Help with lighting

Discussion in 'Electricians' Talk' started by goldenboy, Dec 12, 2018.

  1. goldenboy

    goldenboy Super Member

    Evening, just after a bit of advice. I am changing over a very weedy old outside light for a new LED one.


    When I took the old light down, on the connector block it had I think two reds from the cables coming in connected to the live brown on the light fitting, one black connecting into nothing, and the earth on the supply connecting to the neutral blue. There is no earth wire on the current light.

    The new light has standard blue, brown and earth.

    What connects up with what?

    Thanks for help.
     
  2. Isitreally

    Isitreally Super Member

    Post a pic up of the wiring as it is.
     
  3. You need an Electrician to trace out what is happening.
    It should not be reconnected until the wiring is sorted,you cannot use the earth as a neutral.
     
  4. goldenboy

    goldenboy Super Member

    Won't allow me to for whatever reason.

    Got two reds on one cable coming in that is connected to the live on the light. On that same cable there is an earth. That is connected to the neutral on the light.

    The other cable has just a single black. That is connected into the block and there is nothing the other side of it.
     
  5. Bazza-spark

    Bazza-spark Screwfix Select

    You need an electrician to check it out. It shouldn't take him long to figure it out and advise you.

    Kind regards
     
  6. goldenboy

    goldenboy Super Member

  7. longboat

    longboat Screwfix Select

    That looks dodgy.
    Has the light suddenly failed to work or has it always been knackered?
    What's inside the switch/fcu that controls it?
     
  8. goldenboy

    goldenboy Super Member

    It works fine. It's just a bit weedy on the light output.
     
  9. joinerjohn1

    joinerjohn1 Screwfix Select

    Looks almost like someone has spurred that off the lighting circuit for the stairs ( 2 way lighting) and have had to borrow the neutral from elsewhere. But have then connected the earth as the neutral. Best to get a sparky in to check it out. You must know one who'll do mates rates ?
     
  10. longboat

    longboat Screwfix Select

    There's a rabbit off ere.
     
  11. Isitreally

    Isitreally Super Member

    Is it on a single switch the other end. ??

    Whats the wiring in the switch like. ??
     
  12. goldenboy

    goldenboy Super Member

    On a three gang switch. I haven't took a look in the switch yet.

    My mate reckons that the reds are a permanent live and switched live. And that the earth might in fact be connected to the neutral the other end.
     
  13. Isitreally

    Isitreally Super Member


    It could be, but without looking in the switch and seeing if the reds are either side of the switch you won't know for sure, the earth almost certainly has been used as the neutral and the black was for something else in a previous life
     
  14. rogerk101

    rogerk101 Screwfix Select

    My money's on your mate's theory too.
    It's a common 'hack' used by some (DIYers and dodgy tradespeople) when they change a regular, switched, outside light, with switched line, neutral and earth to a PIR detector light that requires an additional conductor for the permanent live. They don't understand that these PIR lights are not double earthed, so do require that earth wire. This hack not only voids any warranty but it also voids your insurance if the house burns down, whether or not the fire was caused by it.
     
    goldenboy likes this.
  15. goldenboy

    goldenboy Super Member

    Going to just leave it as is for the moment. Will get it looked at when my mate has time
     
  16. Allsorts

    Allsorts Super Member

    What a job! Right down to the carefully sleeved 'neutral' in green/yellow...
     
    Bazza likes this.
  17. peter palmer

    peter palmer Screwfix Select

    That must just be a simple wiring mistake by a DIYer surely, have you tried the blue with the black to see if it works?

    Strange that its a twin red as a supply though, both must be in the same terminal at the switch. Usually with a twin red at a light fitting there is one or two red/blacks as well for the loop in/out.
     
    tore81 likes this.
  18. Sparkielev

    Sparkielev Screwfix Select

    Previous light may of needed a perm live and a switch live and like peter said could of wired it wrong with the earth and neutral
     
  19. IWANTBLUE

    IWANTBLUE New Member

    This..
     
  20. DaveF

    DaveF Active Member

    Sorry, I didn't read the other replies so forgive me if I am way off. It looks to me like the neutral has just been mistakenly wired in to the earth. The two reds could be switched and non-switched but connected like that the light is on all the time, ignoring any wall switch setting. That would mean that the light has to have a motion detector or dusk to dawn but basically can not be switched off manually. If the light is working via a wall switch and isn't on all the time then the other possibility is the second red is for a second light coming of the same wall switch ( Perhaps at the back of the house once ) but honestly I can't work out why anyone would use a double red cable for that. I mean all in all it doesn't make much sense either way. I would disconnect the reds and find which is the live switched ( which is I assume what you want ) and provided nothing else has failed, blank off that second red. Don't connect what you don't understand.
     

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