2 Gang 2 Way Light Switch - Replacing

[pbar]

I would be grateful if someone could help me with replacing a 2 gang 2 way light switch please.

The one I'm taking off has different terminals than the new one. I could make it easy on myself I guess and try to buy one with the same terminals, but most seem to be like the new switch which I have.

I haven't taken the old one off yet, as I didn't think it wise until I'm sure of what I'm doing.

Both switches control two different lights, and each of those lights has a separate single switch elsewhere which control them also.

All works perfectly at the moment.

The old brass switch is as follows -

At the top it has COM (red wire) L1 (red wire) L2 (red wire)
On the bottom it has L1 (red wire) L2 (black wire) COM (red wire)

It also has a small red wire linking the top and bottom COM terminals.

The new white plastic switch is like this -

At the top it has COM COM
At the bottom it has 1 way 2 way 1 way 2 way

Is it possible please to wire this new switch to work as the old one did?

Thank you very much.

 

[ericmark]

Simply 1 way = L1 and 2 way = L2.
However the link Com 1 to Com 2 makes on think wired as taught at school not normal way electricians use. So you need to note carefully how wired as the diagrams on here will likely not match your system.

 

[Taylortwocities]

Look at the old and the new switches. it sounds like the old one is laid out like this

2 gang switch layout

• Taylortwocities
• 31 Aug 2009
• 16

.
So you have two switches side by side, but one is upside down.

The new one is probably two switches side by side but the two coms are at the top.

Take a photo of the old one before you disconnect ANYTHING.
And take a photo of the new one.

You can then post them on here if you get stuck...

 

[pbar]

Thank you very much for your quick replies guys, but I think I might need it explaining. For example, the old switch has 3 terminals at the top (and bottom) as I mentioned, but the new one has only two. I understand that L1 and L2 are one and two way.

 

[TicklyT]

The designation of the terminals is important. The layout of the terminals on the back of the switch varies between manufacturers.

Note the diagonal line on the diagram TTC supplied. That shows the division between the terminals for the two switches. Mark your wiring on that diagram, cut it in half along that line, flip one half upside down and you will have a diagram of your new switch.

 

[pbar]

Thank you, and looking at all of the replies, I think I'm getting it. Can you tell me, do I still need to link the two COM terminals with a small wire on the new switch?

 

[ban-all-sheds]

Of course.

You don't mention any earths - was that just for clarity, or do you not actually have any?

 

[pbar]

Yes, the earths are there, as they should be.

 

[pbar]

Well, I changed the switch and all is fine, more straightforward than I thought, don't know what I was worrying about now. Thank you all, for taking the time to respond and help.

I'm interested to know - what is considered good practice as regards to two way switches, i.e. should both switches be able to be in the off position with the light off, or does it make absolutely no difference.

I ask because with doing this, and checking it all works, I've noticed that on one of my two way switches, both of the switches can be in the off position with the light off.

Yet, with the other that I have, the light is only off when both switches are opposite, i.e. one is in the off position, one is on.

Does it make any difference to you guys, would you be happy leaving a job that way?

Am I right in assuming that changing over the L1 and L2 connections on one of the switches makes it work the opposite way, as if it was upside down.

 

[EngStudent]

Does it make any difference to you guys, would you be happy leaving a job that way?

Am I right in assuming that changing over the L1 and L2 connections on one of the switches makes it work the opposite way, as if it was upside down.

It doesn't matter which is which, sounds like you've possibly got the connections swapped round. Changing L1 to L2 and vice-versa would make it work the 'opposite' way, yes.

 

[pjcomp]

At some point two way switches are going to b e in the "wrong" position. Start with the light off and both switches in the off position. Turn the light on - one of the switches is now "wrong". Use the "wrong" one to turn the light off, and now both are in the "wrong" position. ....


PJ

 

[pbar]

At some point two way switches are going to b e in the "wrong" position. Start with the light off and both switches in the off position. Turn the light on - one of the switches is now "wrong". Use the "wrong" one to turn the light off, and now both are in the "wrong" position. ....


PJ

If you cannot start off with both switches off though (i.e. with the light off that way), then the above scenario cannot be recreated. That's what set off my question as to what's considered good practice as one set of two way switches does work that way, and one doesn't. Although they all work ok.

 

[pbar]

It doesn't matter which is which, sounds like you've possibly got the connections swapped round. Changing L1 to L2 and vice-versa would make it work the 'opposite' way, yes.

Thought so, thanks.