How can I wire my 3 gang switch?

Thanks very much for your reply.
Yes I'm in the UK and understand there should be no 120v lurking around. So am very happy to take your advice and get an electrician in. I removed a switch that was functioning in the correct way but lost my note of where the original wires went. I was reluctant to 'experiment' and thought it a simple solution for a qualified person. There was a link (red) wire in the switch and that is the one that concerned me. I do have the two one-way lights working but the two way is still not functioning. Thanks again for your concern


Mike

Mike Morton
March 2008

You should get a properly qualified electrician and not mess with this yourself.
Having said that you will probably ignore that first (best) piece of advice anyway and therefore it might help to prevent an accident by giving you some info and bear in mind that this kind of thing does not lend itself to description solely in words.
Don't know what country you are in. But if you are in UK or Ireland your mains voltage (assuming single phase in a domestic house) is 220-240V. You should not have 120 V on one of those cables unless it is coming from a transformer somewhere. Assume you are replacing the existing with the same type of switch.
L1 and L2 occur in a 2 -way switch. You say the landing light is 2 way. There will be 2 "strappers" - 2 live wires (red in your case) running from this switch to the other 2 -way switch controlling the landing light. Word of warning: (1) both of these wires will not be live at the same time - it depends on the positions of each 2 way switch (2) Whoever wired them, may not have used the same colour cable for each and may even have used black cable (neutral)! The strappers are connected to L1 and L2 (doesn't matter which way around). COM is short for Common. The live wire bringing current to the first 2 -way switch is connected to COM - this one is always live. The other 2 way switch at the other end (say on the landing or down the hallway) also has a common terminal. The live wire leaving this switch and going to the light fitting controlled by these switches is connected to COMMON. It will only be live when both 2 way switches are thrown to the same "strapper" wire.
In a 3 gang switch you will probably find that there is only one live wire coming into the box. A short piece of live wire (red or brown in modern wiring) - or "link" will connect the COMMON terminal of the first switch to the COMMON terminal of the second switch and a second link connects the second COM to the COM of the third switch. There would be 6 live wires going out of the box, though. But this assumes that you are using all of the 3 gang 2 way switches as 2 way - one or two might be only one way. You can see that there are several possibilities!
Did you get all of that?
Best advice is get a qualified electrician!

J
March 2008