changing 2 gang, 2 way light switch - HELP!!

[barryman]

I need to replace a faulty metal plate two gang, two way light dimmer switch (photos: switch 1 and switch 3). As we never use the dimmers I have just bought a non-dimmer ordinary metal plate two gang, two way switch (photo: switch 2). The trouble is I have about 10 wires going into the old one and a different simpler layout with three connections on the new one.

So, can anyone just tell me where & what I should be doing with the wires and how to wire them into the new one? Do I lose a few wires somewhere or what?? Will the earth be OK? Help!

By the way, please answer in simple terms so even a semi-idiot like me can understand!! If answering this it may be easier to refer to connectors on Switch 1 as 1,2,3,4,5 & 6. I am in UK so it's UK wiring.

Many thanks in advance.

switch 1

• barryman
• 18 Jun 2014
• 1

switch 2

• barryman
• 18 Jun 2014
• 1

Untitled

• barryman
• 18 Jun 2014
• 1

 

[bernardgreen]

Can you mark up the picture showing how the brown and blue wires are paired in the gray sheaths.

Where are the earth wires ? Unless there effective earth wires ( meaning there is continuity to the earth terminal at the fuse box ) you cannot have switches on a metal face plate.

 

[barryman]

Bernard - I cannot work out how to private message you on this site so here's answer:

I have looked behind switch but all wires, browns and blues, are just coming out from behind the box. There is no grey sheathing visible to me. Also, I notice on the back of switch that there is no wiring connected to the earth lug. Pardon my ignorance but does the fact that I have got a "quick-trip" fuse box mean they didn't need the earth??

So, there's not much more I can add to the info. Just as you can see in 1st photo !!

 

[bernardgreen]

You do need the earth if the switch plate is metal. It doesn't matter what type of fuse box you have. The existing switch appears to have a metal front plate without an earth. If it is metal then the "electrician" who wired that switch did not comply with the regulation about earthing and this suggests he may have failed to comply in other ways.

Are there are markings on the rear of the existing switch ?

 

[rjm2k]

Post a photo of the inside of the back box so we can see what's going on in there, also if you can post a photo of the back of the existing switch where the terminal markings are

 

[AndyPRK]

So you have another dimmer switch in that room, controlling the lights ?

I have just posted a third photo - it's not great but it's the furthest I can pull the switch out of the wall to get the photo. It shows where things are going in but i cannot get a shot of any markings. There is an earthing lug there as well.

Also, for the record, this switch which is the two gang, two way. The other switch at the other end of my lounge is a straightforward on/off switch. It is actually a three-way switch as it also controls another light. My point being that it is not a dimmer.

Untitled

• barryman
• 18 Jun 2014
• 1

 

[Taylortwocities]

On what you call "switch 1" what are the terminals marked at as they are viewed from above, as in the photo.?

Or post a picture of the back so we can see/.

 

[JohnW2]

Am I the only person who is struggling to understand how/why, if the old switch really is '2-way', two of the terminals of each switch have two conductors (a pair of blues and a pair of browns for each switch)?

Kind Regards, John

 

[EFLImpudence]

if the old switch really is '2-way', two of the terminals of each switch have two conductors

IF... - we can only assume three twin+earths have been used as strappers instead of two three-core+earths.

If that is the case, it is good to see that someone has not used the CPCs as live conductors.
It is just a pity that they don't seem to have used them as earths either.

 

[JohnW2]

if the old switch really is '2-way', two of the terminals of each switch have two conductors

IF... - we can only assume three twin+earths have been used as strappers instead of two three-core+earths.

Indeed - but given that, for each switch, two of the three terminals have two conductors going to them, that means that at least one (possibly both) of the 'non-COM' terminals of each switch has two conductors going to it - and I still struggle to understand what that could all be about! Another possibility (hence my 'if' regarding the '2-way'), I suppose, is that they are 1-way dimmers and one of the terminals is a neutral.

If that is the case, it is good to see that someone has not used the CPCs as live conductors. It is just a pity that they don't seem to have used them as earths either.

Indeed, particularly since I presume that those CPCs must exist - I presume that brown/blue T+E without CPC was never made?

Kind Regards, John

 

[Taylortwocities]

There seem to be 5 sets of twin and earth in play here.

From the top on that picture I guess its COM L1 L2 then COM L1 L2

So, someone did not have any 3-core and earth and has run a twin and earth as the strappers between the COM terminals, two twin and earths as the strappers for the L1 and L2 connections. This leaves two twin and earths which are the live and switched live for the two lights.

I ma hoping that the OP can confirm the terminal markings, then it should be a simple job to transpose the wires one at a time to the new switch.

 

[JohnW2]

There seem to be 5 sets of twin and earth in play here. ... From the top on that picture I guess its COM L1 L2 then COM L1 L2 ....So, someone did not have any 3-core and earth and has run a twin and earth as the strappers between the COM terminals, two twin and earths as the strappers for the L1 and L2 connections.

That all seems quite probable but, as I've just asked, if your (and my) assumptions are correct, how can/could you explain two conductors going into each of the L1 and L2 terminals?

Kind Regards, John

 

[Taylortwocities]

Check out the standard two way switch wiring. Two conductors in L1 and L2 and one conductor in COM.

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

Simples!

 

[JohnW2]

Check out the standard two way switch wiring. Two conductors in L1 and L2 and one conductor in COM. ... Simples!

Ah, yes - 'standard two-way switch wiring'. You won't find any of that in my house (only one conductor in any L1 or L2 terminal here!), so I suppose my subconscious thinking about two-way switch wiring rather gives away my age Thanks for the 'jog'!

Kind Regards, John

 

[Taylortwocities]

www.youtube.com/watch?v=3f94P4puUbc