Moditying Lighting switches to 2 Way

[alan8376]

I have a big room with 2 lights on the ceiling and a door at each end of the room. One light can be switched on only and from a one switch (no 2way).

What I want to do is fit a 2 way switch near each door, at the same time modifying both lights to illuminate at the same time from either switch.

I am aware of the later wiring method of running a 4 core cable between the 2 switches with an additional cable running up to the light from one of the 2 switches.

Now this is my problem. I don't think I am going to be able to feed the 2 cables up inside the wall without chasing out the one switch!

Else where in my 40 yr bungalow, it appears a 2 way switch has been achieved with just a 2nd wire! I am sure there is room to feed 2nd wire up inside the original channel without resorting to chasing out?

Can anyone advise me of the circuit diagram that has been used?

Thanks
Alan

 

[holmslaw]

..

 

[sparkwright]

If you can re-use existing conduit drops, you can achieve what you want with just one 3 core+earth cable at each switch.

You would have to do one or two big joints in the loft.

Note;
What you refer to as 4 core cable should be 3 core+earth cable - brown, black, grey, earth.

2 core+earth - brown, blue, earth.

 

[alan8376]

Thanks,
I did mean 3core+earth when saying 4 core cable.

Thanks for the tips
Alan

 

[Stoday]

There are two main methods of wiring 2-way switches, using three strappers or two strappers.

3 Strappers Uses 3 core (+E) cable to strap the commons and the two sets of L's. Live feed and switch wire connected to the L strappers.
Advantages: Live and switch wires may be connected to the two L strappers anywhere along the 3-core's route; Minimised RFI.

2 Strappers Uses 2 core (+E) cable to strap the two sets of L's. Live feed connected to the common of one switch, switch wire to the common of the other.
Advantage: May be possible to convert one way switch more easily than the 3 strap method.