two way switching with twin and earth

[wps7581]

hi Guys,

i have recently moved a two way switch across the other side of the room, they now only work if the downstairs light is switched on first, it is basically a standard set up with the stairway light one switch at the bottom one at the top. now i always assumed you needed three core and earth for this but apparently not. i have i believe the old way of wiring two way sockets. i fully understand how to convert from one way to two way using three core and earth but how can integrate it into this system, because the cables runs and boxes are plastered in so i cant do a new cable run, basically i have three wires at both switches downstairs i have a single neutral (not tagged so this doesn't help) and the usual red black and unsleeved earth and upstairs i have a single red and the red black and unsleeved earth, testing the cables it seems that both switch sides as they should in two way mode, i,e the live then the neutral both carry the voltage, but i am struggling to find the feed cable help me please!!!

 

[dingbat]

Calm down (slap!)!

Now, breathe deeply and check out the thread at the top of the forum - the one entitled Read Here First - FAQ - For reference.

If, after reading the posts and studying the [plentiful] diagrams you still don't know how to do it, you need a professional.

 

[Qedelec]

Hey Ding, wots a diagram?????

 

[dingbat]

Twice as big as a monogram?

 

[Qedelec]

Rofl.......

 

[wps7581]

you guys are really helpful fools!!!

 

[dingbat]

you guys are really helpful fools!!!

Okay wps, how about you ask your question in English and we'll try to help?

Halfway through your post it was clear that you don't understand, or lack the ability to describe, what you have/need. I gave you the benefit of the doubt and directed you to the top of the forum where you will find all the information you need. If you can't follow that then I don't see how snapping back will help.

I do hope you find a solution to whatever it is you were asking.

 

[wps7581]

and your blatant sarcasm is a great help the whole idea of this forum is to provide help one day perhaps i will be as wonderful as you.

thanks for your help

 

[dingbat]

You should try asking your question on Screwfix if you like sarcasm.

Seriously, if you can't work out from the FAQs how to go about solving your problem you really should not be messing about with electricity.

 

[fr1day]

wps> as a newbie to the forum and someone who has been asking questions myself maybe I can intervene here.

You're first post doesn't quite make sense. The sentences run into each other, and the explanation of the wiring isn't very clear. After reading the FAQ maybe you could set out the question more simply for all to read.

 

[securespark]

A BIG hint..

Usually, the twin & earth is the strappers and the single the common or switchwire.

Now, if that doesn't help, you do need some.

 

[wps7581]

Ok point taken, if i snapped a little please accept my apologies,

i fully understand that the twin and earth should be the strappers, and the singles the common or switching wire, so a theoretical question? if i conected one of the strappers into the common, and the feed cable into L1for example, would this manifest itself as the problem i have? that being that the upstairs switch will only work if the downstairs switch is on?

thanks

 

[dingbat]

Assuming that you have not had to extend the cables (i.e. that you have simply re-routed them) and that you have not inadvertently lost any, this should be simple.

You don't have any neutrals at either of these switches - every core except the earths will be classed as live. The usual thing to find would be that the twin and earth cable is used for strappers - they connect between each switch L1 to L1, L2 to L2.

Of the two single cores, one carries the permanent live to the first switch and the other carries the switched output from the second switch to the light. These will be both connected to the Common terminals.

Unless you have cables there you haven't described you shouldn't have any problem.

 

[dingbat]

if i conected one of the strappers into the common, and the feed cable into L1for example, would this manifest itself as the problem i have? that being that the upstairs switch will only work if the downstairs switch is on?

Yes.

 

[wps7581]

hi Dingbat,

that was my thinking but i have had to join the cables, i have crimped then amalgamated then, exactly as they were at the switch, will this cause the fault? i.e the single black crimped to single black, and the strappers red to red black to black and earth the earthing point.