New style switch, but old cable?

[John Hanslip]

Hi there. This is my first post and must say this site is a god send. I wish I'd have known about it when I started doing this wreck of a house up.

Ok, this is probably a pretty easy question for most but I am rubbish with electrics. I want to replace an old 2 gang switch for a new nicer steel one. I am not changing the wiring, that can stay where it is. However, it would seem the rear design of switches has changed since the original white plastic type. I mean, what the hell is L1, L2, L? hehehe.

What I basically want to know is where do the wires go? You can see how they are at the moment in the old switch, what I want to know is where do they go in the new one? I've read not to use metal switches if there is no Earth, but as you can see there is. I can figure the earth bit out.

I am asuming red is Live and Black is neutral right. So as you can see there are 3 cables coming down in to the switch box. Cable 1 has 1 live and 1 earth coming from it. Cable 2 it would seem has just 1 live, and cable 3 has an earth, a live and a neutral. To me this makes no sense.

It is done like this I think, because...

So, I know there are a lot of pictures and waffle there for what is probably a dead easy question, but I wanted to try make my query as understandable as possible. Thing is, i've done things without asking advice before and... well, i'm lucky. hmmmm.

Any help would be great.

 

[Lectrician]

Your pics are great.

Simple one this.

One of the core og the twin red cable needs connecting to the two L terminals on the new switch. This must be the core that has the bridging link on it currently. At the moment it is connected to the com terminals (COM of the old switch is L of the new switch).

The other red from the twin red needs putting into an L1. From the pic of the back of your switch, lets say the bottom row, 3rd from left.

The red and black from the other cable need to go the the L1 and L2 of the other side of the switch, either way around (doesn't matter). These are the 2 bottom left terminals on your pic.

If the two-way switched switch operates the wrong way (when both the two way switches are in the same position, the light should be off), then interchange the red and black of the twin cable. Doesn't really matter, im just pedantic.

Make any sense??

 

[Adam_151]

I've labeled your pic of your old switch with the same labels as your new switch, its just a case of transposing the connections now

http://www.electro-zone.co.uk/upload/images/Adam/SWITCH.JPG

(the purple line separates the two halves of the switch, its clear on the ew one because its got two clearly defined black areas)

Take the earths to the earth terminal on the switch and take an earth wire from this to the backbox earth terminal

BTW, there are no neutrals there, there are lives, 2 way strappers, and switched lives, the blacks should be identified with red sleeving

 

[Lectrician]

I cant ignore the pics.........here ya go!

 

[johnny_t]

My guess would be that the top row of the old switch represents L of Switch 1, L1 of Switch 2 and L2 of Switch 2. The bottom row represents L1 of Switch 1, L2 of Switch 1 and L of Switch 2.

You would normally have the two L's linked together, but as you are using Switch 2 in a one-way configuration it doesn't really matter.

Good Luck !!

 

[johnny_t]

Must be a record. Three extra replies, two with edited pictures, in the time it took me to type that !!!!

 

[John Hanslip]

Brilliant guys, thank you so much. You should be charging for this service. I will give this a go tonight when I get home. I am going to read up about the red sleaving thing, just to figure out why you need to do it, as that's the only bit I don't understand now. (why put red tape over the black wire?)

But seriously, thankyou all for taking the time to reply. I will try to put back in as much as I take out of this site somehow.

 

[JACKC]

Dont forget to change the green sleeve for yellow/green as green alone is a non compliance to bs7671

 

[ban-all-sheds]

Nice to see that there's a grommet there, though - you don't always...

 

[Steve]

(why put red tape over the black wire?)

because it is live, not neutral[/quote]

 

[kai]

I am surprised that the cable colours are not Red, Yellow and Blue, with the yellow connected to the common terminal on the switch, that being the traditional two way lighting circuit colours.

 

[plugwash]

afaict 3+E used to be a lot less common and this is about the easiest method to do two way switching with only T&E.