Cable management - The bigger picture

06/03/2015

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When it comes to specifying cable management systems, there are a number of key areas to consider in addition to cost per unit and installation time. Here, Nigel Leaver, lead marketing manager for cable management at Legrand, comments on the changing face of cable management and the importance of considering the whole picture at the specification stage.

With today’s fast track projects and construction jobs, M&E contractors and specifiers are constantly on the lookout for solutions which not only minimise cost, but also time spent on site. However when it comes to cable management, no two installations are the same so it’s vitally important that contractors and specifiers don’t solely focus on product cost and installation time, but instead take a holistic view of the application to ensure the correct system is selected from the outset.

Location

One of the first key considerations is to determine what elements a cable management system will be exposed to. Any cable management system installed externally, or even in corrosive or marine environments such as offshore rigs or coastal locations, needs to have the relevant treatment in order to withstand such conditions. A deep galvanised or stainless steel product is therefore recommended in these circumstances.

It’s also important to consider what type of cable will be used throughout the installation and if support or protection is needed. For example, single insulated (non-sheathed) cables require additional mechanical protection, as well as support. A distribution trunking system is generally the solution of choice, as it fully encases the cables providing both high level protection and is also ideal for tamper-proofing essential supplies. If using armoured cables, an open cable management system, such as wire mesh or cable ladder, is considered more suitable.

Weight

Weight is obviously an important aspect to consider when analysing the overall protection of a cable management system. However this means calculating the total load that the cable management system will be subjected to, now and in the future, and not just the weight of the cables being supported.

The total load should be calculated based on not only the weight of the cables, but also any ancillary items that are subsequently fitted to the cable management system, such as light fittings. For external applications, it is also advisable to take into consideration potential dynamic loads, such as wind or snow that the cable management system may be exposed to.  

Regulations and Standards

Cable management legislation is not only in place to maintain high levels of cable performance, but also to protect the end user. Wiring regulations can differ depending on the installation or location of the project you’re working on, so reviewing the necessary guidelines should form part of an electrical contractors due diligence prior to any installation. Regular research of these requirements is important, as wiring regulations are constantly reviewed and updated every few years, which allows governing bodies to keep pace with technology advances and future requirements.

One example of this is the recent change to the wiring regulations that affect the use of conduit, ducting or trunking when using certain cable types. Compliance to IP4X or IPXXD when specifying a trunking system that could contain non-sheathed cables either from the outset or as an addition in the future, is an absolute must. Both aim to provide a specific degree of mechanical protection from the ingress of solid objects and prevent disruption of contained cables.

Implementing a cable management installation which meets the latest regulations and the relevant product standards will help minimise the risk of system non-compliance with any future expansion works.

Scalability

Scalability is also key, and should not be confused with over specification. All too often, specifiers build in redundant capacity instead of designing a facility that can operate efficiently now, and adapt quickly in the future. Scalability means specifiers and electrical contractors can implement a cable management system that can evolve with future needs, rather than fully anticipate them from day one. Planning ahead not only has the potential to reduce running costs, but also capital expenditure whilst ensuring the site is capable of meeting the demands of both today and tomorrow with relative ease.

Also, take the time to look closely at retrofitting capabilities. Retrofitting can become an expensive and time consuming operation if you’re using the wrong cable management system. Not all systems can be integrated with one another, so carefully analyse each at specification stage to make sure it has the ability to interface easily with any other systems that may be installed within the structure.

It’s important to note that in some circumstances, scalability isn’t just a consideration of future needs, but can also be a consequence of certain regulations. For example, when using a trunking system, a space factor of 45% must not be exceeded,as the remainder must be reserved for adequate ventilation. Without the necessary space, this can become a potential fire hazard. The wiring regulations provide methods and factors to determine the current carrying capacity based on several factors such as arrangement of cables, number of circuits and type of cable containment.

System ease of use

This may sound obvious, but always look for a cable management system that has a full range of accessories to choose from so that you can select the brackets, fixings and couplers most appropriate for the installation, from one source. In addition, take the time to work with your supplier to ensure you specify the correct amount of fittings, brackets and fixings in order to prevent delays on site.

Remember to also consider the total installed cost and look for easy fit systems that will save on installation time. For example, when selecting a trunking system, consider features such as slotted ends that accept pre-fitted couplers, rapid fit covers and push-fit spring-loaded turnbuckles. Multi-head, shake proof screws aid installation flexibility with a built-in serrated flange that bites into the steel to help earth continuity. Where these are pre-assembled to couplers and fittings, and are backed off ready to accept the next component, there’s no longer any risk of a time consuming hunt for mislaid screws.

Needless to say, manufacturers are investing heavily in product development to help meet the needs of every application, as well meeting the needs of the installer. With this in mind, Legrand has recently launched Swiftclip, which forms part of the UK market leading Swifts cable tray range, as a fast-fit alternative to the traditional nut and bolt. Swiftclip not only requires no tools during installation, but with just two clips per joint, takes less than 30 seconds to install, reducing the number of components needed and the total installed cost.

In truth, cable management specification is often viewed as an afterthought rather than an essential component that can help to enhance cable performance, longevity and future flexibility in terms of business growth. There isn’t a “one solution fits all”, so it is vitally important that the correct system is chosen from the outset. With this in mind, M&E contractors should take a holistic view of the whole installation, factoring end-user requirements and the building’s purpose into the decision making process, as well as time spent on site. If in doubt during specification, consider approaching a reputable manufacturer who not only offers an extensive range of cable management systems, but can provide expert technical support, pre and post installation.  

By selecting a cable management system that excels in each of these areas, you will not only have a system that reduces installation time, and therefore total installed cost, but you will also have a system that can meet your needs today and tomorrow.

For more information of Legrand’s range of cable management solutions please visit www.legrand.co.uk or call 0345 605 4333.