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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> 2 gang light switch https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1104513609 Message started by Chaddy on Dec 31^st, 2004, 5:20pm

Title: 2 gang light switch
Post by Chaddy on Dec 31^st, 2004, 5:20pm

Hi guys

I want to fit an outside light. i currently have a 2 way switch fitted in the kitchen. I was going to drill through the wall and fit a 2 gang switch. Can i pick up a live from the current set up and link accross to the 1 way side of the switch?
If so which one??
Cheers and Happy New Year to everyone. ;D ;D ;D ;D

Title: Re: 2 gang light switch
Post by Lectrician on Dec 31^st, 2004, 5:22pm

You will also need a neutral, and these are not always present in switches.

Take the plate of the wall, and tell us what cables are already behind the plate.

Title: Re: 2 gang light switch
Post by Chaddy on Dec 31^st, 2004, 5:24pm

That was a quick reply!!!

There are red(fitted in the common), 2 x yellow and 2 x blue(which is a switched live i assume as it has a red marker on it. plus an earth.

Title: Re: 2 gang light switch
Post by Lectrician on Dec 31^st, 2004, 5:48pm

No extra terminal blocks in the back of the box with a blue or black :(

Sounds like there is no neutral.

How many reds are there in the common? No other red lurking or chopped off?

Sounds as if they may have used a 3 core to drop from the pendent, which could be in your favour, as the spare core could be used as a neutral.

Any chance of a photo??

Title: Re: 2 gang light switch
Post by Chaddy on Dec 31^st, 2004, 5:51pm

Only one red in the common.

No other wires!!

Title: Re: 2 gang light switch
Post by Lectrician on Dec 31^st, 2004, 5:55pm

Yellow and blue suggests that 3 core and earth cables have been used.

These cables have 1xred 1xyellow 1xblue core, plus an earth.

Are you sure there isn't another red lurking??

Title: Re: 2 gang light switch
Post by Chaddy on Dec 31^st, 2004, 5:58pm

I'll have to check and get back to you.

It's possible that i'm having a silly moment.

Cheers

Ken

Title: Re: 2 gang light switch
Post by L.Spark on Dec 31^st, 2004, 9:23pm

Insult's to blonde people will not be tolerated here, sorry ;D

Title: Re: 2 gang light switch
Post by Chaddy on Dec 31^st, 2004, 11:22pm

What about bald people???

Suddenly got very pc around here!! ;D

Title: Re: 2 gang light switch
Post by L.Spark on Jan 1^st, 2005, 1:36am

wrote on Dec 31^st, 2004, 11:22pm:

Suddenly got very pc around here!! ;D

lol, not really 8)

Title: Re: 2 gang light switch
Post by Chaddy on Jan 1^st, 2005, 3:16pm

I'm glad about that!!!!

Theres too many do gooders in the world already!!! :P :P

Anyway the wires in the back of the switch are as follows....

Com- red
L1- yellow & red
L2-Blue & Blue with red marker

Title: Re: 2 gang light switch
Post by L.Spark on Jan 1^st, 2005, 3:35pm

Sorry I haven’t really followed this, You have a 2 gang switch of you have a 2-way switch?

Or it could be 2-gang & 2-way

2 gang's means 2 switches, 2-way means the light's can be controlled be either 2-way switch connected in parallel with each other.

Title: Re: 2 gang light switch
Post by Chaddy on Jan 1^st, 2005, 4:27pm

I have a 2 gang switch. one switch is wired 2 way. The other i wanted to wire up 1 way to power the outside light! ??? :o

Title: Re: 2 gang light switch
Post by Lectrician on Jan 1^st, 2005, 5:20pm

What colours go into the individual cable sheaths?? The colours still sound a little odd.

Title: Re: 2 gang light switch
Post by L.Spark on Jan 1^st, 2005, 5:48pm

Ok, so it's a 2 gang 2-way, with one 2-way and one 1-way.

It's probably fine lecc, but talking about it and seeing it are miles apart.

Quote:

Back to normality...

Whats that lecc? ;)

Title: Re: 2 gang light switch
Post by Lectrician on Jan 1^st, 2005, 5:51pm

Its currently a 1gang 2way.

He wants to put a 2gang 2way in, the extra ang for an outside light.

He want to run the cable from switch directly to light.

We are trying to see if there is a neutral at the switch, or if we could put one there, as it looks like 3 core has been used for the switch drop as well as the strapper.

Title: Re: 2 gang light switch
Post by L.Spark on Jan 1^st, 2005, 5:53pm

Well I would think it's unlikely theres a neutral there, however this is where it bugs me becasuse if he had a voltage indicator like we all do it would be found out in a few seconds if there's a neutral, but normal house goers just dont have these things ::)

Title: Re: 2 gang light switch
Post by Chaddy on Jan 1^st, 2005, 5:56pm

first time in a long time i've been called normal!!!

Title: Re: 2 gang light switch
Post by L.Spark on Jan 1^st, 2005, 5:56pm

lol, sorry my mistake, I was generalising :D :D :D :D :D

Title: Re: 2 gang light switch
Post by Chaddy on Jan 1^st, 2005, 5:59pm

Thats ok.

My Mum thinks i'm special!!! ; :-[

More like special needs ;D ;D ;D

Title: Re: 2 gang light switch
Post by L.Spark on Jan 1^st, 2005, 11:34pm

lol, we do it all here ;D

Title: Re: 2 gang light switch
Post by Chaddy on Jan 1^st, 2005, 11:36pm

Thanks for that L Spark.

Bloody good job!! ;D ;D

Happy New Year to you mate

Title: Re: 2 gang light switch
Post by L.Spark on Jan 2^nd, 2005, 12:45am

lol, you too

hope you get those switches sorted or some heads will roll :D

Title: Re: 2 gang light switch
Post by Chaddy on Jan 3^rd, 2005, 7:18pm

Hi all.
Checked today no neytarl in the box!! Typical.

I've got to have the carpet up in the hall next week. While it's up could i run a single cable from the CU on its own MCB from the RCD side of the CU??

That way i would ahve a neutral!!

Is this feasible?? :o ???

Title: Re: 2 gang light switch
Post by L.Spark on Jan 3^rd, 2005, 7:25pm

Quote:

Checked today no neytarl in the box!! Typical.

Had a feeling

Quote:

I've got to have the carpet up in the hall next week. While it's up could i run a single cable from the CU on its own MCB from the RCD side of the CU??

Not a single cable no, would be better to make a new box in the wall and run some new twin+earth to it from a new breaker, or alternatively run another twin cable down from an adjacent light fitting with a permanent live.

You must keep the same neutral that is associated with the live otherwise it's not safe and contradicts the regs.

In other words you can't take a neutral from another circuit on it's own, you must take a live and neutral from one existing circuit, or make another.

Title: Re: 2 gang light switch
Post by Lectrician on Jan 3^rd, 2005, 7:31pm

What cores did you finally settle on behind the switch then??

The colours didn't seem to marry-up with convention.

I would take another 2core from the original light to the switch, and from the switch to the outside light. Two blacks together in a terminal block, one red in com and one in L1 on the new switch.

Title: Re: 2 gang light switch
Post by Chaddy on Jan 3^rd, 2005, 8:09pm

Sorry LS when i said single cable i meant a 'radial' circuit with t+e. I assume a 6amp mcb is correct?

Lec looks like 2 3 core and earth have been run!! The earth in one being cut off.

Would've made that into the neutral that i required but the ceiling has been overboarded and the ceiling rose is below that!!!

Another job for the future!!

Title: Re: 2 gang light switch
Post by L.Spark on Jan 3^rd, 2005, 9:00pm

You shouldn't ever use the bare copper earth as anything other than earth, this is bare so that if there's any damage to the cable e.g. a nail get's put trough it then it shorts to earth, which is preferable than a short between live/phase and neutral.

Title: Re: 2 gang light switch
Post by ban-all-sheds on Jan 4^th, 2005, 11:27pm

wrote on Jan 1^st, 2005, 5:53pm:

More fool them.

IMHO, not buying a multimeter when you want to mess with your electrics is like not buying a hammer when you want to bang nails in.

Title: Re: 2 gang light switch
Post by L.Spark on Jan 4^th, 2005, 11:49pm

wrote on Jan 4^th, 2005, 11:27pm:

More fool them.

IMHO, not buying a multimeter when you want to mess with your electrics is like not buying a hammer when you want to bang nails in.

Yes perhaps

Multi-meters are good but they have there limits, and seeing as you could make mistakes if you don't know how to use one, set it wrong and then find the cable's still live.

Title: Re: 2 gang light switch
Post by plugwash on Jan 5^th, 2005, 12:05am

the biggest danger with using a multimeter to prove dead is taking a bad reference

ie say you decide to measure voltage phase-neutral to prove dead

you check with the meter and get a voltage

turn a switch off check again and get no voltage

touch one of the cores and get a shock because there was a switch in the neutral.

Title: Re: 2 gang light switch
Post by Lectrician on Jan 5^th, 2005, 7:29am

I always test as normal, then put a probe on the wall - you always get near full volts.