adding a outside light to a hall switch

[westsidelodge]

i wonder can you help me ?

i have switch at bottom of stairs which controls stairs and landing .
it has to switches / inside it has 2XL1 2XL2 2Xcom , there two seperate lots of wires each having 1Xblack 1Xred ...then the earth plain wire attached to screw at back .

I would like to add a outside light to this , if possible using this switch ? can this be done & how ?

Thank you

 

[ban-all-sheds]

Yes.

Ignore the switch - you cannot connect the outside light to that, as there is no neutral there.

You need to cable the outside light to the ceiling rose in the hallway (I assume you want the outside light to come on at the same time as the indoor downstairs light?).

Connect the neutral to one of the neutrals in the rose, the live to the live feed for the actual light, and the earth to the other earths.

If your hall light doesn't actually have a ceiling rose then just connect the L,N,E terminals of the light to the corresponding ones on the outside light.

Use 1.5mm twin & earth cable.

A bit more advice:

1) Familiarise yourself with how ceiling roses are all wired up so that you don't get agitated when you unscrew it and find up to 11 wires connected in it:

Basically you need to connect the new light in to the same places as the flex (brown & blue) is shown in the diagram above.

This diagram shows more logically how it all hangs together:

Note that your switch cables are red/black, not red/red. This is more common. The black (switched live) conductor should be marked with red tape or red sleeving to indicate that it is not a neutral wire, but this is often not done.


2) Think about whether you really want the outside light to only be on when the hall light is on inside. If you go out in the morning, do you really want to leave both lights burning all day so that you can benefit from the outside light when you get back in the evening?

 

[westsidelodge]

thank you .

You were saying about light being on at same time as hall (inside) light , is it very differcult give this a new switch of its own ?

I understand all of what you have said , i think the lines of havin light or day does seem a bit silly .

Thank you very much for your prompt rely .

S

 

[ban-all-sheds]

Conceptually I do not believe that it is a difficult task, but from a practical viewpoint I do not know what physical difficulties you would face when installing the new cables.

Does the second diagram above make sense to you? Do you look it and think "Ah, that's how it all works", and can you see what needs to be done? i.e. could you draw on a piece of paper the new wiring that you need to install?

If so, then the difficulties you will face are purely those of physical installation.

If not, then you will probably need to do a bit more reading, and looking at the real thing in your house, before you have a go. It isn't rocket science, but if you want the job done this weekend, and you currently don't have a clue what to do, then I fear you may struggle, and you might be better advised to get an electrician in.

But if you do want to learn, then those diagrams came from here

There's also this which describes adding a wall light with its own switch, so the equivalent to what you need to do.

This DIY-er's site is a good one: here

And finally there are a number of useful books - I can't recommend any from personal experience, but the Collins DIY encyclopaedia and the Which? Book of Wiring and Lighting are frequently recommended by others.


Returning to your job, you will need to break into the lighting circuit at a particular point, and put in a 4-way junction box so that you can run a new cable down to a new switch (which could be completely new, or you could replace your existing 2-gang switch with a 3-gang). So the 4 terminals in the JB would be Live, Neutral and Earth, coming in and going out, with the switch cable connected to Live and the 4th terminal (and of course earth for the metal box), and the outside light connected to the 4th terminal, Neutral, and Earth if it has one. (if it doesn't, connect it anyway at the JB for protection, and at the light just make the wire safe somehow - don't cut it back in case someone needs it in the future. Same goes if you have a plastic box for the switch and don't actually need to earth it).

[I don't know if you are allowed to use the terminals in an existing rose for a completely separate light and switch - maybe someone who knows the regs can advise on that]

If it isn't very obvious to you what you need to do, then I don't think you are ready yet to DIY.

You will need to lift floorboards to get access to the wiring, you will need to identify which cables are which (a multimeter or some voltage indicating device is almost essential), and you will probably need to chase a channel in the wall to take the new switch cable (in conduit or under capping), and sink a hole for the box if you are using a separate switch. If you use a 3-gang in place of the current 2-gang, count yourself very lucky indeed if you are able to get the new switch cable down the same run as the existing ones.

And don't forget all the motherhood-and-apple-pie stuff about turning off the power, making sketches, labelling cables, all the earth wires should be properly sleeved in green/yellow, and the switched live should be marked with red tape or red sleeving.

And good luck!

 

[westsidelodge]

hi...just a quicky to say thank you , basically i did as you said about wiring to rose in hall , my a good job even if i do say so myself , wires hidden in floor board too .

All working , light in hall & outside light come on together , feel i took easy option , but didnt feel confident about separate just yet , bit more studying needed.

 

[ban-all-sheds]

Excellent - I'm glad you got it going, and thanks for returning here and letting us know how you got on.

And your attitude at the end is safe one.