using a 3 gang 1 way switch for 2 lights

[BILLDIYNOT]

Hello. Newbie looking for how to connect a switch correctly. I have a Legrand K40131 10AX 250v light switch with 3 rocker switches on it. In the pattress are 2 sets of red, black and earth sleeved wires. These wires switch on 2 sets of wall lights in the living room. There were connecting red wires in the old switch between all 3 com connection points. the 3rd switch on the old switch unit was used to turn fluorescent lights on/off. I have disconnected these and removed all of the fluorescent control units and wiring. The back of the new switch has 3 connections identified as L and 3 other connections with no id at all. (See pic) When I removed the old switch and had all of the wires bared, I checked which was live. ( Yes, I am still here so must have done the safety stuff right ). Only one of the red wires was live. I got no other indication of power to other wires via the fluke tester and electricians' screwdriver I used. I have connected the new switch by putting each of the 2 red wires to an L and their corresponding black wires to the unmarked connections indicated on the back of the switch. The wall light worked with the switch with the live wire. The other did not. It sounds like I just need to have a connecting wire between the 2 L connections to supply power to the 2nd switch. But then I have been logical with this all along, so I may be wrong and I am now at the point where I am not sure.... Your expert direction would be appreciated.

 

[PrenticeBoyofDerry]

You need to link the permanent live between gang 1 and 2 at L.
Is there anything else that does not work?
As you would not need the red core currently in the second (other switch/not wall lights) gang at L, unless this was supplying a live elsewhere.

 

[BILLDIYNOT]

Thanks for your quick reply, PrenticeBoyofDerry. I am not aware of anything else not working. I assumed that the 2 sets of wires were one for each of the wall lights. Can you confirm that I still need to connect the 2 black wires to separate switch connections but only connect the live red to one with a connecting red wire between it and the other L connection. Should I just put a block on the other, now seemingly redundant, red wire or actually connect it to the other switch L connection ? I have, hopefully, attached 2 pictures of the original wiring in the original switch. Hope it helps.

 

[BILLDIYNOT]

I have connected one red wire to an L. Its partner black wire to the accompanying unidentified connection. I have done the same with the other set of red and black wires. This time I have also made a bridge connection between the 2 red L connections. One switch works it corresponding wall light on/off. The other switch does not work but now the other wall light is on permanently. There is another set of connections available on the back of the new switch. What am I doing wrong ?

 

[EFLImpudence]

This is all you need, if the above is correct:

If that doesn't work use the red of the right hand cable instead.

Why did you not buy a two gang switch?

 

[EFLImpudence]

I would point out what novices don't seem to realise.

That 2-gang or 3-gang (or however many-gang) are just that number of SEPARATE switches stuck together.

They are not some mysterious contraption with 6, 9, 12, or more terminals.
They are just that number of switches with 3 terminals each in triangles.

 

[ban-all-sheds]

I would point out what novices don't seem to realise.

Which is shameful.

 

[BILLDIYNOT]

Thanks EFLImpudence. The original switch, which you have marked, was a 3 switch unit. Apart from 2 of these switches being for separate wall lights, there was a switch to turn on fluorescent lights under the living room pelmet. After having bought the new 3 switch light switch unit, I decided that I did not want the fluorescent lights but I would like to have the flexibility of the 3rd switch for something LED in the future. I accept that, in the meantime, the 3rd switch will not do anything. However, the suggestion you offer is based on the old switch. The new switch is different. I have posted a pic of the new switch. I would appreciate your advice regarding how I can get both wall lights working via separate switches on this 3 switch unit. Thanks.

 

[ban-all-sheds]

It shows you on the back which terminals go together....

 

[BILLDIYNOT]

In case the pic is not good, the new switch does not have L1,L2 or common shown on the back. 3 connections are identified as L and the other 3 are not identified. Given that this is a 3 switch unit, there are 2 terminals for each switch, not 3. This was purchased as a 3 gang 1 way switch, which is all I need. I understand, even as a novice, that there should be a logic regarding how these things are connected. My logic would be L = Live (in the case of this wiring, red), so I would, logically, put the 2 red wires into 2 L connections and the 2 black wires into the unidentified partner connections to these 2 reds. Only 1 switch worked. Using a link to connect the 2 reds gave the same result except with the other wall lights on permanently. The nature of what I am handling makes me, appropriately, cautious. I appreciate the expertise made available on these forums to help willing DIYers like me to do the right thing and learn at the same time. I hope my additional information can enable you to suggest the connections I need to make to complete this installation. Thanks again.

 

[BILLDIYNOT]

Ban-all-sheds, what the back of the switch unit shows me is terminals for live and an indication of switches. I believe I have one live, red, wire. I know I have 2 sets of red and black wires. I know I can get one set of wall lights to work via one of the switches on the new 3 gang switch unit. I know, currently, that I cannot get the other set of wall lights to work via a switch on the new 3 gang switch unit. Hence my request for guidance

 

[EFLImpudence]

Very odd configuration.

After reading again, it would seem you need to use the red of the 'not live' cable.

 

[AndyPRK]

It's certainly a new layout to me. And as you say 1 way.

The raised middle portion requires the live wire connecting to the 2 switches you intend to use. (you will need a short piece of wire to loop between the two)

The bottom row of terminals are the outputs for connecting to the lights (L2 previously) (usually black wires, 1 red in your case)

 

[BILLDIYNOT]

Success ! Thank you. Should I put a block on the spare black wire or tape it up or something ? Can you also explain the yellow circles you highlighted and which of these connections I should consider as L1,L2 and Common ? Everyone seems to talk in these terms and I can't make the link of my understanding between those standard terms and the switch I bought.

 

[BILLDIYNOT]

AndyPRK, Thanks for the explanation of the terminals. Very helpful.