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Bathroom light trips when switching off

Discussion in 'Electrics UK' started by richje100, 10 Aug 2021.

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  1. richje100

    richje100

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    Hi.
    Fitting a new bathroom in out hour and renewing the light fittings and switches.
    I've replaced the old 1 way pull switch that powered a batten light holder (I know not suitable for bathroom hence the upgrading)
    The pull switch had two wires live and neutral. So I've put the live into the com connector and neutral to L1.
    Tried it and powered the light fine.
    Moved to the light fitting, undone the holder and it had 2 lives to the live terminal and 2 earth's to earth in the plastic holder screwed to ceiling.
    2 neutrals going to the bulb holder. Bare in mind only one connector for L, N and E so had 2 wires into one.

    Rewired new led fitting in same way and comes on but when switching off, trips the light on the main fuse board.
    Something is wrong somewhere. Wondering if it's the led fitting itself yet it lights up?

    Any one can point me in the right direction? I'd rather have a go at things myself but if I have to succumb and get a sparky in I will.
    Thanks.
     
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  3. terryplumb

    terryplumb

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    What exactly trips at the consumer unit (" fuseboard") is it RCD or MCB ?
    Can you show us a pic of wiring connections at light fitting ?
    The switches black conductor is not a neutral by the way.
     
  4. winston1

    winston1

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    No it didn’t. Think would happen if they were live and neutral when you operated the switch. Yes it would connect live to neutral and trip the MCB. Black does not mean neutral. In this case it is switched live.

    Moving on to the light fitting I guess you had 2 permanent lives into a loop terminal and 2 blacks (neutral and switched live) to the lamp terminals. Now again I guess you have wired the new light permanent lives to one terminal and neutral plus switched live to the other. When the switch is off the light is on (with a pull switch you don’t know which is off and which is on). When you operate the switch to on (you presume off) you connect live to neutral via the switched live wire from the switch to the light where it is connected to neutral and trip the MCB.

    If so you need to move the 2 reds together to a terminal strip and connect the 2 blacks separately to the 2 terminals in the light.
     
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  5. securespark

    securespark

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    Do you have a picture of the old fitting before you disconnected the wiring?
     
  6. EFLImpudence

    EFLImpudence

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    upload_2021-8-10_14-57-26.png
     
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  7. ericmark

    ericmark

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    I would guess switched line and neutral mixed up.
     
  8. richje100

    richje100

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    Thanks for the replies.
    This is the original batten light I removed.
    The new light fitting has a terminal block and I followed the same instal as the batten light.... 2 live wires to live, 2 neutral wires to neutral and the 2 earth was already put together with yellow/green sleeve.

    And this is the pic of the new light fitting.

    I'm wondering if it's on a loop and I need a different light fitting?
     

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    Last edited: 10 Aug 2021
  9. terryplumb

    terryplumb

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    The two black wires are neutral and switched live .They do not connect together in a terminal block, they are connected across the lamp.
    On your new fittings terminal block one black goes to the neutral terminal and the other goes into the live terminal .The two red wires must connect together in a sperate insulated connector block or wago ,that does not connect to your new light fitting in any way.
    Hopefully your new fitting will have space to accommodate the additional connector block in its housing.
    The earth conductors connect to earth terminal of course.
     
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  11. EFLImpudence

    EFLImpudence

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    No, you didn't.

    No, it isn't.

    upload_2021-8-10_18-58-28.png
     
  12. richje100

    richje100

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    Thanks for replying.
    If its on a loop will this light fitting still work? And excuse me if it's obvious, the block connector for the 2 reds just terminate in the block?
     
  13. terryplumb

    terryplumb

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    Your new fitting has 3 terminals ,but you need 4. The 4th holds the two reds.
    Is that clear now ?
    The rest of the circuit isnt really an issue.
     
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  14. richje100

    richje100

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    Thank you
     
  15. richje100

    richje100

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    All sorted. Found out which was switch live and all done. Works perfect.
    Appreciate the advice and from others too.
     
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  16. securespark

    securespark

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    Good stuff!
     
  17. winston1

    winston1

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    So exactly as I guessed in my post number 3 which you clearly did not read.
     
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