Poor quality and non-compliant electric wire and cables are sold and installed throughout the world. These cables can increase the probability of circuit failure and greatly increases the risk of fire. Non-compliance is common in conductors, in insulation and in sheathing materials.
Cables provide the connectivity which keeps the lights on, air-conditioning working and the lifts running. Cables power our computers, office equipment and provide the LAN connections for computer networks, telephones, PA and communication systems. Even mobile phones need to connect with wireless GSM antennas which in turn are connected to the telecommunications network by fibre optic or coaxial cables. In addition, electric cables enable the life safety, firefighting and security systems and enable closed-circuit television.
So where can it all go wrong?
Electrical malfunctions cause 13% of residential fires in the USA with electrical distribution and lighting systems responsible for almost 50% of these fires. Of these, 67% are directly attributable to electrical wiring and its related equipment according to NFPA research. This correlates well with similar international research in developed countries although it is recognised these percentages may well be higher in countries with less stringent electrical regulation.
Insulation and sheath materials used in wire and cable are made of polymers (fuel). The Fire Triangle shows that combustible materials (fuel), oxygen (air) and ignition (spark, heat) are the only necessary elements for a fire to start.
The structure of cables
Common cable insulation and sheath materials are made from hydrocarbon (oil) based polymers. These polymers are often not flame retardant and have high calorific values (fuel element), so cable manufacturers add chemicals to make them more suited to electrical cable use. Halogens like Chlorine are good additives which help retard flame propagation and do not significantly impact the dielectric properties of the polymer, so halogens are used in both cable insulations and in cable sheaths. These halogenated polymers (example: PVC) can have a negative side effect in fire, because they will release the halogens as halides which are toxic and when combined with the moisture in eyes, mouth and lungs are very irritant. Often standard PVC cables can also release large amounts of acrid smoke.
The dangers of fire spread, toxic corrosive gasses and smoke release are understood by those involved in the specification and design process, and in these scenarios ‘Halogen-free’, ‘Flame-retardant’ and ‘Low-smoke’ are required. For these cases, cable manufacturers need to use non-halogenated materials, mostly with flame retarding fillers. While effective in retarding flame propagation, some of these fillers can negatively affect the polymer by reducing electrical performance or by affecting mechanical properties and water resistance. For this reason, many non-halogen flame retardant additives are used only in the cable sheath. Halogen-free flame-retardant cables often use unfilled polymers like Polyethylene (PE/ XLPE) or EPR for the insulation, which have good electric and mechanical properties but may not be very flame retardant.
The best flame-retardant cables are often halogenated because both the insulation and outer sheath are flame retardant. When we need Halogen-free cables, we find it is frequently only the outer sheath that is flame retardant and the inner insulation is not. This has significance because while cables with a flame-retardant outer sheath may pass flame retardance tests with an external flame source, the same cables when subjected to high overload or prolonged short circuits have proved, both in practice and in industry tests at universities, to be highly flammable and have started fires.
Worldwide application
In the USA, many building standards do not require halogen free cables. This is not because Americans are not aware of the dangers, rather the approach taken is that: “It is sometimes better to have highly flame-retardant cables which do not propagate fire, than minimally flame-retardant cables which may spread or contribute to a fire”. A small fire with some halogens may be better than a large fire without halogens.
The UK, Europe, ASIA, Australia and many other countries have adopted a different approach, preferring both Halogen-free and Flame-retardant performance. Whilst this seems desirable, the reality can be rather different. In asking for both flame retardant and halogen free properties, cable manufacturers must often compromise between using halogenated materials with high flame retardance, or using non-halogenated materials, which can have reduced flame retardance or compromised cable performance in other areas.
This is not an easy balance for wire and cable and compound manufacturers, but many reputable wire and cable manufacturers do achieve an optimum performance and achieve full standards compliance for their products. The difficulty comes when these quality cable manufacturers must compete in markets where regulation or specification does not mandate third party accreditation and allows producers to self-certify their cables. This makes any desk-top comparison or assessment of cable quality between suppliers virtually impossible.
Non-compliant cables
In Australia, manufacturers and importers were previously allowed to self-certify electric building wire, for fixed installation in buildings. This resulted in some manufacturers and importers bringing into the market low price, low quality products, which were claimed to comply. On inspection it was found that they did in fact, not conform with local standards. This situation initiated mandatory Government recalls of wire and cable from resellers and contractors, as well as ordering the removal and replacement of installed non-compliant wire and cable from domestic, industrial and commercial buildings.
This situation is now causing huge financial and legal problems for the industry as building owners, operators, and contractors are being held liable under law for:
- Rectification orders and other sanctions
- Prosecution, fines and potential loss of licences, if the sanctions are ignored
- Financial liability in case of property damage, injuries or loss of life
Between 2010 and 2013, 3.9 million meters of non-compliant cable was imported into Australia. Currently 403km have been recovered from warehouses, 283km installed have been remediated, 787km are planned for remediation but over 2,400km are still installed, much in unknown buildings.
Australian regulators have since implemented mandatory one-off testing for building wire, but many other cables used in buildings are still self-certified, including critical Fire-Resistant cables.
For this reason, it is imperative that the cables you choose, for your projects, fully meet the requirements of all cable construction and performance standards.
In addition to the potential fire or shock risk, it is highly unlikely insurance companies will insure or honour their obligations to policies for domestic, industrial and commercial buildings where non-compliant cables are installed.
Of course, Australia and New Zealand are not the only countries exposed to non-compliant and dangerous wire and cable products. The UK has had similar issues, and in 2010, 11 million metres of cable was recalled.
Conclusion
In today’s world of free trade agreements, instant communication and fast, inexpensive transportation of goods, competition for supply of building products around the world has become truly international. Unfortunately, regulation has remained largely national and the effectiveness of national laws across international borders is complex at least.
Many contractors under extreme competitive pressure, have been taking advantage of this internationalism of supply, by chasing ever more competitive offers for building products from around the world. This has led to producers in some less regulated countries, making products which claim compliance but in practice or production fail to meet or maintain that compliance. Whilst excluding the many cases of falsification of test reports and documents, even good-intentioned producers without the pre-requisite management systems and controls can struggle or fail to maintain consistent quality.
Where electric cables are required for fixed installation in buildings safety must always be the priority. This is why building regulations are mandated by governments and product compliance with national and international standards are often required by law.
In most countries, an official product recall means that the cost and liability for remedial process of removal and replacement falls on the builder, installing contractor and/or project owner. This may also have ramifications for designers and consultants where it can be shown ‘reasonable skill and care’ may not have been applied.
The question for authorities, owners, operators, consultants, designers, contractors and installers today must be:
“What can I do to prevent the risks of non-compliant products being used on my projects or in my equipment?”
The answer for wire and cable products is simply to demand third-party product accreditation for all Low and Medium Voltage fixed wire and cable products. The BASEC PCR & CPR approvals provide the best possible assurance, that cables purchased and installed will consistently meet or exceed all the required product manufacturing standards and operational performance requirements.
What will a third-party product certification do for you? As an authority, designer, contractor or end-user:
When you demand third party product certification (PCR) you ensure that all of the wire and cable purchased and installed in your projects, will fully and consistently meet all criteria of the required production and performance standards. It will cost you nothing, while ensuring non-compliant wire and cable is excluded.
Third-party accreditation means you do not need to rely upon and accept manufacturer or distributor provided test reports. You can be sure that the manufacturer and the products supplied are both valid and continuously monitored so that the first meters installed are as compliant and current as the last meters installed. With a BASEC accreditation, you can check the status of all approved manufacturing companies, their production plant and products on our online, homepage search service at www.basec.org.uk
As a wire and cable manufacturer:
Product Certification Requirement (PCR) tells your customers that you are a world class, responsible and quality manufacturer of wire and cable. It tells them they can rely on you for consistent quality, of both product and performance. It demonstrates that your company and manufacturing process continuously improve and adopt the world’s best practice.
You increase your competitive advantage with third party product certification, by differentiating your products from the many cheap competitors. Product certification defends your:
- Cable price
- Value proposition to customers
- Reinforces your company image in the market
- Differentiates you from many cheap competitors and
- Positions you as a technology leader
Compliance to both the BASEC PCR and the European Union mandatory Construction Product Regulation (CPR) gives you access to major projects and markets were specifications and regulations request evidence of third-party certified cables.
Contact BASEC today at marketing@basec.org.uk to organise an on-site educational seminar, or to schedule an online presentation. These are provided free of charge to industry organisations, manufacturers, authorities and consultants.
Link to published version on BASEC website
About the Author
This post was uploaded by Mark Seton.
