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Ceiling Light - Do I need to connect the earth?

Discussion in 'Electrics UK' started by Sevro, 5 Oct 2021.

  1. Sevro

    Sevro

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    Hello, so last night I went to switch out a new ceiling light and was very confused when I saw there was no place for the earth to fit in to.

    I've been reading up and I take it my lamp is double insulated as it has the two squares? It is made of metal but the rose is plastic.

    So my question is what do I do with the loose earth cable, is it dangerous just dangling about near the other wires not hooked up? Do I just shove it back in the ceiling ?

    Any help would be really appreciated! Thanks PXL_20211004_203045395.jpg PXL_20211004_204927024.jpg PXL_20211005_174017809.jpg PXL_20211004_205316812.jpg
     
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  3. rich8000uk

    rich8000uk

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    The double squared box symbol means it's double insulated and does not get earthed. The now spare earth wire should be sleaved (the green and yellow in the picture will be fine), and terminated (ie a connector put on the end) so it can't touch a live terminal.
     
  4. Sevro

    Sevro

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    Ok great, thanks so much for the help!
     
  5. 333rocky333

    333rocky333

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    Though technically, i think its only classed as DI if the wires are encased in that stupid terminal case, which is physically impossible unless you snip off the earth.
    Personally i would forget the DI on the top section and lug the earth onto the metal bracket and use normal connecters or wagos.
    The thread and the metal will then be safely earthed in the event of a short within the housing.
    The lower section will still be DI and isolated by the flex
     
  6. plugwash

    plugwash

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    Equipment is divided into classes depending on how protection from electric shock is achieved.

    Class 0: Protection by basic insulation only. No longer allowed in most western countries, not "single fault safe".
    Class 1: Protection by the combination of basic insulation with earthing.
    Class 2: Protection by Double (basic plus supplementary) or reinforced insulation.

    Cables are effectively double insulated (though the cable standards don't use that terminology), the insulation on the cores serves as basic insulation and the sheath serves as supplementary insulation.

    There seems to be a problem in the lighting market with manufactures producing equipment that is nominally class 2 and no doubt under laboratory conditions passes the requirements, but that is difficult to install in a way that maintains the double insulation.

    I suspect the reason there hasn't been a big scandal about this is that the risk from a ceiling mounted light fitting is rather low, even if it is "class 0". Still it creates a problem for those of us who want to do a "proper job" of installing said fittings.

    The fitting is designed to achive double insulation by enclosing the single insulated live and neutral conductors within the terminal box. You are lucky in that you only have a single cable, so it's probablly possible to achive this, but it will likely require cutting the live and neutral conductors rather short and either cutting off the earth or maybe bending it back out of the terminal box and sleeving/terminating it separately.

    You could possibly argue that the fitting meets double insulation even without said terminal box, after all the outer case of the top part is plastic, the only issue would by the possibility of access from the back to the metal bracket or it's fixing screws.

    Or as 333rocky333 suggests you could attatch an earth to the metal bracket and make the top part class 1.
     
  7. RandomGrinch

    RandomGrinch

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  8. Sevro

    Sevro

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    Thank you all so much for the input! I think I will try to terminate the earth wire as that seems the easiest to me.

    I was also looking at connectors on screwfix to terminate, how much does the Amp rating mater when choosing one?
     
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