Lighting circuit confusion

[allgermanparts]

Hello all,
First post on a subject I don't really understand but I know it's a killer if I'm not careful etc. OK so we are renovating our other house and I have replaced some ceilings by over boarding and skimming and have made the cardinal sin of not making notes of what cables went where to the switches and ceiling roses etc. I understand basically and I mean very basically how the cables feed in to the rose and on to the next. I have three rooms where there is confusion about what goes where and now follows the reason. The house is very old and it has been knocked about somewhat by the previous dodgy DIY owner. The single bedroom was divided in to two. As a single bedroom it had two ceiling roses ie at each end of the room controlled by a two gang light switch. Nothing on the switch was changed and hence you turn bedroom one light on from inside bedroom one and also turn bedroom two light on from inside bedroom one. Bedroom two was made bigger by knocking through sideways in to a cubby hole/ broom cupboard which had its own light switched on by a bathroom type cord pull switch.. This is also still intact ( but pointless as the room is very small. Still with me? Then read on ..
In bedroom one there are two twin and earth cables one of which is live. I have connected this to the live block in the rose and the black to the neutral block, the earth wire to the earth terminal. The other cable appears to be the switch cable although he has used standard lighting cable not switch cable with two red wires. I have connected the red and black to opposite ( vertically) to the light switch and this light now switches on and off ok) I assume that this means that I have wired this part correctly? .. Now I would have thought that there should be another twin and earth cable that feeds electricity from this rose to the next light in the circuit is this correct? If so perhaps I have lost a cable inside the board and this needs finding or replacing to feed in to the next one? In the next room there are at least three lots of twin and earth and a couple other wires coming out the ceiling rose hole and none of these is live. I assume that there would only be a live if the cable had come out of the previous light fitting and there's no point looking for a live if there's nothing feeding out of the previous light fitting?
I 'd appreciate some sensible and none **** take help please guys and thanks to all in advance. When I have the answer to these I would like to ask some questions regarding what to do with the second light and cord switch in bedroom two.
I apologise for the length of post
Cheers
Jason

 

[EFLImpudence]

//www.diynot.com/wiki/electrics:lighting:lighting_circuit_layouts

 

[AndyPRK]

Yes there should be a 3rd cable unless its the last light, but as you have no power in another room your probably missing a cable.

I would also expect a 4th cable to feed the 2nd light that's controlled by the same switch.

 

[allgermanparts]

I appreciate the useful replies there. I may be back to ask some more questions

 

[allgermanparts]

Yes there should be a 3rd cable unless its the last light, but as you have no power in another room your probably missing a cable.

I would also expect a 4th cable to feed the 2nd light that's controlled by the same switch.

Hi Andy
There was indeed a wire tucked away which I have managed to get out. I have the main bedroom light working and the bathroom although not yet the second bedroom. I have fed the second bedroom rose using the previously elusive cable and this is now live. I have connected a cable from the second bedroom ceiling rose hole to the bathroom am have connected the pull switch. I am 'test ' using a standard ceiling rose to get it working as I wanted to following the diagram I previously used to wire the main bedroom and the bedroom one and bathroom light work perfectly however I have a specific bathroom light fitting to use which has only one electrical block connector with two terminals ie no earth. My next question then is this needs wiring differently to the standard ceiling rose and I old appreciate if you could please explain how I wire the switch cable and the mains ( loop?) cable.
Thanks
Jason

 

[securespark]

If your fitting only has two blocks, you will need more to connect the loop and the cpc's to.

Alternatively, you can connect the loop to a JB in the loft space and just run a single cable to the fitting. If the loft space is easy to access, a standard JB is OK. If not, use a MF JB.

 

[AndyPRK]

If you know how the normal rosé works, the outer 2 terminals will connect to the 2 terminals on the new bathroom light.

The wires in the middle rose block need connecting together in a seperate block.

And earths together.

 

[allgermanparts]

If you know how the normal rosé works, the outer 2 terminals will connect to the 2 terminals on the new bathroom light.

The wires in the middle rose block need connecting together in a seperate block.

And earths together.

Hello Andy,
As you were so helpful previously I hope you can help on another small project please. We have a new build house and want to fit an LED PIR outside light. In a nutshell is it a case of mounting the light to the wall > run a cable to a fused switch (perhaps in the garage where the fuse box is ) and from the fused switch to the fuse box. Also which size cable should I use please?
All the best
Jason

 

[AndyPRK]

If the cable is run inside without being exposed to sunlight flat twin and earth cable can be used. 1.0mm or 1.5mm.

Otherwise 1.5mm round cable could be used if outside.

You could run it to the fuse box if its close by or to a circuit in the garage.

Yes a fused dual pole switch should be fitted.

 

[EFLImpudence]

Why would anyone require 1.5mm² for one led light?

When was this policy of wasting copper introduced?

 

[securespark]

If you know how the normal rosé works

I know how it works.

You drink it, you get p*ssed.