Wire mesh versus conventional tray systems

Twenty years ago, only 10% of cables in commercial buildings were data cables; but now, that figure is closer to 60%, with electrical and cabling contractors also laying control and sensing cables in industrial buildings.

How these cables are reticulated and installed has also changed over time, with the development of new cable management systems, including wire mesh trays such as HPM Legrand's Cablofil.

The emergence of the wire mesh system delivers many advantages over conventional trays, ladder trays and perforated trays. Speed of installation and the exclusion of awkward componentry are key advantages with wire mesh systems. Minimising the number of nuts and bolts required, along with the open and light structure, contributes to making wire mesh easier and neater to assemble and potentially saves as much as 20–30% on labour costs.

Conventional tray and strut systems typically have four to eight bolts, two hold-down brackets, two strut nuts and two bolts per butt splice. On the other hand, typical wire mesh systems using splice plates and trapeze supports require no nuts and usually incorporate a hold-down clamp within the structure.

In almost all cabling installations in both commercial and industrial applications, wire mesh systems can reduce labour and hardware costs. With only a pair of bolt cutters needed, wire mesh trays can be shaped on site, rather than fabricated elsewhere and shipped to site. This avoids downtime created by ordering spare parts for other systems and enables the installation to be adapted on site to the inevitable changes that are required on site.

The open structure of wire mesh tray systems also maximises heat release, which enables design engineers to optimise power cable cross-sections, which is a significant advantage, given the dilemma of the increasing electrical demand within modern buildings in spite of reducing real estate above ceilings and other service zones.

The design developments in the cable management system are also recognised in the materials used. Conventional trays, ladder trays and cable ladders are only available in steel. To reduce the development of rust and corrosion that are common in a number of applications, wire mesh systems are typically available in a number of surface treatments and materials, such as ElectroZinc, hot dip galvanised steel and various stainless steel grades such as pickled and passivated 304 and 316, expressly required for use in corrosive environments such as marine, mining, petrochemical, heavy industry, transport and food.

Over the past 10 years, the weight of some cables has significantly decreased. Fire-rated cables for example, used to be encased in copper, but now plastic-coated fire-rated cables are standard and tray systems don't have to bear such heavy loads. Coupled with the lighter wire mesh trays (due to less physical mass), installers can be confident OHS requirements are being met.

The open structure of the mesh design also enables easier cable inspection and management. Increased visibility simplifies maintenance work (eg, add-ons or removals) and limits the retention of dust, bacteria and other debris that can obstruct the cable path.

HPM Legrand
www.hpm.com.au