Loop-in wiring light problems

[sparkwright]

Are you able to identify at the light with 4 cables; which cable goes to the switch, and which cable goes to other light in the same room?

 

[hdp]

The switch live cable is marked. I thought I knew the cable going to the next light but it must be wrong given the results. Hopefully the multimetre will resolve this when I can test which is not a live wire.

 

[PrenticeBoyofDerry]

If you disconnect all cables, you should only have one cable that is permanently live.
Then if you can identify the switch lives, it should be plain sailing.

 

[hdp]

So I have 2 S/L wires?

diagram linked in earlier post still only has 3 cables shown so not clear how I wire up 4th

 

[JohnW2]

If you disconnect all cables, you should only have one cable that is permanently live.

True, but are you suggesting that live testing should be undertaken to determine which?

In passing, can you (or anyone) make sense of what is being reported, namely:

Both lights are controlled by the same switches (there are 3 in the room) and both lights should come on at same time. Currently the way it's wired (if I attach both lights) one comes on while the other is off and switching any of the switches turns the one off and the other on.

I'm struggling to understand how one could get that functionality without some very strange wiring.

Kind Regards, John

 

[sparkwright]

So I have 2 S/L wires?

diagram linked in earlier post still only has 3 cables shown so not clear how I wire up 4th

No.

You should have one cable live and neutral in.
One cable live and neutral to next room.
One cable to switch.
One cable to other light in the same room.

You know the switch wire. You only need to verify the cable to the other light in the same room.

 

[sparkwright]

Hi



The first has 4 cables. I've tried following the diagram in the link below as a guide to how to wire it, but its not worked.

http://www.diy.com/diy/jsp/bq/templ...ow_to/fix_ceiling_light/fix_ceiling_light.jsp

Your wiring should be like the second diagram, only with an extra fourth cable. This fourth cable goes to the other light in the same room.

The fourth cable gets connected to the 'flex to light' terminals (switched live and neutral).

This ensures both lights come on together.

 

[EFLImpudence]

Are we looking at the same diagrams?

Your wiring should be like the second diagram, only with an extra fourth cable. This fourth cable goes to the other light in the same room.

Shouldn't that be the FIRST diagram?

The fourth cable gets connected to the 'flex to light' terminals (switched live and neutral).

Both diagrams have four cables.

This ensures both lights come on together.

Edit - I now see that there are other diagrams.
I was looking in the 'adding an extra pendant' section.

 

[JohnW2]

People are making suggestions based on the assumption that the wiring is conventional, but it still seems to me that something odd must be going on with the wiring. We have been told:

The second light in the room was simple; there is one cable from the ceiling and I could directly wire into the new junction. The first has 4 cables.

and..

Both lights are controlled by the same switches (there are 3 in the room) and both lights should come on at same time. Currently the way it's wired (if I attach both lights) one comes on while the other is off and switching any of the switches turns the one off and the other on.

If (as should be the case), there is just a single cable connecting the second ('slave') light to the first, then I can't see how the described behaviour could happen unless there were (obviously 'unconventionally') three (or more!) cores coming from the switches to the 'main' ceiling rose. Otherwise, how on earth could there be power being supplied to the second ('slave') light when the first light was 'off', but not if the first light was 'on'? ... or am I missing something 'obvious'?

Kind Regards, John

 

[hdp]

I've identified the wires:

I have 1 main supply wire - test using multimeter on AC setting
I have 2 wires giving residence on multimeter. One was labeled the switch live with brown tape, I think the other goes to next room.
I have 1 wire showing neither reading which I believe is the wire to the second light in room.

Wired up as advised. Same problem as reported originally with one on one off.

Really appreciate some help!

 

[EFLImpudence]

I've identified the wires:

Good

I have 1 main supply wire - test using multimeter on AC setting

Right.

I have 2 wires giving residence on multimeter. One was labeled the switch live with brown tape, I think the other goes to next room.

So, one not identified, then.

I have 1 wire showing neither reading which I believe is the wire to the second light in room.

So, a second not identified, then.

Wired up as advised. Same problem as reported originally with one on one off.

Not, though as originally wired when it worked.

Really appreciate some help!

I'm afraid the only way is for you to learn and understand how the circuit works and how to test to be certain - or an electrician.

 

[Taylortwocities]

I have 2 wires giving residence on multimeter. One was labeled the switch live with brown tape,
!

Its RESISTANCE. Measured on the ohms setting.

If it IS the switch wire, then that resistance will go on and off when you toggle the light switch.

I think the other goes to next room.
!

Coule be, or it could be the feed to the other light. If you put a lamp in that lamp holder you should see a resistance, The resistance should go away if you take the lamp out.


By a process of elimination you will then have identified all four cables. It should then be a simple job of wiring it up as described above.

 

[hdp]

Thanks all for helpful tips

All fixed. Switch live was marked wrong. They marked the 2nd light cables neutral with brown tape. Argggggghhhhhh!