Hall way lights re-wire questions. Thanks

[dude_diy]

Hello guys im having problems re-wiring my hallway light switch after replacing the switch covers and need some advice. Any help is really appreciated.

I basically have 2 seperate cieling lights.

-1 light on the upstairs landing, which is a single switch, but this also works from a double switch down at the bottom of the stairs as well
-1 light at the bottom of the stairs which is a lobby light which works from the double switch at the bottom of the stairs as well.

On the back of the single switch at the top of the stairs I have 3 terminals
L1 L2 L3 and 4 wires, red, yellow, blue and earth. Im fine with where the earth goes.

On the back of the double switch at the bottom of the stairs I have 6 terminals. 3 at the top L1 L2 L3 and 3 at the bottom L1 L2 L3. From the wall theres 7 wires. 2 of theses are earth, so 5 wires. 1 red 1 yellow and 1 blue ( same as upstairs ) also a slightly heavier core cable in black and red.

I just need to know how to re-wire. I did make notes on taking off the old switch facias, but rewiring the same doesnt work. Whats happening at the minute is the lobby light is turned on and off from the double switch.

- i dont own a multimetre
- also is the L3 terminal another name for common?


thanks in advance for any help

 

[Lectrician]

I have rarely used switches with L1 L2 L3, and when I have, I have metered them out each time to figure out which is the common. It is likely to be L3, or L1.

The three core + earth cables are used for the two way switching of the landing light. Could you look inside the landing light pendent to what cables are there? I suspect that the three cores go back to there which is not that unusual, but we need to confirm this first.

 

[dude_diy]

Thanks for getting back to me. Ive looked in the landing light pendant and theres just the Black, red and earth. So it isnt the 3 core as you susspected. The cables heavier as well, like whast behind the downstairs switch. The cable leading to the lobby light is also just neutral (black) and live (red) and earth.??? any further advice. Ive also just been out and bought a multimeter.

 

[Lectrician]

Well, use the multimeter to figure out which the COM is on the switch.

Using low ohms (or BEEP), look for continuity between two terminals. Then operate the switch. Again, look for continuity betweem two terminals. The terminal which was used on both tests is the COM (common to the other two).

There must be a joint box in the loft somewhere that marshalls the two three cores, the landing light cable, and a feed or two. Finding this, and then figuring out what colours they have used for the three cores would help, but we can go trial and error if this joint box is not obviously placed....

On the 1 gang switch upstairs, lets go the older colour code.....RED to the COM, and yellow to L1 and blue to L2 (assuming these are L1 and L2 - beeping the switch out will let you know!)

On the downstairs switch, on one side of the switch for the upstairs light, copy that of the upstairs switch. On the other switch, but the red and black either way around in the terminals you find to be COM and L1.

Try that and see, if it doesn't work, we can try another colour code.

 

[ColJack]

the switch doesn't work like top and bottom.. it's set out in 2 triangles..

L1 one side coresponds with the L2 and L3 the other side, and vice versa..

you also seem to be missing a set of cables somewhere..

you need a second set of red/black wires to go onto the 3 core, since you said you can't see it at the light itself..

is there another light somewhere that's on the landing? as there are only a red and black wire at it, this sugests that it's a second light from a main light.. or indeed a junction box..

 

[dude_diy]

Hey lectrician, thanks for you help so far, youve been great mate.

Well, I was just about to start following your instructions this morning, multimeter in hand. I removed the double switch cover just to familiarise myself again. Then was just about to turn off the supply. I gave the switchs a quick test and the circuit seems to work.

I did initially rewire pretty much like for like when I repleced the switch cover, so cant understand why it didnt work and now with the cover slightly removed ( hanging by wires ) its does?. So all seems fine. I will follow your advice and run a few test (seems a shame not to play with my new toy)

Any ideas on what could of caused the lights not to work???. I though ti may of been an excess of wires behind the switch plate, but all the wires fit well??.......im very curious??? what do you think mate???

 

[TicklyT]

Check you haven't pinched the wire insulation under any of the terminal screws. That may allow an intermittent contact, working when the switch is moved.

It could lead to intermittent operation, arcing, local overheating, burning of the cable condictors and insulation and possibly even a fire

 

[Lectrician]

Yep, and it could also be the switch itself. I have seen cheap ones which work happily until you fix it to the wall, the cables putting pressure on the terminals seem to move the switch contacts out of the way.

 

[dude_diy]

Well the plot thickens!!!...checked all the wiring and found a live feed wire which had snapped inside its casing.Thought this must be the problem. Basically sorted that out and the lights worked fine for an hour. Now there not working again. Ive also made sure not of the wires are putting pressure on the terminals. The fittings ive bought as well are from CEF not cheap ones either....Any further ideas or checks I can do??? once agin thanks guys for all your input.....it seems to be based around the upstairs single switch which works then stops working, but im just guessing! Thanks