail clip, for example, can withstand temperatures of well over 1000°C, whilst the melting point of plastic is typically 170°C. This means that plastic clips will melt and give way in the event of a fire far more quickly than metal clips, resulting in the release of electrical cables which are then exposed to contact. Back in 2005, after firefighters tackled a blaze


in Stevenage, an investigation found that one of them had cable insulation stuck on the palm of his glove, indicating he had attempted to untangle himself from electrical cabling that had fallen as a result of the plastic cable ties in the building melting.


Regardless of the type of project being


worked on, wholesalers are advised to stock products that meet high standards of fire resistance, particularly for escape routes and areas that may be at risk of fire. It’s also important to look at how the fixing is embedded into the building structure as installers may require metal products for more than just the cable tie, for example within cable mounts and other supporting fixings. There is no point installing a metal cable tie or clip if the wall plug connected to it is comprised of plastic, as the plug could still collapse and put lives at risk.


Adhering to modern methods of construction With the rapid pace at which new buildings are being constructed as modern methods of construction such as modular continue to grow in popularity, electrical engineers and installers are finding the time they are allowed on site decreasing. As a result, there is a growing demand for cable tie applications and fixings that are quicker and more convenient to install.


Under BS7671 of the Electrical Regulations, cabling in public buildings must be supported by fire resistant fastenings and fixings, which are not liable to premature collapse when exposed to extreme heat.


www.ewnews.co.uk


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