Cable Standards and Selection

Is this the internal wiring of equipment or fixed installation wiring between different items of equipment? If the former then BS 7671 probably isn't the appropriate standard (black for both poles of power sounds like equipment wiring to me).

If BS 7671 is appropriate then forget 4A4 - that's part of appendix 4 which is just "informative" so isn't part of the definition of the standard (normative). For compliance with standards 133.1 is probably a good start - i.e. comply with a BS or HD or failing that IEC or appropriate standard of another country (but see lots of discussions about the use of SY cable...).

   - Andy.

Hi Andy , thanks for the response.

The spec is for the interconnecting cabling on a skid mounted vacuum pump system. Ive shared the table for guidance on typical cables I would typically expect to see.

But yeah thanks , I'm gonna have to try more bluntly pointing at  133.1.

Kind regards

Chris 

Would other non BS cables be accepted in the UK and signed off  ?
Generally perfectly fine yes, but only if made to an equivalent standard - one offering the same level of insulation/ voltage ratings and conductor cross-section and in the cases of armoured cables, equivalent mechanical robustness, or 'de-scoped' and used in containment, as if soft skinned.

"Sign off" also requires a design authority with sufficient knowledge of other countries standards to make an informed decision. You or whoever this falls to, may end up  with a large folder of datasheets. In general only stuff for the UK market is certified to the BS, so there is far more stuff 'out there' made to other standards.
 
and what are the implications in not following cable recommendations in table 4A3? 
You will need to request access to the cable maker's data, or generic standard data for that type of cable if made to another national or harmonized standard. Some intelligent read-across between cables of similar construction and use of the figures for something similar may be possible unless pushing tight against the maximum ratings.

Mike.

PS as an example for your 2XYRY-fl

try page 30 of this PDF   Nominal 0.6 / 1 kV  XLPE Insulation, steel wire Armour, PVC-Sheath tested to 3500V  reads like it meets or exceeds the spec for SWA for example and has rather lower minimum  temperature, so if you have liquid nitrogen about it may be a better  choice. I'd be pretty happy using that wherever  the same size XPLE low smoke SWA would be accepted

.

For the instrument flex  RE-2X(st)Y  try the Eland data available here.

Again nothing terrible just a PVC insulated and sheathed round cable. Consider rather like arctic flex.

See also Regulations 511.1 (including Notes 1 and 2) and 511.2 (including Note).

There is more paperwork to be done ("justification" as per 511.1 and 511.2) where the cable is not to a British or Harmonized standard (usually numbered "BS", "BS EN", "BS IEC", "BS EN IEC" etc.).

The use of the particular cables (preferably with a reference to the justifications) should be included on the electrical certificates ...

interconnecting cabling on a skid mounted vacuum pump system.

Are we sure this is actually within scope of BS 7671 - rather than perhaps BS EN 60204?

  - Andy.

Very good point Andy , Ill need to do some refreshing on BS EN 60204 tbh.

Hi Andy,

After a bit of searching through my ancient version of BS EN 60204-1 , section 13.7.1 seems to suggest in short that the cables need to be fit for purpose. (btw I am very aware this version is massively out of date)

There is a random note in the section that states cables in such heavy duties refer to relevant national standard. Which is a little cryptic to me.

Have you any thoughts on the overlapping of BS7671 / BS EN 60204-1 . I'm thinking if we can brand the skid as part of a `generator machine` we can relax BS7671 and the pain goes away.

Kind regards

Chris

Have you any thoughts on the overlapping of BS7671 / BS EN 60204-1

Others here will know the intricacies between standards better than me, but as I read it there is no overlap - if BS EN 60204 applies then it's out of scope of BS 7671 - see BS 7671 reg 110.2 (xi).

   - Andy.

AJJewsbury said:

if BS EN 60204 applies then it's out of scope of BS 7671

Absolutely ... except where BS EN 60204-1 refers to IEC 60364 or HD 60364 (i.e. BS 7671)