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Replacing 2 light switch

Discussion in 'Electrics UK' started by TRIGGER78, 6 Oct 2021.

  1. TRIGGER78

    TRIGGER78

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    Took off faulty dimmer switch.
    Wiring to connect has 1 wire red and 1 wire normal red black yellow already earthed to plastic inner box .
    News switch normal ports 2L1 2L2 and 2 comes.
    Any information greatly appreciated.
     
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  3. JohnD

    JohnD

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    you don't get charged by the word, you know. Punctuation is also free.

    Post a pic of your old switch, including the old connections, please. Include the cables that the individual cores come from.
     
  4. TRIGGER78

    TRIGGER78

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    OK, I wired the 2 reds to L1's a single wire connecting both comm ports, ad put extra wire to black connected to both L2s.

    Only one light came on in back room.
    Regards
     
  5. TRIGGER78

    TRIGGER78

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  6. terryplumb

    terryplumb

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    Did you take pics of original switch/wiring ? Post pics if you did.
    Your new switch is wired incorrectly .do you have any testing equipment, multimeter or twin probe voltage tester?
    The permanent live goes to com.
    L1 on each switch should have only one wire ,being the switched live to each light fitting.
    The short link wire would go between the two com terminals.
     
  7. TRIGGER78

    TRIGGER78

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    Hi Terry no picture of old fitting, broken dimmer switch.I have a voltage tester.The two cables ,one has only one wire red covered in grey coating,the second normal three wire the earth already fixed to plastic box,there was a separate wire which I assume was connected to both comms.
    So if the two reds are connected to both L1's,where does the negative black wire go ?.There is a picture on page.
     
  8. TRIGGER78

    TRIGGER78

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    If the live red goes to com, and the other red to L1 what wire goes in the other L1.
    Regards
     
  9. terryplumb

    terryplumb

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    One of the three conductors is permanently live. Test to establish which it is. Put it in com of one switch with the short bridge wire , and the other end of the bridge wire into the other switches com.
    The remaining two wires ,each into L1 of each switch.
    What voltage testing instrument do you have ?
     
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  11. terryplumb

    terryplumb

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    The black one ! IF ... One of the reds is permanent live .
     
  12. TRIGGER78

    TRIGGER78

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    Just a normal cheap multi tester.
    So it's all right to put remaining wire (black) in the other L1.
     
  13. terryplumb

    terryplumb

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    Which of the three is permanent live ? I suspect it is the red wire coming from the twin and earth cable ( grey sheath with red and black within it )
    If it is ,then yes the black goes to an L1, (and it should have a bit of red sleeve or red tape on it to indicate it is a line conductor)
     
  14. TRIGGER78

    TRIGGER78

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    OK will try and fix tomorrow, will let you know,many thanks for you help
     
  15. terryplumb

    terryplumb

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    Your welcome ,good luck.
     
  16. SUNRAY

    SUNRAY

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    I'm GUESSING it's red to com and com
    other red with grey to L1
    black to other L1
    like this:
    upload_2021-10-6_21-54-22.png
    I've shown the black as blue so it shows up against the switch.

    I'm assuming the red in T&E is perm L.
    If the single red in grey sheath is perm L then swap the reds in my sketch.
     
    Last edited: 6 Oct 2021
  17. SUNRAY

    SUNRAY

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    What isthe brown wire in the middle?
     
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