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Ring Main Joint Box

PG
A kitchen worktop twin S,O, is to be relocated horizontally by about 60cm. 

The ring final cct (RFC) is cabled in buried T&E and the galv' steel back-box is flushed into the plaster/brick wall.

The RFC T&E extension cabling will be buried under plaster, covered in plastic capping along the horizontal  prescribed zone. Visually, it would be reasonable for an electrician to be aware that the route may contain cable(s).

The circuit is RCD protected.

The intent is touse insulated crimp and double insulating tape the jointed cables within the existing box to achieve a maintenance free connection, A 2mm thick (fabricated) plate was to be used to cover the back box and provide additional mechanical protection. The box would then be plastered over.


The questions are:-

1. How many would consider the steel plate back box cover a desirable feature or would a simple plastic cover suffice?

2. Should the original back box be left  unearthed?


Thanks in advance.
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  • 0

    2. Should the original back box be left  unearthed?



    The basics of shock protection will still apply - which in effect means you need to provide either earthing or double/reinforced insulation. Unless you're going to make a claim on the (possibly damp) plaster to provide a reliable second layer of insulation (I wouldn't be comfortable doing so) then shock protection needs to be provided at the box. So either double insulate all live conductors within the box (and to my mind a couple of wraps of tape isn't anything like sufficient for that - we should be thinking of something more akin to a cable sheath as a minimum - let alone the problem of the inevitable gaps where the cores emerge from the cable sheath), subsitute both box and lid for insulating versions, or solidly earth both the box and lid (if metallic).


    +1 for the earlier comments about the origianl cable drop being outside of zones if the original socket is removed and/or made invisible.


      - Andy.
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  • 0

    2. Should the original back box be left  unearthed?



    The basics of shock protection will still apply - which in effect means you need to provide either earthing or double/reinforced insulation. Unless you're going to make a claim on the (possibly damp) plaster to provide a reliable second layer of insulation (I wouldn't be comfortable doing so) then shock protection needs to be provided at the box. So either double insulate all live conductors within the box (and to my mind a couple of wraps of tape isn't anything like sufficient for that - we should be thinking of something more akin to a cable sheath as a minimum - let alone the problem of the inevitable gaps where the cores emerge from the cable sheath), subsitute both box and lid for insulating versions, or solidly earth both the box and lid (if metallic).


    +1 for the earlier comments about the origianl cable drop being outside of zones if the original socket is removed and/or made invisible.


      - Andy.
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