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How many CPCs in a metal backbox?

Discussion in 'Electrics UK' started by aoused, 29 Jul 2019.

  1. aoused

    aoused

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    Hello,

    I am going to make a small modification to my new build electrics. In the downstairs hallway I have a 2-gang switch. Gang 1 controls outdoor light, gang 2 controls upstairs and downstairs light (further two switches upstairs do same).

    Neutrals are at the switch.

    Downstairs pendant is paralleled off of upstairs pendant. Gang 2 is fed with a piece of three core from the upstairs switch.

    I'm going to replace the 2-gang with a 3-gang so I have outdoor light, downstairs, upstairs. The only drawback is that I won't be able to turn downstairs on from upstairs but I can live with this as I don't want to run a new piece of three core.

    To accomplish this, I will be running a new piece of 1mm from the downstairs switch to the downstairs pendant. I'll disconnect the run between both lights at both ends and Wago it off in the ceiling void for good measure.

    So my question - how many CPCs (1mm) can you have going to a single terminal on the metal backbox? At the moment it's five (upstairs switch, downstairs loop in & out, outdoor light). Can I make it six or should I bring everything into a 7-way Wago and fly out to the back box?
     
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  3. AndyPRK

    AndyPRK

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    Hey, You in Gloucestershire?
     
  4. aoused

    aoused

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    East Mids...
     
  5. EFLImpudence

    EFLImpudence

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    It doesn't matter as long as all are connected satisfactorily.

    A metal switch faceplate would, of course, also require earthing.
     
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  7. RF Lighting

    RF Lighting

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    I reckon about 14 is my record :ROFLMAO:
     
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  8. aoused

    aoused

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    Thanks for this, this is what I'm thinking about and how best to achieve. Plastic face plate (Hager) with no CPC terminal.

    I take it the earths shouldn't be twisted together and I presume doubling over won't be possible.

    Basically if they all go in and survive a tug test, this is acceptable?
     
  9. EFLImpudence

    EFLImpudence

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    They should not and it won't be.

    Yes, of course. They will be a more secure with six than one on its own.
     
  10. sparkwright

    sparkwright

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    Why not make things easy, and put some in a connector block, some in the box terminal, and a wire between?
     
  11. DIYnot Local

    DIYnot Local

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