Why sheath the earth wire

Discussion in 'Electricians' Talk' started by im a martian, Dec 14, 2003.

  1. im a martian

    im a martian New Member

    What's the purpose of putting green and yellow sheathing on the earth wire on installations using t&e?

    And why doesn't the cable come with it already sheathed as the live and neutral are?
     
  2. supersparky

    supersparky New Member

    Because it could short against terminals in a fitting, and before anyone says this dont happen, its happened loads to me when moving/inspecting switches, sockets and jn boxes put in by diyers
    if it was sheathed it would take ages to strip the outer sheath
    BR
     
  3. unphased

    unphased Screwfix Select

    its really to identify the earth from the mars...what colour sheath do they have up there?
     
  4. im a martian

    im a martian New Member

    Lol !!! i wondered who'd come out with that one unphased...

    We obviously don't have an earth where i come from, and the system we use is far too complex for you mere Earthling sparkies (or DIYers as we call you)

    ;)
     
  5. Milton Bradley

    Milton Bradley New Member

    The green yellow sleeving is to identify the earth Core as per BS7671:2001..

    However I wish they would make cable with already sleeved earths, as they have done for applicance flexes for years.
     
  6. ban-all-sheds

    ban-all-sheds New Member

    Why?

    What benefit?

    Can you foresee any downsides of that?
     
  7. Milton Bradley

    Milton Bradley New Member

    Better protection for the earth core from mechanical damage or corrosion, as there would be a tightly fitting cover round it - cables do sometimes get installed in damp cellars!
     
  8. supersparky

    supersparky New Member

    ...Then the system would be sealed...using boxes to ipx5...

    BR
     
  9. ban-all-sheds

    ban-all-sheds New Member

    MB - what technique do you use for stripping the sheath from T/E?
     
  10. Milton Bradley

    Milton Bradley New Member

    Strip cable this way, slit the cable lengthways, along

    its centreline, taking care not to damage the earth core

    or the insulation.

    Score round the cable sheath lightly, as to mark the

    surface, but NOT damage the insulation cores, at the

    point you want to strip the cable up to

    Using round nose pliers, tear back the sheath along the

    slit lines, and peel back till you reach the correct

    length of strip, cut off the sheath after bending it to

    one side, then strip the cores with a "stripping plier".
     
  11. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Strip cable this way, slit the cable lengthways,
    along

    its centreline, taking care not to damage the earth
    core

    or the insulation.

    Score round the cable sheath lightly, as to mark the


    surface, but NOT damage the insulation cores, at the


    point you want to strip the cable up to

    Using round nose pliers, tear back the sheath along
    the

    slit lines, and peel back till you reach the correct


    length of strip, cut off the sheath after bending it
    to

    one side, then strip the cores with a "stripping
    plier".


    NO NO NO You Do not ever run a blade down the cable length,just imagine you do this and cut in to the conductors,you also have no more spare,what you do now ? please do not say put some tape round it!

    Only safe way to strip is to use the cpc and pull it back to split the sheath,any other way is way too risky,anyway,we have had this talk b4!
     
  12. That would take too long. I agree with SS. Stripping the cable with the earth is much quicker...
     
  13. Milton Bradley

    Milton Bradley New Member

    Not recommended, as it strains the earth wire, remember it is of a thinner size than the cores, so I would not risk straining /possibly weakening the earth lead unduly.
     
  14. Mind you, I'm in college at the mo and the instructor is teaching us to strip the cable with a blade....

    Cut down the middle about 1/2 an inch then cut along the inside against the cpc so not to cut either the black or red sheath...

    Takes too long so when he's not looking everyone just does it the quick way!
     
  15. supersparky

    supersparky New Member

    streching the earth wire is bullshite, unless you are only stripping an inch, in which case there is strain, cos it has the initian start, once it gets goin.....and what bout the 4mm earth in larger cables...you gunna strech that?
    i know what you mean bout instructor, my bro is doin corse and e said same thing...

    BR
     
  16. supersparky

    supersparky New Member

    initial that should say
     
  17. unphased

    unphased Screwfix Select

    I know its off topic now...but whats the best way of stripping outer sheath on heat resistance flex?..very bad stuff for working with!!
     
  18. ban-all-sheds

    ban-all-sheds New Member

    Whichever technique you use, you'd be stuffed if the cpc was insulated.

    1) With a blade you'd have to be MUCH more careful not to cut too deep.

    2) An insulated CPC would not cut through the sheath if you plan to pull it through that way.
     
  19. Legal Sparrow

    Legal Sparrow New Member

    Wouldn't the lack of sheath on an earth core mean there is more chance a stray nail into a cable will short the earth to live/neutral?
     
  20. supersparky

    supersparky New Member

    you think a piece of pvc will do **** all against a piece of steel? and plus thats a safty feature!!!!! you would have a live nail!!!
    MADNESS

    BR
     

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