2 gang dimmer

[paulisere]

Hi i have decided to change my 2 way light switch in my daughters bedroom to a 2 way dimmer ,the switch at the moment is for her bedroom and the loft. I thought it would be a simple straight swap but when i removed the switch there were four red wires and an earth. i tried to change the wires over like for like but when i turned the power back on only the loft light worked i also connected the short red wire which i forgot to mention com to com . i then tried changing the wires round.this resulted in one switch operating both the loft light and the one in the bedroom.to make matters worse i was going to put the old switch back and now because they are all the same colour i cant remember where they went originally. at this point i have taped all the wire up.and i am waiting to see if anyone can help,stupid i know i should have made a note of how the old setup was
p.s don't shout at me.Thanks

 

[scott6471]

Hi Paulisere,

It sounds like you have your wiring done in a conduit system. This isn't like Twin and Earth where you would expect to find a red and black core for each light circuit (in this set up the black should be oversleeved as it is actually a return live conductor).

When you say four reds are you including the short one that was fitted across com to com?

Scott

 

[paulisere]

no scott 4 plus the short one .it was L1 TO L1 L2 TO L2 AND I THINK THE SHORT ONE bridged from L1 TO L1 .

 

[scott6471]

Sounds like one of the switches is two way!. Do either the loft or the bedroom have another switch that would operate the respective light?

In a nutshell, the short link cable is likely to have gone between Com and Com as it is usual to do this when bridging switches on the live side i.e. Live feed into Com on switch 1 and from switch 1 to com on switch 2.

Strappers are the term we use when linking 2 remote switches to make them operate two way, just like your hall and landing light switches

Scott
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[Steve]

Sounds like one of the switches is two way!.

No it doesn't. Its a bedroom and a loft!

He has live feed, live out, and 2 switched lives!

Firstly, determine which red is permenant live. Do this by putting a multimeter on volts AC between the reds in turn, and the metal switch box.

Put this in COM. Put the link wire between the 2 COMs. Now, connect one of the remaining reds to L1 of the first switch. Try it. If this doesn't have the desired effect, try another.

Then you will have two remaining reds. One feeds the rest of the circuit. This goes to COM. One feeds the other light which you didnt connect to switch one. This should be easy enough.


By the way its bad practise to have a loft switch where you cant see whether the light is on. A grid keyswitch would have been a better solution if you must have the switch here!

 

[scott6471]

By the way its bad practise to have a loft switch where you cant see whether the light is on. A grid keyswitch would have been a better solution if you must have the switch here!

Yep Steve in hindsight you're quite right, it likely is live in live out as you suggested, but what if the bedroom is the last on the circuit and there IS a light switch next to the bed for instance?!. It's possible it could be either.

Paulisere. if there isn't another switch in the bedroom follow the steps Steve has advised.

I'd have to say putting a key switch in would be far worse practice than having the loft switch outside the loft. What if you lost the key? And god forbid they move house and the next owner isn't left the key, there'd be another poor soul posting on here asking "what's this funny switch i have in my bedroom?"


Scott

 

[Steve]

New keys (MK fish keys or MEM) cost a matter of a few pence and are generic. It only serves as a precaution so that it isn't accidentally turned on. You could tape the key to the switch if you wanted!

One solution would be:
http://www.tlc-direct.co.uk/Products/MKK4501LV.html
http://www.tlc-direct.co.uk/Products/MKK4881.html
http://www.tlc-direct.co.uk/Products/MKK4889R.html
All in
http://www.tlc-direct.co.uk/Products/MKK3633.html
http://www.tlc-direct.co.uk/Products/MKK3703.html
http://www.tlc-direct.co.uk/Products/AP665.html

The dimmer for the bedroom
The switch and neon for the loft light.

 

[paulisere]

Thanks guys for replying ,i'm goin to have a go at what you suggested steve this afternoon will let you know how i went on ,thanks again.

 

[paulisere]

Thanks for your help steve followed your instructions and it now works a treat mate,your a star.also thanks scott.