Help with identifying lighting circuit

[Sard]

Hi,

I'm looking at changing my current light fittings and have been comfortable with my other rooms that have had a single switch loop in wiring setup, but this one has me stumped.

The current setup is as follows: 2 ceiling roses that are controlled by 2 light switches on a single circuit i.e. turn on an off in unison. To me it looks like a form of loop in wiring, but I'm having a hard time figuring out which wires are neutral and which are switched live. I stupidly forgot to take not of how the previous fittings were wired, hence I would really appreciate if someone could look have a quick look at the attached photos and give me a steer. Also it's my first time working with 3 core cables, so it's a bit of a learning curve for me

 

[Sard]

Quick update, I've managed to wire a downlight to one of the ceiling roses, with both switches working as expected. However, the second ceiling rose (picture attached ) is giving me a few issues. When I wire up another downlight, it's on permanently whilst the other one turns on and off with the switches. I'm wondering if I could just remove the wiring between the first and second ceiling rose and wire my downlights in series as I have done in my other rooms? I've tested this by directly attaching a second downlight to the first and it works just fine.

 

[EFLImpudence]

At the light that isn't working properly some of the wires must have been not connected to the light and separately terminated.

Can you remember which?

 

[Sard]

My gut feeling is that it's the yellow wire in the photo, when I detached the previous fitting I noticed the red wires were together and the blue & black wires were together.

 

[EFLImpudence]

Well, from this picture of the light that is working:

Have you connected them as they appear in the picture?
Blue and black together and yellow and other black together.

Assuming the Red, Yellow and Blue at both lights is the same cable, this should be tested and verified.
It would appear that the wires at the other light are:

Yellow - (switched) live, and
Blue - neutral, which is all you need - plus earth of course.

The red is connected to the supply live at the first light which is probably why the light won't go out.
The purpose of the other red and black cannot be determined from the picture.
These three wires should be terminated in separate blocks until you can test to see if they do anything.

 

[Sard]

Well, from this picture of the light that is working:

Have you connected them as they appear in the picture?
Blue and black together and yellow and other black together.

Yes, just as described and shown in the photo.

Assuming the Red, Yellow and Blue at both lights is the same cable, this should be tested and verified.
It would appear that the wires at the other light are:

Yellow - (switched) live, and
Blue - neutral, which is all you need - plus earth of course.

The red is connected to the supply live at the first light which is probably why the light won't go out.
The purpose of the other red and black cannot be determined from the picture.
These three wires should be terminated in separate blocks until you can test to see if they do anything.

Thank you for the guidance. I tried just that by seperating the red wires and black wire and the second light is now working perfectly. However, lights in two adjacent rooms are now no longer working. I've swapped light switches over in one of the rooms and that hasn't resolved anything, so I'm assuming the red wires and black have a part to play in this? Light in other adjacent rooms appear to work ok and if it helps, my intuition tells me the lights closest to the CU work and the two rooms without working lights are the last lights on this circuit. Hope that helps?

 

[EFLImpudence]

In that case connect the red to the other red and

the black to the blue.

 

[Sard]

In that case connect the red to the other red and

the black to the blue.

That worked a treat. Thank you ever so much. I'm really grateful for your help and patience with my questions. Could I buy you a cold beer via paypal?

 

[EFLImpudence]

Thank you for the offer but that's not necessary.

 

[winston1]

and wire my downlights in series as I have done in my other rooms? I've tested this by directly attaching a second downlight to the first and it works just fine.

No you haven't. They would be very dim if you wired them in series.

 

[Sard]

By series, I mean one downlight attached to the next and so forth. Maybe series is not the right term?

 

[Sard]

Just using this thread to ask another quick question.

I'm planning to add another light to the existing circuit that will run off a seperate dimmer module. My understanding is that I can run a 1mm2 cable from the existing circuit to the dimmer and connect live to the COM terminal and then run another 1mm2 cable to the light fitting with the live from this cable wired into L1 on the dimmer and join the neutral and earth up with the wire coming in from the circuit, so that neutral and earth from the light fitting have continuity back to the circuit.

I'd appreciate if I could get some validation on this.

 

[terryplumb]

At the switch housing ,the two neutrals would go together in an insulated terminal block . They do not connect to the switch !! The two earth's would connect to each other ,that can be done at an earth terminal on the dimmer ( if indeed it has an earth terminal) or if it does not ,in a second insulated terminal block. With regard to running cables( twin and earth ) ,from circuit to switch and from switch to light fitting, yes you need to do that .

 

[Sard]

At the switch housing ,the two neutrals would go together in an insulated terminal block . They do not connect to the switch !! The two earth's would connect to each other ,that can be done at an earth terminal on the dimmer ( if indeed it has an earth terminal) or if it does not ,in a second insulated terminal block. With regard to running cables( twin and earth ) ,from circuit to switch and from switch to light fitting, yes you need to do that .

Thank you. That's exactly what I meant