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Unknown switch

Discussion in 'Electrics UK' started by J_N30, 22 Dec 2016.

  1. J_N30

    J_N30

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    I moved in to my current house 3 months ago. It had a garage conversion part of which is a utility. In said utility there's 1 ceiling light and 2 2 gang light switches.

    They both do the main light and the one by the back door also does the garden light, however the other switch does nothing at all. It's really bugging me. I've attached a pic, it's the one with a red in L1 and common. Both wires are 240 live regardless of switch position.

    Can anyone suggest what the hell it does??

    Thanks!

    [​IMG]
     
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  3. EFLImpudence

    EFLImpudence

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    How have you measured that?

    If the above is correct then it can't do anything.
     
  4. deadshort

    deadshort

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    Wiring for an extractor fan ?

    DS
     
  5. J_N30

    J_N30

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    Used my multimeter. What's the point in putting a pem live each side?
     
  6. endecotp

    endecotp

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    Measured between where and where, exactly?
    What happens when the switch is in the other position?
    Are both of those wires going into the same cable?
     
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  8. eveares

    eveares

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    Most likley that one red wire is a permanent line (Live) from the supply/feed and the other should be a switched line (Live) going of to somewhere. The two blacks joined together is the mid point between the neutral return from the switched line (live) and the supply/feed.

    Test between the two joined blacks and each of the reds in the switch, in both switch positions and in one switch position your MM will likley indicate no or near 0V.

    Are their any blanked of accessory points hidden away anywhere (inside or outside) what might be a indication of what the switch is or used to be used for. Any round hole sockets or anything else unusual in your house?
     
  9. J_N30

    J_N30

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    Each red is from a different twin and earth. Both blacks in the choc block, netural I've presumed.

    I've tested both reds to black switch on/off 240v on each test.
     
  10. Taylortwocities

    Taylortwocities

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    Otherwise you'd need to trace the cables to see where they go.

    Why not ask the previous owners?
     
  11. J_N30

    J_N30

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    Coincidentally I've emailed the estate agents yesterday to see if they can contact them and ask.
     
  12. DIYnot Local

    DIYnot Local

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