Soffit Lighting

[skiking]

Back to my soffit lighting – please bare with me - as you can see I even more useless at electrics than anything else . I am only wanting to lay the cable not the final connection.

My questions are :-
1) Can I run a cable down the wall cavity – this saves me chasing out my recently plastered wall.
2) Can I put in a junction box outside (something like this) within the soffit void that is not going to be accessible without the guttering, fascia and soffit being removed i.e never!

3) In this diagram have I got the wiring layout correct, especially how the lights are wired in.

[ultimatehandyman]

1) Can I run a cable down the wall cavity – this saves me chasing out my recently plastered wall.
2) Can I put in a junction box outside (something like this) within the soffit void that is not going to be accessible without the guttering, fascia and soffit being removed i.e never!

1. I don't know if there is a regulation against this but many sparks are not keen on the idea.

Have you considered D line trunking?

I used some of this the other day and it is good stuff and looks quite smart - http://www.d-line-it.co.uk/index.php?pageKey=7

2. I'm almost certain that any junction box needs to be accessible.

Why don't you put the junction box in the ceiling void with the other junction box?

[skiking]

Cheers for the comments UHM

Chasing out is an option if there are very good reasons for not putting it into the cavity.

I want to avoid at all costs anything on the surface of the wall and I'm not a fan of trunking in the setting I am trying to acheive.

The reason for the the junction box being in the soffit void is so that I don't have to run the cable back to the junction box unless its possible take a single wire (live) down from the source (existing junction box) to the Com terminal and another one (switched live) from the L1 terninal to the lights - told you I know nowt about electrics

[ultimatehandyman]

Cheers for the comments UHM

Chasing out is an option if there are very good reasons for not putting it into the cavity.

I want to avoid at all costs anything on the surface of the wall and I'm not a fan of trunking in the setting I am trying to acheive.

The reason for the the junction box being in the soffit void is so that I don't have to run the cable back to the junction box unless its possible take a single wire (live) down from the source (existing junction box) to the Com terminal and another one (switched live) from the L1 terninal to the lights - told you I know nowt about electrics

Bit confused by your last comment

You can't run single wires unless they are in something to protect them, such as conduit and so you would have to run a cable (twin and earth) as you will need an earth as well.

[Hoovie]

A lot of sparks end up dropping cables in cavities in Conservatories with a brick inner wall to avoid cables on show, so can't imagine why you can't do same in main house wall
I am sure that is how timber framed houses are wired up anyway.

You would probably want to get the cable fairly taut to maintain a good vertical drop down the wall.

I have seen cabling outside lots of times, so it is *probably* ok - once a cable goes outside, it may be subject to a "needs RCD protection" reg?

[skiking]

This is what I was refering to (first pic) when I said about a single wire. I take it this is not allowed then.

The second picture shows how I think it should be done if an internal/accessible junction box should be maintained. The reason I didn't want to go this way was the need to run a 4 mtr length from the new junction box to the switch then another 4 mtrs out to the lights.

[skiking]

Hoovie - this cable technically won't be outside as it is going up into the soffet void. I just wanted to use an external junction box to be on the safe side as I am for the downlights altho' I'd like to think this area won't be exposed to any rain

[Hoovie]

Sounds like a sensible precation

[ultimatehandyman]

I get what you mean now but I think you are making it more difficult than it really is by doing it that way and so I have made some changes, so that you can use single cables of twin and earth-

So from your first junction box you have picked up the live and neutral and earth.

Live into first terminal and live to switch in first terminal.

Second terminal has blue wire from switch sleeved brown (switched live) and live wire to soffit lights.

Third terminal has neutral from first junction box and neutral from soffit lights.

All earths can be put together in one terminal connector inside of the junction box unless you get one with 4 terminals.

[ultimatehandyman]

didn't see your second attachment, but that is the same way as what I have drawn, but different terminals have been used.

Lighting cable is only cheap and 4 metres of the stuff will cost a few quid tops.

[skiking]

Cheers

For a minute I was doing spot the difference - I was concerned there was a subtle difference that I couldn't spot then I read your second post...thanks for taking the time to draw it out.

I should have enough of both 1mm and 1.5mm to complete the job. Will 1mm be OK ?

[ultimatehandyman]

Cheers

For a minute I was doing spot the difference - I was concerned there was a subtle difference that I couldn't spot then I read your second post...thanks for taking the time to draw it out.

I should have enough of both 1mm and 1.5mm to complete the job. Will 1mm be OK ?

1mm is the norm in most lighting circuits, do you know the load of the soffit lights and what size fuse/mcb is currently protecting your lighting circuit?

[Rich-Ando]

try not to mix up the cable sizes in new installations though. ie. if you start wiring from the extisting JB to the new one in 1.5mm cable, do not wire the lights from that in 1.00mm cable. it is bad practice.

personally i never use 1.00mm cable, i always use 1.5mm but 1.00 is fine.
a20Amp 6-terminal JB will be able to handle feed/switch wire & 3 lights and will give you all the terminals you need.

[skiking]

Thanks guys, really apreciate the advice , now to hack off my new plaster, well, when the missus has gone out