Changing double gang switch change

[Carlos1976]

hi all new member needing help bought a double gang switch today from bq went to swap over all connections are marked different new switch has L then L1 then 2 This on both banks old two way switch has 5 going into it two red on blue yellow and a black could any help how it connects to new switch I'm guessing the L new switch are the commons

 

[PrenticeBoyofDerry]

L does mean common
Then you will have L1 and L2, not all switches are marked or designed the same, so pictures of both switches would be helpful.

This may help
https://www.diynot.com/wiki/Electrics:Two-way-lighting

 

[Carlos1976]

hant dissconected old switch as didn't want to messing wiring up

 

[Carlos1976]

 

[Carlos1976]

That's old swith still connected

 

[Carlos1976]

New switch has L then L1 and l2 on both banks it's connected to a single switch at top of stairs which has and coloured earth in to com then two reds in a terminal then black and blue wires connected to another terminal guessing these are neutrals

 

[PrenticeBoyofDerry]

coloured earth are you sure?
One of the gangs looks like a single way?

 

[stillp]

hant dissconected old switch as didn't want to messing wiring up

Well done!

 

[Carlos1976]

Same colour as that yellowed green on that's on switch one below blue

 

[Carlos1976]

That is wired to the single switch on its own then two reds together then blue and black wires together

 

[EFLImpudence]

It IS yellow.

One cable to one switch is Red, Yellow, Blue

and

one cable to other switch is Red and Black.


These are the two switches - just swap the wires.
One switch may be upside down like this is or they may both be the same way up.

 

[PrenticeBoyofDerry]

Same colour as that yellowed green on that's on switch one below blue

That is not an earth, it is a switch line. Ideally all the conductors connected to the switch should be sleeved red, none are neutrals all live.

The red and black cores to right of photo are part of a single gang, would assume the red is com/L and the black is L1.

The other gang is two way, again assume yellow is com/L and Red is L1 and blue is L2.

The conductor connected to backbox, sleeved green/yellow is the earth (aka CPC). This should stay connected unless you have purchased a metallic switch, then the CPC needs connecting directly to the earth terminal on the switch plate, then ideally a supplementary earth between the switch plate and backbox would be installed.
The most important thing to establish is if you are replacing with a metallic switch plate? That there is a fault path to earth, so continuity must be proved via testing.

 

[winston1]

New switch has L then L1 and l2 on both banks it's connected to a single switch at top of stairs which has and coloured earth in to com then two reds in a terminal then black and blue wires connected to another terminal guessing these are neutrals

Guessing is not a good idea with electrics. What is more you would be wrong. There are no neutrals to those switches, they are switched lives.

 

[ban-all-sheds]

Same colour as that yellowed green on that's on switch one below blue

Yellow and green&yellow (or yellow&green) are not the same.

The clue is in the names describing the colour(s) not being the same.

On a more general note, what are your thoughts on the wisdom of someone who thinks that it's OK for a switch to be wired so that it directly connects live to earth doing electrical work?

Or the sort of person who thinks that it's OK for a switch to be wired so that it directly connects live to neutral?