Electrical Contracting News (ECN) August 2016 | Page 23

CABLE MANAGEMENT
To better understand this point , it is worthwhile using the example of IP4X . This rating specifi es that protection against a 1.0mm probe is required , but the cabling does not need safeguarding from the ingress of water . Therefore , IP4X may not be watertight , but it does guard against the entry of debris , which could compromise the safety of the cabling within . IP4X can also be reliably tested with a 1mm diameter probe without penetrating the trunking .
Unlike the case of IPXXD rating , gaps that occur as a result of adjoining trunking do not need protection from solid particles . The letter ‘ D ’ added to the code indicates that safeguarding from access to hazardous parts with wire should be provided . Even though physical contact with hazardous elements contained in the trunking is not allowed during tests , the 1mm diameter probe demonstrates that an IPXXD rated system remains penetrable to wire .
Therefore , it could be concluded that when an IP4X compliant system is specifi ed and installed , a more robust provision is ensured and a more reliable approach achieved .
However , the specifi cation of which IP rating to use should be made at the discretion of the electrical contractor , as there are a number of key factors to take into account that could infl uence this decision . These include :
• The level of protection required at the place of the installation .
• Type of application .
• The people who are likely to use or come into contact with the equipment .
• The suitability of the enclosure for the intended working environment .
Bespoke solutions
Given that IP4X offers higher performance in cable trunking protection , it is curious why the demand for specifying IP4X has not taken off in the market . The answer may lie in the fact that solutions , which achieve IP4X compliance have to date , been limited to bespoke cable enclosures .
Traditionally , bespoke trunking solutions involve specially designed lengths and accessories that often account for additional cost and command longer lead times . Consequently , the installation programme is lengthened because the required accessories and fi ttings are not available from distributors as standard stock . It is no surprise then that electrical contractors have largely been hesitant in embracing IP4X compliant cable containment systems .
However , advances in the cable management market offering a more practical and economical route to IP4X compliance , may signifi cantly change this situation . Existing bespoke containment solutions in standard trunking now feature off-the-shelf clips to deliver IP4X protection . Additional accessories are still required when using these clips in the bends of standard trunking , but for straight lengths , the clips can be fi tted over the joint between two lids without the need for tailored accessories . This ensures that adjoining trunking stays tightly connected for years following an installation .
There are clear advantages in specifying standard parts in any cable management system .
Benefits
In a new cable containment solution , the benefi ts of a reduced lead time resulting from the delivery of a standard trunking system equipped with compatible clips , should outweigh those of a bespoke trunking system that relies on specially manufactured accessories . There are clear advantages in specifying standard parts in any cable management system . These include ensuring that the system retains its usual product footprint , and an IP4X compliant system will be considerably quicker and more effi cient .
Another benefi t of trunking that achieves IP4X compliance by employing standardised parts , is that it is ideally suited for retrofi t projects . In existing installations , not all cable containment systems will be retrofi ttable and are dependent on the trunking that is already in place . The trunking will indicate whether the system can be made compliant by installing clips or if an extensive bespoke overhaul is required . It seems strikingly clear therefore , that retrofi ttable standard trunking with clips that achieves IP4X cost effectively in accordance with the Wiring Regulations , is the way forward .
Specifi ers can also be reassured that by meeting IP4X they provide installers and service engineers the confi dence that the system fully complies with the legal requirements of the Wiring Regulations . Electrical contractors responsible for the specifi cation and installation of cable containment solutions should choose IP4X over IPXXD as the standard for best practice .
Manufacturers could add their support by including products that affect IP4X compliance in their range . Those suppliers that provide standard product solutions , which are adaptable to IP4X ratings , are making a positive contribution to the supply chain by easing lead times , reducing material costs , and supporting a sustainable , safe and compliant cable management solution . Electrical contractors ’ ambition on any project should always be to achieve optimum specifi cation . To achieve that goal , advice is available from expert manufacturers on the most appropriate trunking solution that complies with the law and doesn ’ t compromise a project ’ s lead times .
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