Standards interoperability, cable colour codes, Precedence & certification

Good evening folks, still a few familiar names on here so this should be an interesting discussion…,

More and more over the last few years I find myself in product production and the realms of ‘Placing on the market’ electrical equipment .

The sticking points are getting stickier with the advent of new technologies, systems and integrations.

So to dig straight in…

In the case of Solar & Battery installations BS7671 applies.

In the case of Switchgear BS EN 61439 applies.

In the case of machinery and associated control panels BS EN 60204 applies.

If we are building a product it will need certification CE/UKCA etc.

We need to choose the appropriate harmonised standard(s) / Directives etc.

BS7671 it isn’t a product standard and does not apply to ‘products’ that said it still has relevance in that there is little point placing a product on the market that fails to satisfy it’s requirements for installation.

I find cable colours are often a bone of contention with many.

We are all familiar with the standard colour codes in BS7671.

Battery systems are in the main Red - Black - though German vehicle manufacturers now seem to use Brown for negative ground and just about anything for the rest.

MCS now list Solar PV as  Red + White  -

BS EN 60204 has the following colour codes for presumption of compliance.

AC and DC Power Circuits

AC Phase and DC + / - : Black

AC Neutral : Light Blue

AC and DC Control Circuits

AC Live or Neutral via transformer : Red

AC Neutral Light : Blue

DC + – : Blue

Interlocks control circuits supplied from an external power source or remote panel : Orange

Panel Services Colour Coding (multicore)

Colour Coding for Panel Services (Single Core)

AC Live : Orange

AC Neutral : Light Blue

So to the conundrum….

You build a panel (Product) that falls under the machinery directive as a result of its intended use and connected systems, BS EN 60204 supports the use of switchgear within such panels, The panel also has connection for PV array(s) and houses associated sealed battery storage

As a result, there are multiple standards, both harmonised for product certification and otherwise.

Black might be

AC Live of any phase

DC + or -

Red might be 12/24/48v DC +

1500v DC + from a Solar array

Any AC voltage derived from a Transformer etc etc

It quickly becomes apparent that no one standard fits.

If  60204 is chosen as the ‘Primary’ standard that would preclude the use of Red for Battery systems for example.

I realise we can build and certify anything as-long we are willing to certify and accept the risk in the product as the manufacturer.

Most electricians that I talk to just build their own panels and tend not to bother with the certification, however if we are to build and supply to 3rd parties that ‘luxury’ is not an option we can afford. 

From the point of view of installing the panel, we can utilise the outward facing terminals standards, essentially this turns it in to painting by numbers for the installer.

Really I am thinking more along the lines of maintenance and the person(s) who have to work on it in the future. 

How much reliance can we place on documentation and labelling vs conventional knowledge of electricians? 

I remember Paul Skyrme once telling me if they dont know the colour codes they might be better stacking Tesco’s shelves, I understood the sentiment but how far and how much protection would this really offer in a fatality due to mis identification of cabling? 

Apologies if this is a little rambling, it’s a reflection of my mind right now on this subject! 

Thanks

Martyn

Parents
  • Interesting discussion MartynD.  I see your thought logic on this.  Can I also add into the mix UK building regulation which can differ in England, Scotland and Wales.

    A classic example of a BS7671 vs Building Reg.  In a domestic kitchen, what is the minimum distance a socket/accessory can be from the edge of a sink?
    BS7671 does not cover this but other IET guidances/publications offer recommendations
    Building Regs do cover this.

    The answer is 300mm min on the Horizontal plain.

    I do think that BS7671 should have a entry for kitchen accessories even if it just states.   Refer to Current UK build regulation then the reg number eg 433.2.2 

  • Except the BS7671 is not just for the UK - also used in Qatar, Malta etc.

Reply Children
  • BS7671 also does not apply to products, control panels, CE certification etc etc 

  • control panels, CE certification etc etc 

    And also, aspects of wiring between parts of machinery as defined in the Supply of Machinery (Safety) Regulations, which are classed as part of the Machinery. BS 7671 stops at the supply to the machinery.

  • Except the BS7671 is not just for the UK - also used in Qatar, Malta etc.

    And Northern Ireland, where Part P equivalent does not exist!

  • where Part P equivalent does not exist!

    ESQCR (NI) does, though, and this mandates BS 7671 for installations with generators operating in parallel with, or as a switched allternative to, the DNO supply (Regulations 22 and 23), in the same way as Regulations 21 and 22 of ESQCR do for the rest of the UK.

    Generators includes Solar PV and Battery Storage.

    Except the BS7671 is not just for the UK - also used in Qatar, Malta etc.

    Yes, Cyprus too in the EU, as well as a number of countries in the Middle East.