terminal confusion


Postby duchwilky » Wed Oct 15, 2008 5:46 pm

Hi everyone im new and i appreciate your help.
I have a 3 gang switch connecting to 3 lights one of which is on a 2 way switch for the landing light.
whilst this light works the switch doesnt i can switch it on from down stairs and then switch it off from upstairs but i cant switch it back on from here. any ideas?
this is how the 3 gang switch is set up - positions are as if you are looking through the face plate
2 x twin and earth cable going into the switch.
cable A: wire with brown sleeve into left com/ red into right com/ black into midle com.
cable B:black into middle L1/red into right L2
left and right L1 are not used. 2 pieces of wire strappers? go from right com to middle L2 and from there to left L2
The switch on the landing has twin and earth going into and out of a 2 way switch- red to L1 black to L2 live from light going into com.

Any thought on where its all gone wrong would be appreciated
Thanks
duchwilky
Rank: Labourer
Progress to next rank:
50%
Posts: 3
Joined: Wed Oct 15, 2008 5:21 pm

Sponsor

Simply Build It

Postby Sara H » Wed Oct 15, 2008 10:44 pm

Duchwilky - two way switching normally requires the use of a 3 core and earth cable 6243Y cable. Unless you have a third core going from your light switch then sorry to say its a bodge job

HTH
Sara
Sara H
Rank: Apprentice
Progress to next rank:
15.8%
Posts: 8
Joined: Wed Oct 15, 2008 10:27 pm

Postby ericmark » Thu Oct 16, 2008 6:42 am

Look at http://www.ericpalmer.fsnet.co.uk/Lighting.html I have explained how three way switching works. You say two twin and earth cables which may mean there is some neutral borrowing I have tried to explain how this can be a problem. If there is a single lighting supply you can get around having only twin and earth. See what you think and come back.
Eric
ericmark

Postby duchwilky » Thu Oct 16, 2008 11:02 am

sara h - thanks for the bad news there definately isnt 3core and earth anywhere around this switch.
eric mark - great website and im sure my answer is there but i just cant get it.
This switch did work when I first moved in. and stopped after I changed the switch face plate some while ago I noted where everything went and thought I changed it to how it was - obviously not. Can I ask what wires would connect to the switch terminals to make this work. as you may have guessed im fairly hopeless at this but not dangerous - if the answer is to complicated Ill leave well alone I just think though that its just one wrong wire. Would this wiring setup not be how it was done 10-15 rears ago.
Thanks once again
duchwilky
Rank: Labourer
Progress to next rank:
50%
Posts: 3
Joined: Wed Oct 15, 2008 5:21 pm

Postby ericmark » Fri Oct 17, 2008 10:17 am

Please remember as Sara H says this is a "bodge job" I show it in the last two diagrams.
First thing to remember all switch wires should have been red or now brown although we do use the other colours by used sleeves this is only to save money and therefore there is no colour code.
At one of the switches you should have standard switch wires which go to the lamp and also a pair of wires that go to the other switch.
Assuming switch marked com and L1 plus L2 then from lamp the live wire goes to L1 or L2 and the switch return into the one left again L1 or L2 the strapper wire goes to the switch wire to lamp and to Com.
At the second switch put the strapper wire in same holes as the first switch.
The second switch has to be one of a pair and this is the cheat you find the live wire on the other switch and put a bridge wire between that and the vacant L1 or L2.
This can only be done where the two lights come from the same fuse or MCB and it causes a lot of problems when RCD's are fitted because if they are not from the same fuse or MCB it creates a borrowed neutral which is very dangerous it was done a lot years ago when houses would normally only have 4 fuses but as well as borrowed neutral problem it can also cause interference and with wireless LAN and the like courses no end of problems.
It is a bodge job and I would not recommend it.
Eric
ericmark

Postby wilkyduch » Fri Oct 17, 2008 11:25 am

Eric thanks for that and for bearing with me. theres a couple of things Im not sure about if you dont mind clarifying.

you say
At one of the switches you should have standard switch wires which go to the lamp and also a pair of wires that go to the other switch.
Are you talking about one of the switches making up the 3 gang? (comL1L2) which of the standard switch wires goes where
And when you say pair of wires that go to to the other switch is this the one on the landing or a switch next to the first within the 3 gang
You say
Assuming switch marked com and L1 plus L2 then from lamp the live wire goes to L1 or L2 and the switch return into the one left again L1 or L2 the strapper wire goes to the switch wire to lamp and to Com.
Sorry Eric Im lost - within the 3 gang there are 3 x (com L1 L2)

You say
At the second switch put the strapper wire in same holes as the first switch.
The second switch has to be one of a pair and this is the cheat you find the live wire on the other switch and put a bridge wire between that and the vacant L1 or L2.

It would help me if i could refer to the switches in the 3 gang as A Band C

Thanks for all your help - Tina
wilkyduch
Rank: Labourer
Progress to next rank:
25%
Posts: 2
Joined: Wed Oct 15, 2008 5:17 pm

Postby ericmark » Fri Oct 17, 2008 6:12 pm

The reason I was so vague is that it will depend on exactly how your house is wired. Normally with a three gang switch every light is independently wired but since you don’t have a three core cable the electrician has not followed this idea.
Looking at the bottom of the web page there are two drawing if you look at the top one at the top of the drawing I show four switches the top two are the two way switches and the bottom two just show how they connect with the other switches the bottom right hand you can see is linked to top right hand it is this link that causes all the problems. Although I can show how it is done I can’t guess how your house is wired and if you will need to get an electrician who will most likely want to run in a new cable as Sara H is quite right when she says it is a “bodge job” and in consideration of the dangers involved I wish now I had not told you it was possible.
Eric
ericmark

Display posts from previous
Sort by
Order by



  • DIY How to Project Guides

  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!



 


  • Related Topics