2-way light switch query

[Mike]

Can anyone explain how to wire up this 2-way switching?

The existing setup: A lounge with one ceiling light controlled by one wall switch. Cables are twin & earth.

What I want to do is run a cable from the *ceiling rose* in the lounge to an existing light switch in a hallway leading off from the lounge.

I then want to replace the hall switch with a dual-gang switch. I want one side of the new hall switch to control the hall light, and the other side to control the lounge light. The original lounge switch must behave as before: switching the lounge light on and off.

I'm guessing this is dead simple to do, but would be very grateful for a link to the relevant wiring diagram, or alternatively, worded instructions. Thank you in anticipation...

An alternative solution would be to run a cable from the lounge ceiling rose to a second single-gang switch in the same room, so each of teh two switches in teh room can then turn the light on and off.

Mike F

[Andy Burns]

that might be what you want, but it isn't what you need ;-) what you need, is a three core and earth cable between the existing lounge switch and the existing hallway switch.

look at the "alternative" method described here

I'm guessing this is dead simple to do, but would be very grateful for

all your other suggestions would require replacing your wxisting twin and earth cables

[Colin Wilson]

I might be barking up the wrong tree here, so wait to see if there are any more elegant answers :-}

How many T&Es are in the existing switch ? (unless there are two, I think this might be a non-starter - and even then...)

Basically you're looking to try to get this:

switch1 ___/--------------------\____ switch2 live from lamp \--------------------/ switch to lamp * ...but you need a spare core to the first switch to act as the "strap" to the second switch as you're wiring from the centre* not end to end.

Then, if you can get a three-core&earth to the second switch from the ceiling rose, two cores are the strap wires, the third being the switched live - you can hopefully get creative with a connector strip :-}

I wonder if anyone makes a more elegant solution in that the second switch doesn't need wiring at all - it'd be a battery powered RF device that signals the other to switch electronically...

[Owain]

I think one of the TLC wireless switches will do this.

Owain

[Dave Plowman (News)]

The switch circuit from the ceiling rose to the existing wall switch consists of two wires (excluding earth). For two-way you need three.

Two-way switch A Two-way switch B

L1 L1 0===========0 0===========0============= Line | \ / | C 0================================O C \ / \ / 0===========0 0===========0============= Switch return L2 Optional L2 Intermediate Switch

Still won't work, I'm afraid.

[dennis]

If you don't understand it and don't want to run three core + E cable between the switch points you can use RF switches to do the job.

has a selection of them (they may be cheaper elsewhere).

It also avoids any Part P problems as you aren't doing any new circuits.

[dennis]

I forgot its cheaper using X10 but more prone to interference YMMV.

[John Rumm]

It would be a minor work in this case, since it is extending and existing circuit and not in a special location or kitchen.

[Mike]

There is only one T&E from the existing switch. However, it would be easy to add extra cable(s) going from the rose to the hall switch, as the hall switch wires run down inside a wall cavity. (No chasing required)

I'll look into those. Thanks for the suggestion. Thanks also to the others who responded.

Mike

[Mike]

Thanks for the suggestion. I looked at the X10 switches at the above URL, and could not find any mention of wireless control. Perhaps I am missing something.

If I go for some kind of wireless switching, I'd like something that could replace the existing lounge switch, such that I could have a second switch that could override the new lounge switch by wireless means. Can anyone post a link to such a pair of devices?

Mike

[Andy Burns]

As the existing cable from rose to lounge switch is only 2core and earth you can't get 2-way switching without either

1) Adding a new 3core and earth cable between the hall and lounge switches.

or

2) Replacing the existing cable from rose to lounge switch with 3core and earth, and adding a new 3core and earth from rose to hall switch, but you'll probably have 16 wires to terminate in the rose.

or

3) Investigate the wireless switch option.

[Mike]

Sorry - half the problem was that I didn't understand what X10 was.

explains more about X10 switches. I'm still trying to figure out exactly which components I'd need to do the job.

Mike

[dennis]

You need three bits of X10.

One switch to replace the existing switch plate Part no: 10031 on the link above (note that this is a dimmer and doesn't work with fluorescents, LV halogens.. use 10030 which is just a switch but may need a neutral wire running) There are other X10 modules that fit bayonet sockets and 13A sockets if you look around).

One RF switch

one RF receiver RF receiver is also a switch unit which can be operated by the RF switch above.

[Mike]

On reading further, (if I understand the description correctly), the "X10 2-way switch bundle" at:

appears to do exactly what I need. I presume that no batteries are required with these, which seems a definite plus.

Mike

[dennis]

There is a battery in the unit with the buttons. They last a couple of years IME.

[Mike]

Many thanks! The offerings at the above URLs seem a lot cheaper than others I was looking at.

Mike

[Mike]

Yes, I realise in retrospect that one item would need a battery. Not really a problem, especially if they last a couple of years.

It sounds like you have 1st-hand experience of these devices. Have you noted any problems?

Thans again,

Mike

[dennis]

I built a home automation demonstration for the company I worked for. It worked fine but it was problematic in that I was working in an industrial environment using power rails that were on different phases. X10 doesn't cross phases so I had to rearrange a lot of the under floor outlets to get it to work.

Once it was working it could be controlled using a flash application running over the web and included AV, TVoD, etc. I use homeseer software for the basic control as it has a programming interface.

[Mike]

Hi, Thanks for the input. Could you please clarify... if I install an x10 dimmer switch in place of the regular light switch in my lounge, would that be notifiable if I do it myself? If so, I'm rather amazed.

Mike

[John Rumm]

It would not be notifiable. The stuff that is notifiable includes things like running complete new circuits from the consumer unit (CU), changing the CU, or extending existing circuits in bathrooms. Even "like for like" replacements of switches in bathrooms is permitted as a minor work.