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The use of SY cable in Lift installations

David Alcock

Hi,

I've noticed recently that lift companies tend to use SY cable for the supply cable from the Mian isolator (provided by main MEP contractor  under BS7671) to the lift control panel main intake connection of the lift

I know Lifts are not covered by BS7671, but I'm aware that these cable types are designed for use in Control environments and are discouraged in BS7671 for power circuits/Fixed installations

when questioned lift companies just issue data sheets for the said cable, spouting VDE compliance, although they are not manufactured to any manufacturing standard, how do they certify the installation when every way you look points to them not to be used as power cables? even if in lift installations? 

:The cable manufacturers even state on their data sheet they are "control cables" with mech protection 

Regards

  • How will you proceed with this ? Will you have the cable replaced as it’s unsuitable and does not comply with UK standards?

  • in reply to Sparkingchip

    Thanks, yes i agree, and nobody should be using these cables, until such time they are approved or made to  standard with relevant data to back the cable up to allow accurate calculations to be undertaken, or its their risk when it fails

  • in reply to lyledunn

    Lyledunn

    I cant remember back in 1987 when i took my AM2, but back in them days SY was made in the UK to  UK standards with better insulation etc, its not now or made to any worldwide standards and has inferior insulation, no UV protection etc, also how do you size the cable as there are no cable factors you can use! I'm guessing most people just use the BS7671 tables, but they are for different cables made to a standard

  • Since I can remember, SY cable installation has been included in the AM2, which is the national end point assessment for electricians seeking recognition in the UK. At some point, someone must have pointed out the difficulty with 7671 compliance and so now the departure section of the EIC that the candidate completes is already pre-filled to indicate the non-conformity.

    Because SY is used in the AM2, it is also used by colleges and training centres in preparing candidates for the assessment, so you really couldn’t blame operatives for using it without question.

    As AJ indicates, it is time it was sorted. 

  • youtube.com/.../7R9ZBF4LxuQ

  • Ditto for air-con installations.

    I guess the real problem isn't the cables as such, but the lack of a comprehensive BS or EN standard for them.

    It seems that SY/CY/YY cables are commonly used for fixed wiring in Germany etc - and presumably accepted as "correct", if only by virtue of their local national standards, so I suspect the real physical problems from using these cables are minimal. Presuming they've come from a decent manufacturer at least (and given one or two instances in the last few years of BASEC registered manufacturers producing sub-standard cables) documented compliance with standards alone can't be seen as a total guarantee.

    It is interesting how much variation there is of acceptable cable types between countries with pretty much identical laws of physics. Most of the rest of Europe would be horrified by our T&E whose stiff conductors don't always make good contact in cage clamp terminals and where the c.p.c. is both undersized and under protected.

    I reckon it's about time the standards committees pulled their fingers out and produced a suitable standard, so we would know where we stand with them, officially,

       - Andy.

  • Hi David. As an electrical contractor, I frequently handle the installation of supply lines for lift systems, extending from the substation to the lift machine room, where we terminate into an isolator. Subsequently, the lift engineer connects the SY cable from the isolator to the lift control panel. Our certification only covers up to the line side of the isolator. But is using this cable a problem? BS 7671 does permit If the specifier or designer ensures an equivalent degree of safety as would be achieved with a British standard cable.
    -Andrew

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