1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Wiring lights and a Mirror

Discussion in 'Electrics UK' started by spacey3, 8 Feb 2018.

  1. spacey3

    spacey3

    Joined:
    18 Jan 2011
    Messages:
    144
    Thanks Received:
    2
    Location:
    Hampshire
    Country:
    United Kingdom
    I was looking at the wiring that was left by the installer to get my head around how this would work but confused myself even more so I was looking for someone to explain it to me.

    There are two 10w LED downloads in a bathroom, controlled by a switch outside. They are wired in the loft into a junction box. From there the cable comes down to the switch outside, but the cable they have run is a 3core plus earth. Which is were I was puzzled, if this is three cores, how can you then switch the light of the mirror on and off separately?

    Surely you would need to run two cables?
     
  2. Sponsored Links
  3. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,012
    Thanks Received:
    1,307
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    Core 1 = Neutral for Light and Mirror
    Core 2 = Live for Light
    Core 3 = Live for Mirror
     
  4. spacey3

    spacey3

    Joined:
    18 Jan 2011
    Messages:
    144
    Thanks Received:
    2
    Location:
    Hampshire
    Country:
    United Kingdom
    Thanks, for the prompt reply that makes sense to me now :) I was just being dense.
     
  5. spacey3

    spacey3

    Joined:
    18 Jan 2011
    Messages:
    144
    Thanks Received:
    2
    Location:
    Hampshire
    Country:
    United Kingdom
    To clarify, as I read elsewhere on a post here then you would take a small wire from Common on the back of the first switch which came from the 3 core cable and take it across to the common on the second switch.
     
  6. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,012
    Thanks Received:
    1,307
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    That is one way of doing it, there are others. What exactly is the problem? Is something not working? or are you trying to change something? From your original post, I just thought that you wanted to understand how it had been originally installed.
     
  7. spacey3

    spacey3

    Joined:
    18 Jan 2011
    Messages:
    144
    Thanks Received:
    2
    Location:
    Hampshire
    Country:
    United Kingdom
    No, it was that everything was semi wired up from the attic to the new mirror in the bathroom, also the cabinet has an LED light attached to it but that is on a separate junction. So I wanted to tidy things up with WAGO connectors and boxes upstairs, and I took the opportunity to run put the mirror cable into the junction box as it was only half connected for the bathroom lights.

    Originally they had run a 3 core cable down to the switch and wired it up, the light was working so I only wanted to connect the bathroom mirror part also. Hence I asked which core was which as the colours threw me, so it is now wired, tested and working. I just wanted to check that putting a small piece from COM to COM is acceptable.
     
  8. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,012
    Thanks Received:
    1,307
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    It might be, but it also might not. You don't give enough information for anyone to advise. All you mention is a three core cable, at a switch. What are the 3 cores connected to at the other end? What switch? is it an existing switch used for something else? is it a new switch solely for the mirror and the light? We would need details of all of the other wires that are involved in the circuit, not only the one to the switch, but also those that that go to the mirror and light, any junction boxes and where the electrical supply comes from.
     
  9. Sponsored Links
  10. spacey3

    spacey3

    Joined:
    18 Jan 2011
    Messages:
    144
    Thanks Received:
    2
    Location:
    Hampshire
    Country:
    United Kingdom
    The loft has a number of lighting junction boxes. This particular one I was referring to feeds the bathroom and mirror only, plus it has a cable that feeds to the next junction box and one that comes from the previous. I have changed the boxes to be Wago XL and Wago boxes with Wago push fittings for tidiness and placed them on the wall, all I have done is mirror what is already present.

    The new switch with the three core cable sole purpose is for the bathroom light and the mirror only, as I said originally it had a three core cable feed down to it. The lights are two LED downlight JCC FGLED10 which feed from the junction box to the first light and then continue to the second. The mirror feeds from the same junction box, this is an LED mirror light mains powered described as 'fastening set included. LED lighting. for room/outside light switch. Equipped with: 1 lamp. 1x LED / 8W. A-A++. 5700 K (daylight white)'

    So going back to what I asked originally, (basically the colours threw me a little) was which was it went together to independently switch each item on and off, rather than how some do it as both together. While you answered my question perfectly originally, I had to get the COM back into the second switch, hence why I placed a small wire between COM in switch 1 and COM in switch 2.
     
  11. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,012
    Thanks Received:
    1,307
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    If this '3 core cable' is just used for switching purposes, then my original post is probably irrelevant and there won't be a neutral present.

    If it is purely for switching and no neutral is present, the the wires may be. (but who knows if you don't tell us?)

    1. Permanent live supply
    2. Switched live to mirror
    3. Switched live to lamp

    But this is just a guess, because you still haven't answered.
    By this I would be expecting your answer to be along the lines of:

    Wire 1 is [colour] and the other end of it is connected [to the permanent live of the lighting circuit*]
    Wire 2 is [colour] and the other end of it is connected [to the L terminal at the mirror via a connection in a junction box*]
    Wire 2 is [colour] and the other end of it is connected [to the L terminal at the light*]

    *As I don't have a crystal ball, these are just examples the kind of information required, and do not relate to your installation. Yours could well be completely different. So you need to tell us what goes where.
     
  12. spacey3

    spacey3

    Joined:
    18 Jan 2011
    Messages:
    144
    Thanks Received:
    2
    Location:
    Hampshire
    Country:
    United Kingdom
    From the switch Wire 1 Colour is Brown goes to COM on the switch to the Permanent Live of the circuit.
    Wire 2 is Grey and goes to from L1 on the switch to Line in the Junction Box from here it joins the Mirror Line
    Wire 3 Black from L1 of second switch to Line in the Junction Box from here it joins the light Line

    Small brown wire goes from COM to COM on the switch.

    Like this image.

    https://onlineedmeds03.com/double-l...iring-diagram-how-to-wire-a-incredible-ansis/

    It all works, as I said you did actually answer my question originally so I am happy, I just wasn't sure if the wire from Com to Com was acceptable in the same way as that image as I have never seen it done that way.

    If it's still confusing as my explanation isn't clear I can take an image later.
     
  13. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,012
    Thanks Received:
    1,307
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    OK that helps a lot.

    Brown is the permanent live from the lighting circuit and goes to both COM's (via the link between them)
    Grey will be the switched live to the mirror.
    Black will be the switched live to the light.

    No neutral is present. So forget my first post. The mirror and light neutrals will be connected elsewhere, probably directly at the junction box.

    Is there a problem you need help with, or are you just wanting to understand how it works?
     
  14. spacey3

    spacey3

    Joined:
    18 Jan 2011
    Messages:
    144
    Thanks Received:
    2
    Location:
    Hampshire
    Country:
    United Kingdom
    No problem I just wanted to connect the mirror wire up, and as you said I did it in that way and put it back in the Wago junction box. Also partly as I wanted to learn and understand.
     
  15. ban-all-sheds

    ban-all-sheds

    Joined:
    27 Aug 2003
    Messages:
    69,784
    Thanks Received:
    2,857
    Location:
    London
    Country:
    United Kingdom
  16. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Sponsored Links
Loading...

Share This Page