The last few years have seen a rising negative press towards YY, CY, SY type cables – some in the industry tout that it is some of the main stream British manufacturers that have been actively sponsoring this. Understandably this has been in a push to control imported types of cable, particularly substandard cables coming into the market and therefore potentially damaging reputations.

However with the latest edition (in fact the 18th!) of BS7671 wiring regulations recently coming into force the critical excerpt from the onsite guide offers its strongest advice yet by saying “for the purpose of this guidance publication and ensuring compliance with BS7671 the installation and use of non- standard cables such as SY, CY and YY cables is discouraged.” Note the word discouraged…while this term may not be categorical in nature its sentiment is that the industry should be strongly persuaded to not use these types of products.

The specifics of BS7671

If you dive into the details further (and if you are that way inclined, which we definitely are at Specialist Cable Supplies!), then the actual relevant sections in BS7671 are:-

  • 133.1.1

Every item of equipment shall comply with the appropriate British or Harmonized standard. In the absence of such a standard, reference shall be made to the appropriate International standard or the appropriate standard of another country.

  • 133.1.2

Where there no applicable standards, the item of equipment concerned shall be selected by special agreement between the person specifying the installation and the installer.

  • 133.1.3

Where equipment to be used is not in accordance with regulation 133.1.1 or is used outside the scope of the standard, the designer or other person responsible for specifying the installation shall confirm that the equipment provides at least the same degree of safety as that afforded by the compliance with the regulations. Such use shall be recorded on the appropriate electrical certification.

What does this mean in the market place?

In fact regulations 511.1 and 511.2 also reiterate this standing, so it is with a gladdening heart that we see that many sites are calling for BS standard cables only, without reading the true nature of the regulations or cables used. However, and there is always a ‘however’ or ‘but’ in these situations…the crux of the problem trying to enforce BS7671 ‘BS standard cabling ‘ onto sites, is there are NO relevant BS standards for the types of cable commonly used in applications which need SY or CY etc. Sadly, this is also true of BMS communication cables following Belden style or BUS, KNX, Lutron lighting control cables.  This does not mean they are ‘bad’ cables or do not fall within BS7671, but without the standards being obviously apparent there is no true way of knowing.

The very best approach for complete reassurance is that any reputable manufacture / cable distributor will have all the specification sheets available for their products, stating any European standards if relevant and all electrical characteristics. For example, if you’re using an SY product, the installer / specifier will have shown the cable is fit for use and ‘show same degree of safety’ as per regulation 133.1.3 as outlined above. So, in its simplest terms if a 300 / 500 volt SY is actually stated by the supplier, but it did not meet this the supplier would be in breach of trading standards.

What does the future therefore look like?

We may not have a crystal ball, but it is already very apparent that we are looking into ways of adding further testing and specification i.e. BASEC for these cables to enforce the quality used.  Plus, there is now also a new level of legislation called CPR, which means ALL cables are tested for fire performance. The result of which is an even higher level of reassurance in terms of testing and traceability, alongside which YY, SY and CY cables can be used with agreement in the relevant application and still be in the scope of BS7671.

All very well and good we think, but unfortunately due to commercial pressure on a constant push for cost savings we all do have to be diligent on cables supplied. There are cables and probably will always be cables made to a budget, BUT and it is a big but…not all cables are the same. This is why at Specialist Cable Supplies we do our utmost with duty of care to ensure cables supplied are fit for purpose and our specifications are correct for that purpose. It would be nice to see others following this lead!

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