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Thread: Wrong to use black / red wire in new build

  1. #11
    Site Caretaker Dave A's Avatar
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    Quote Originally Posted by Derlyn View Post
    I also use the green/yellow conductor in cabtyre for the return from day/night sensors ( convenient ) but I slip a peace of red heatshrink over the ends to make it legal.

    Peace out .. Derek
    Quote Originally Posted by ians View Post
    Reading note 6.3.3.2

    2) an earth continuity conductor shall be identified by the bi-colour
    green/yellow only, or by being bare. Green/yellow insulated
    conductors shall NOT be used as live conductors under any
    circumstances
    Quote Originally Posted by Derlyn View Post
    4) the colours may be applied at the ends of the conductor (of a
    multicore cable)
    by means of durable colour marking (e.g. insulating
    sleeves or by electrical insulating tape wound more than once around
    the conductor)

    Quite legal when the conductor is in a multicore cable such as cabtyre.

    Peace out ... Derek
    Derek, I gently suggest you have not given the term "under any circumstances" its proper due.

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    Good morning to you, Dave. Happy weekend.
    The lawn is waiting for me to be mowed after some good rains, but first onto more serious stuff.

    Interesting subject which I think deserves some more debate and discussion.

    There are reasons why certain regulations have been put in place.
    I am one of those who not only wants to know what the regulations say, but also the reason/s behind such regulation.

    As far as conductor identification is concerned, why is special mention made of multicore cables ?

    My take is as follows:

    There are only 2 sections of a multicore cable where conductor identification is of importance ie. the ends where the conductors protrude.
    What happens along the length of the cable is of little importance as the conductors are 1) invisible and 2) not easily accessible.
    The same cannot be said for a single conductor that is both visible and accessible along it's entire length.

    How many times have I come across a single phase DB supplied with a 3 core cable where the red is used for supply, blue for neutral and white for earth.
    What would now be the right approach assuming that the cross section of the conductors are sufficient for the intended purpose ? To replace the cable ? No.
    1. The blue conductor is made black with either tape or heatshrink for the neutral and
    2. The white conductor is made green/yellow as above for the earth.
    Acceptable ? I would say "yes" as per 6.3.3.2(4)

    Now we have a situation.

    The earth conductor, even although the ends are clearly identified green/yellow, is actually white. Is this of importance ? I would say "No" because it cannot be seen and is not easily accessible. Likewise, the neutral, black at the ends, but blue inside the cable, according to regs is acceptable.

    This is my understanding of why a clear distinction is made in the regulations between identification of single conductors and those housed in multicore cables.

    This is also the reason that I, with a clear conscience, use cabtyre for day/night sensors after changing the colour of the green conductor protruding from the cable to red by using heatshrink.

    Maybe some of the other toppies can comment.

    BTW I do agree that single green/yellow conductors not forming part of a multicore cable should under NO circumstances be used as live conductors.

    Peace out ... Derek
    Last edited by Derlyn; 21-Nov-20 at 12:47 PM.

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    Hi

    Don't understand the confusion - As Dave stated above it is pretty clear by using the words " Shall NOT " and " under no circumstances" - The NOT is in capital letters and bold in the regulation.

    I see the multi core cable , like a 7 core armour cable , which does not come at all with a Green/yellow being marked at the ends to show the earth - In the old days a multi core armour cable used to come with all the wires black and numbered.
    To take a green yellow and marked it as a phase cannot be legal especially since it is emphatically stated that it " Shall NOT be used under any circumstance " - Only having a 3 core piece of cabtyre lying loose in the bakkie cannot change the " under any circumstances " clause even if it is marked.

    I believe that an AIA would fail the installation.

  4. #14
    Site Caretaker Dave A's Avatar
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    The way I understand interpretation of the code is that we need to ensure that what we do complies with all the applicable clauses. Quite often where I see an argument about a "grey" area, if one looks closely there has been an interpretation such that an applicable clause has been ignored, or there is a claim that one clause trumps another.

    The classic example is earthing of electrical equipment -

    6.12.3.1 The following conductive parts shall be earthed:

    e) earthing terminals of all permanently connected electrical equipment and appliances;

    But despite this some contractors deem they don't have to connect downlighters with earth terminals to earth because -

    6.12.3.2 The following conductive parts do not need to be earthed:

    b) exposed conductive parts of fixed electrical equipment that are:
    1) out of arm's reach from the floor (or walking) level,
    2) out of arm's reach from a structure that is bonded to earth, and
    ...

    If 6.12.3.2 commenced with "Despite the provisions of 6.12.3.1" they would have a case. But reality is the installation needs to comply with both clauses. The solution is simple - electrical equipment with an earth terminal needs to be connected to earth.

    An example of a specific exception is 7.1.5.1 which is very specific -

    7.1.5.1 Except in the case of isolated supplies, an earth continuity conductor shall be connected to the earth terminal of class 1 fixed appliances in a bathroom.

    This, quite clearly, is intended to trump the requirement of 6.12.3.1.e.

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