The British Standard Wiring Regulations clearly specify which conduit systems are to be used in particular electrical installations.  Electricians fully armed with this knowledge will feel confident in using electrical conduit in any situation where it is called for.  But if you think all flexible conduit systems are the same – think again!  Meirion Buck, design and applications manager, Adaptaflex, explains

There are many demands put upon electrical conduit way beyond simple cable management such as environmental protection, mechanical protection, fire resistance, vibration resistance and various types of liquid resistance.  You name it and there is a flexible conduit system available to meet any of these essential properties.  The application areas of conduit extend beyond traditional contracting in the domestic and commercial sectors through to specialist areas such as security, rail, machine tools, marine, offshore, data cabling and many others.

Flexible conduit and fittings have almost mistakenly become commodity items, resulting in many suppliers producing similar-looking but inferior products.  The main differentiation between these conduit systems is most obviously the price but there are many differentials between what seem to be two similar flexible conduit systems.  Many of the products that do a similar job – not surprisingly – look very similar. However, do not underestimate the level of engineering and quality of solutions offered by manufacturers.  The Wiring Regulations are very clear when it comes to flexible conduit systems and demands that they conform to the International Standard BS EN 61386.  So this should be the very first question when selecting flexible conduit systems for an installation.

The installer may not be in a position to make a fully informed decision on which one to choose. The Wiring Regulations puts the responsibility on anyone who is involved in the installation, maintenance and design of electrical installations.  They must ensure the conduit selected is completely fit for purpose.  The electrical wholesaler may equally be unaware of the many differences between different types of conduit and supply the contractor with a lower-cost, lower-quality alternative which is not suitable. Again, however, the onus is on the contractor when making the choice of which one to buy.

Using lower cost flexible conduit and fittings may lead to premature failure in the field and even more serious consequences in terms of health and safety issues.  Choosing the wrong system could result in failure through incorrect fittings detaching, fracturing due to vibration, corrosion and water ingress, any of which could lead to the need to replace the complete system.  The cost of the downtime, replacement parts, labour to fit those parts, and administration of the whole exercise by the contractor will far outweigh the cost of using better quality conduit in the first place. For the installer, higher quality conduits and fittings can be easier and quicker to install.  Higher quality threads and tighter tolerances ensure that the fittings and conduit work together as they were designed to.

So what should a contractor look for when purchasing conduit and fittings?  All electrical installations in the UK have to comply with British Standard Wiring Regulations BS7671. Within the wiring regulations, the BS EN 61386 Standard is required for all flexible and pliable conduit system conduits to ensure conformance with the requirements. BS EN 61386-1, 22 and 23 cover the requirements for electrical conduit and the particular requirements for flexible, rigid and pliable conduit.

Many claim conformance to this standard but how can you be sure? Look for the Kitemark!  Adaptaflex works very hard and invests heavily in testing and meeting approvals to guarantee that all their products, which are all made in the UK, fully comply with this standard. Since 1996 all products have been continuously quality assured through the BSI Kitemark scheme type approval. The Kitemark is one of the world’s premier symbols of trust, integrity and quality. This ensures all products manufactured will always exceed the minimum performance criteria of the standard.

A good guide is also to check whether there are any third-party approvals as these indicate a level of approval not achieved with the self-certification process that many manufacturers have adopted. Adaptaflex is proud that through the BSI Kitemark scheme they are unique amongst UK conduit manufacturers in having third party independent testing and approval.  The company continuously invests in third party testing to comply with many other technical and engineering requirements such as the London Underground fire regulations for rail and Lloyds Type approval for marine applications as well as many other national and international standards.

It is absolutely vital contractors make sure that the conduit that they buy or install is appropriate for the application.  Although many manufacturers produce a multitude of different grades of conduit they are not all the same and are all developed with specific applications or target prices in mind. Using over-specified conduit may not be the most cost effective result but cutting corners by purchasing a lower grade of conduit that is not fit for purpose could result in an expensive failure.

It is also vital to specify the right fittings, otherwise the conduit may pull out, or there may be an inadequate seal.   ‘Mixing and matching’ conduit and fittings from different suppliers is also very risky because, although the products may look similar, there could be small dimensional differences that make the products incompatible, resulting in reduced pull-off strength, inadequate sealing, or installation problems.  All of which can result in a return visit and even a strip out and replace of the installation

If support is needed on a particular application, Adaptaflex will provide highly informative catalogues clearly detailing approvals, applications, IP ratings, temperature ranges, UV resistance, flexibility and fatigue life, fire performance and EMI screening capabilities and which conduit should be used for a specific application. If for any reason the installer is at all uncertain of the right conduit system to use then he can contact the Adaptaflex Technical Support Team. They will provide specific advice in choosing the system that meets the application, environmental criteria, technical specifications and approvals to give the most cost effective solution for the installation.

Information is available through a wide variety of media, through help desks to its website and including social networking sites.  Adaptaflex offers helpful advice, training and generally a level of technical service that other manufacturers of cheaper conduit simply do not offer. This reflects the extensive product research & development and testing facilities, as well as the technical expertise of a company that truly understands conduit and its applications.  Although the various products on wholesaler shelves may look similar, installers should be aware that there can be significant differences in overall quality – any difference in price has to be accounted for and the saying that you get what you pay for is not far off the mark.

So the installer has made his choice – perhaps with assistance from a manufacturer – and has placed his order with the wholesaler.  One last word of advice: check that what is given is what was ordered!  After all, the installer does not want to be blamed for an installation failure that has arisen because somebody else has provided an inferior-quality alternative. A visual check of the packaging – or even the conduit itself – will normally show the manufacturer’s name, manufacturing number for traceability and the all-important Kitemark.