SY, CY, YY cable

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Di Electric

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Question for all those avid regs readers?

If SY, CY, YY cable doesn't meet any British Standard or EU Harmonized standard, how can it satisfy clause 133.1.1.  If it doesn't (meet either standard), how do I prove compliance with 133.1.3?

some manufacturers say its "generally to..one standard or another"  but generally to, in my world, means it doesn't actually meet the standards 100% and as such it isn't British Standard or EU Harmonized standard approved.

thoughts / help?

Cheers guys

 
SY, CY, YY control cables are not suitable for fixed wiring applications requiring compliance with the requirements set out in BS7671.

 
so if I see it (SY cable) used and there is a signed EIC certificate accompanying the installation...alarm bells should start to ring?

 
If the installation requires the unique properties (good EMI shielding for example) of such a cable and it is suitable for the environment then it is fine to use. However treating as a quick and easy alternative to SWA is not acceptable. 

 
Yes but T&E has BS6004 on it, so hopefully this means it meets this British standard.  SY flex doesn't have anything on it like that so probably doesn't meet a British Standard.  the regs says that any electrical equipment (i assume this includes cable) must meet a British Standard.  I agree it looks like armoured flex - but the braiding in the SY is more for screening rather than mechanical protection as the SY's i have seen have huge gaps in the braiding anyway.  is there anyone from a cable company on here?  

 
SY, CY, YY control cables are not suitable for fixed wiring applications requiring compliance with the requirements set out in BS7671.
as a bit of athought, if someone wired a house in these cables, and terminated the braiding correctly and bonded it all to earth would this not actually provide a safer installation than wiring in FTE????

 
OK the cable is made to DIN 57250 VDE 0250-1.

It is an acceptable wiring material for use in Germany.

Germany use EN 60364 for their wiring standard.

BS7671 is the UK implementation of EN 60364.

Ergo, it is acceptable, as long as it's treated correctly.

It has a class 5 stranded conductor according to IEC 60228.

The insulation is PVC, with a PVC bedding, the overbraid & a PVC sheath.

The braid is braid, not armour.

If it is treated like BS6500 flex, then it's fine, so use the current carrying capacity for BS6500 flex, and installation methods in accordance with BS6500 flex, gland it correctly, earth the braid supply end.

OK, yes I know BS6500 has now been withdrawn, and replaced by EN 50525, but 6500 is easier to type! ;)

Now you will find CY, CY & YY cable being approved to EN50525.

See here:

http://www.clevelandcable.com/products/standards/bs-en-50525211-cable/sy-control-cable-sy-control-flex-bs-en-50525211-and-vde-0250/

As this is a harmonised standard under the LVD, it means one cable for the whole of the EU market, hence the movement by cable manufacturers over to "certifying" their cables to the EN std.

Remember we are still in a state of flux over cable standards as they are only now being harmonised, as a result of the Construction Products Directive.

I will use it, and have used it, but, for specific properties that other cables would not posses, e.g. the class 5 conductor, which is more resistant to vibration.

If you have external influence AH2 or AH3 then a class 5 conductor is more suitable, thus, SWA, 6491x 6004 type cables tend to be unsuitable.

They tend to be class 1 or 2 conductors.

OK, yes you could then say that a 6500 flex has a class 5 conductor, which it may, but, with SY you have an additional layer of the braid and the outer sheath as extra mechanical protection.

Remember that the sheath on a flex to 6500 is not insulation it's a sheath, simply offering mechanical protection for the insulation over the conductors.

Thus the answer to the question, is, if it is selected & installed correctly and complies with EN50525-2-11, then it's fine to use under BS7671.

 
Thanks Sidewinder.  the bottom line of you email is still not convincing me though - does SY cable comply to EN50525-2-11 - every one I have seen says "made to" or "generally to". is DIN 57250 VDE 0250-1 a harmonised standard?  Your Cleveland link even says its "generally to" which I took to mean it is not 100% compliant with BS EN 50525-2-11.

Cable Specification: SY Control Flexible Cable available in sizes 0.75mm to 95mm and manufactured to BS EN 50525-2-11 and VDE 0250. The cable features plain annealed flexible copper conductors, PVC insulated, extruded PVC bedding, galvanised steel wire braid armour, transparent PVC outer sheath. 300/500 volts grade generally to BS EN 50525-2-11 and VDE 0250 class 5.

 
Thinking about that, I would say the generally bit is because it adds on the SY & the clear outer sheath, which are not required under the standard.

 
CY cable complies with BS6500

SY cable complies with VDE0250, BS EN/IEC 60332-1

YY cable complies with VDE 0250, BS EN/IEC 60332-3, BS EN/IEC 60754-1

 
Last edited by a moderator:
Has anyone got access to this ...

http://shop.bsigroup.com/ProductDetail/?pid=000000000030256212

It might contain the definitive answer.

I'll try and see if I can get a look at it next week, if only just to satisfy my own curiosity! :)


Not a lot in -1, but -2 says basically "ask the cable manufacturer if it's OK" if the cable use is not covered by the standard!

To know we would need to have a definitive "HO" code for the cable from the harmonised standard.

 
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