Electrical Contracting News (ECN) April 2017 - Page 51

CABLE MANAGEMENT

SPECIAL FEATURE

IPXXD enclosures are subject to the same test , but the probe ( no greater than 1mm in diameter ) is allowed to enter the trunking provided it does not touch any hazardous parts – ie . a non-sheathed cable . Therefore , the protection offered by an IP4X system is greater than that of one that meets the IPXXD standard .
Specification shortfall
There are many reasons for the lack of compliance being reported on electrical installations designed after 1st January 2012 . The first is lack of specification . More often than not , there will simply be no mention of IP4X or IPXXD in cable management specifications , other than the statutory statement of compliance to BS7671 . This could be down to lack of awareness , and the industry does need to do more to make sure that consultants are up to speed with the latest requirements . Yet , too often , cable management specifications are simply cut and paste from one project to the next . Unitrunk carries out CPD presentations around the country and , unfortunately , the knowledge in the industry is often at a very basic level , which can lead to all sorts of problems .
For example , I ’ ve seen specifications in recent years that state that the cable management should be equal or approved to a named manufacturer , a manufacturer that has not been around for 20 years or more . What sort of message does that send out if that is the level of knowledge that is present in the cable management sector ?
‘ BS7671:2008 – Amendment No . 1:2011 requires the installation of IP4X trunking for all UK nonsheathed , single insulated cable trunking installations .’
Lack of contractor compliance
The second reason for installations not meeting the regulations is lack of contractor compliance . Again , this may be down to lack of awareness of the changes to BS7671 or contractors may take a view that IP4X provides an overspecified level of protection for most installations , so the market is not driving compliance either . The poor policing of the regulations means that they can install to the previous standard , safe in the knowledge that the installation is unlikely to be found out . It goes without saying that this would be a breach of BS7671 – a serious offence . Yet , it is clear that that some in the market are installing trunking systems for non-sheathed cabling that do not meet the IP4X or IPXXD standard . Non-compliant installations are continuing apace because policing of the Regulations is not consistent .
Contractors face practical problems too . If a system includes site fabricated joints , the installer must confirm the completed item meets at least the degree of protection IPXXD . What contractor carries a 1mm-wide test probe in their tool box ? How can they be sure that they have applied it with a force of 1N ± 10 % out on site ? With the best will in the world , this is just not going to happen .
Of course , contractors will be put off by the additional cost of compliance , both in terms of material and labour . While most cable management suppliers , including Unitrunk , offer an IP4X product , there is no doubt that there are added costs of manufacturing to create the required
solutions . Too often , the industry will default to the cheapest solution rather than the one that is best for the job .
It ’ s time that the industry got together and tackled this issue . It is more than four years since the Regulations came into force – either we start to enforce it or we forget about it . Unitrunk is playing its part , touring the country to carry out CPD seminars to increase education amongst the consultancy and contractor communities to help address the issue . Ultimately , the requirement must either be removed from the regulations or uniformly enforced to enable all non-sheathed cable installations to be costed on a like-for-like basis between suppliers .
If a system includes site fabricated joints , the installer must confirm the completed item meets at least the degree of protection IPXXD .