SWA Colour codes

Discussion in 'Electricians' Talk' started by Mike58, Jul 10, 2018.

  1. Mike58

    Mike58 New Member

    Brown - Live
    Grey (sleeved Blue) - Neutral
    Black (sleeved Gn/Y) - Earth

    I believe that is the "usual" way rather than Bn-Live, Bk-Neutral, Gy-Earth. However, is there a "standard" which defines this or is it just accepted, best practice?

    Just sorting out an install where there may be two differing implementations and want to harmonise it.
  2. Bazza

    Bazza Well-Known Member

    Cable cores do not know what they are. They are just colours. It is up to you to denote what they are, what they do and mark them approprietely. When the colours changed, the IET put out guidance which is, as you say:
    The reason was to drive people away from using black as neutral, and avoid confusion. So that worked, didn't it.

    The convention is
    Line = brown
    Neutral = blue
    earth = green/yellow


    you must colour sleeve/mark any conductors of varying colours to confirm their use to the next guy/girl along.

    So. Use the grey as neutral, but it must be sleeved/marked with blue
    and use the black as earth, but it needs green/yellow sleeve.

    If you use a colour other than brown for a live function (eg a switched live in a lighting circuit) this conductor should be tagged with a brown marker.

    Dr Bodgit likes this.
  3. JP.

    JP. Screwfix Select

    It cant be that simple Bazz surely?
  4. Dr Bodgit

    Dr Bodgit Well-Known Member

    This is the key thing I recall when looking into this topic.

    It really is that simples :D

    unless of course you're a DIYer asking about how to run a cable to his shed/shack at t'other end of t'garden.
  5. JP.

    JP. Screwfix Select

    It really is simple then by jove..:)
  6. Dr Bodgit

    Dr Bodgit Well-Known Member

  7. seneca

    seneca Screwfix Select

    It really is JP!
  8. Pollowick

    Pollowick Well-Known Member

    No one has actually answered the OPs question as to whether there is a standard, except for Bazza's comment about IET guidance. I do not know the answer either, so is it just best/accepted practice based on the IET recommendations?
  9. dobbie

    dobbie Well-Known Member

    In the old colours red,yellow and blue,yellow was always used as the earth, oversleeved green then green and yellow.Blue was used as the neutral.

    Although the IEE issued guidelines about brown,black and grey, the logical and sensible thing to do was make black earth oversleeved and grey neutral oversleeved
  10. Dr Bodgit

    Dr Bodgit Well-Known Member

    Its an accepted best practice standard :)

    Or put it another way - if you, a professional spark, fitted an SWA with the black as the neutral with appropriate sleeving, would it still be "OK"? Would you still be able to sign it off?
  11. dobbie

    dobbie Well-Known Member

    That is the proper way to do it,sleeved green and yellow.
  12. Dr Bodgit

    Dr Bodgit Well-Known Member

    I corrected myself just after you posted...

    Or put it another way - if you, a professional spark, fitted an SWA with the black as the neutral with appropriate sleeving, would it still be "OK"? Would you still be able to sign it off?
  13. dobbie

    dobbie Well-Known Member

    I wouldn't do it.
  14. Dr Bodgit

    Dr Bodgit Well-Known Member

    I'd say it's more than guidance then, but I'm not getting into a debate as to whether that constitutes it being a standard. More standard than guidance I'd say.

    No different in my eyes to using standard T&E but swapping so brown-neutral and blue-live with appropriate blue/brown sleeving. Such practice would at least be frowned upon.

    Or using old black/red T&E in a new install.
  15. JP.

    JP. Screwfix Select

    Cheers Sen - at last something which is simple, strewth I cant believe it..:)
  16. Bazza

    Bazza Well-Known Member

    The on-site guide Table 11b provides GUIDANCE as to the old/new colour equivalents for both single and three phase whirring.
    I'm not going to recite the whole thing, but it effectively says what I wrote above.
  17. Dr Bodgit

    Dr Bodgit Well-Known Member

    One mans guidance is another mans standard.
  18. spinlondon

    spinlondon Well-Known Member

    It’s not the IET’s guidance, far from it.
    It’s the NICEIC’s guidance.
  19. unphased

    unphased Screwfix Select

    You wouldn't believe how many times I find the black being used as neutral, contrary to the recommendations and published advice. What you forget is many electricians don't read anything. They work solely by what their mate tells them and believe everything they are told, never questioning anything by checking it out for themselves. To these types it is usual to use the black as neutral because that's what it used to be. The logic there is typical of these idiots. I lose my patience with it all. You arrive to do a job where these morons have been and you always have to work against your better knowledge.
  20. spinlondon

    spinlondon Well-Known Member

    There is no published guidance or Regulations regarding this.
    The NICEIC advise a particular colour because they want to de-neutralise the black.
    Sounds like a good idea, but really there is no evidence to suggest that it is.
    The IET don’t care what colour is used, as long as it’s not a single core G/Y and the terminations are marked appropriately.

    Whenever I go on a new site, I always try to remember to ask which colour is being used for earth. Occasionally I get told it’s G/Y.
    As to whether it’s black or grey, depends.

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