Cable Management Products Through The Years
…it is taken as read that the cable we purchase has good electrical and mechanical properties. Selection is often driven by performance in reaction to, or prevention of a fire.
Both cable and cable management systems have evolved a great deal since the 1920’s when the choice largely comprised of rubber–insulated cable. As in other sectors of the electrical products market, new and innovative products are constantly being developed and today cable management and industrial cable support systems need to perform as described, be competitively priced, cost efficient to install and adaptable enough to cope with any on–site complications.
Nowadays, we take for granted the diverse choice of cable and accessories available, not only in terms of the materials used in the manufacturing process, but also their applications. It is difficult to remember a time before PVC — it was introduced during the 1950’s — let alone rubber insulated cables. And cabling has needed to keep pace with the huge advances in technology, building design, public transportation and so on.
When making a purchase decision, these days it is taken as read that the cable we purchase has good electrical and mechanical properties. Selection is often driven by performance in reaction to, or prevention of a fire.
The availability of fire resistant cabling, as most installers would recognise it today, dates back to 1976 and the introduction of the patented Pirelli General FP200 range. It was the first cost–effective, easy–to–use range of fire resistant cables based upon an extruded insulation, which required no special installation techniques.
However the development of fire resistant cables dates back much earlier than this. In the 1950’s no cables were marketed specifically on their fire performance. Originally, asbestos heat resisting cables were promoted as being non–inflammable but this was because of their asbestos–paper tape insulation and argon–arc welded aluminium sheath. Around the same time, it was thought that newly developed PVC cables were highly resistant to fire because of the presence of chlorine in the polymer matrix. This was disproved at a serious fire at the ENEL power station in La Spezia in 1967 when the cables provided a path to spread the fire.
The advent of PVC systems really didn’t happen until the late 1960’s and early 1970’s.
After the focus shifted from preventing the propagation of fire, the 1970’s development concentrated on the smoke and corrosive and toxic fumes emitted. The first ‘low smoke zero’ halogen cables were supplied to the London Underground in 1975. Following the Kings Cross disaster, where fumes from melting fixtures, ties and cables contributed significantly to the number of fatalities, new requirements for zero halogen (LSZH) and limited fire hazard (LFH) products are now used for public buildings and similar applications.
The first international test method for fire resisting characteristics of cable was published in 1970 and mineral insulated copper sheathed cables, or designs based on extruded silicon enclosed in glass braid insulation were used.
It wasn’t until the 1980’s that standards for the installation of fire alarm systems made reference to fire resistance cables. Today, there are more than 50 types of fire resistant cable from 19 manufacturers.
The method of securing and containing cable has also radically changed since 1926. In the 1920’s and 1930’s the majority of cables were run and secured wherever it was most convenient. In the 1940’s, to improve health and safety as well as possible damage to the cables, wiring regulations called for exposed wiring to be encased in steel trunking. This led to the rise of a number of branded steel cable management products.
There are now more solutions than ever to overcome the challenges of effective cable management and cable protection. All have their merits dependant on the particular requirement of a specific application. Issues such as strength, weight, installation time, aesthetics, cost, availability, fire safety and the installed environment are among the factors that will influence the type of product used.
Steel cable management systems still account for the largest part of today’s cable management market. This includes steel conduit systems, cable/lighting trunking, cable tray, cable ladder, channel support systems and more recently wire basket tray systems.
The advent of PVC systems really didn’t happen until the late 1960’s and early 1970’s. The light and durable conduit systems quickly gained favour in domestic and light commercial applications. Conduit systems were followed by mini–trunking and larger sized industrial systems. The idea of perimeter trunking really began in the 1980’s. The first PVC systems on the market brought design and aesthetic values to cable management systems. Today there is a wealth of systems on the market, primarily used in commericial applications providing power and data to the desk. The new dado trunking systems launched by the UK market leading companies in 2006 are fully CAT 6 compliant, less expensive and quicker to install.
The other major development in the 1960’s and 1970’s was flexible conduit. As today, flexible conduit provided protection for non–shielded cable used on machinery with moving parts, underfloors or any number of specialist applications including more recently, CCTV systems.
New and innovative products are constantly being developed within cable management and industrial cable support systems, meeting the need to be competitively priced, cost efficient to install and adaptable to cope with on–site complications.Start of page
Kevin Norman is category manager at Newey & Eyre with responsibility for wiring accessories, circuit protection, data networking and industrial control and automotion products. He has vast experience in the electrical distribution business, having held a number of operational positions at electrical wholesaler Newey & Eyre over a period of 20 years. Kevin has a Bachelors degree in engineering and materials science and a Masters degree in the physics of materials.