Replacing existing single outside light with THREE

[scrid]

Dear all,

I'm looking for a little help on correctly adding a external light.

I currently have a single outside light that I want to replace with 2 lights at either side of the front door, and also a security light with PIR inside the porch that would illuminate the front door if someone came to the door.

I was assuming that I simply need an external junction box using the existing cable and run extra cabling through to the 3 new lights.

Is this right, is it as simple as I'm assuming? Any help with the right wiring and any links to specific junction boxes would be gratefully received.

Thanks!

 

[riveralt]

It will depend how your current outside light is wired. I assume it operates on single switch inside.
It is possible that the current outside light may be wired with live and switch live whereas your PIR and probably your new lights will be looking for live, neutral and earth. If this is the case then you will need to start the wiring again.

Have a look at wiki under lighting here:
//www.diynot.com/wiki/electrics:lighting

If you do have live, neutral and earth at the current light then you would run additional cable from this light to next and the PIR as per manufacturers instructions.

 

[Alarm]

Would this then not become notifiable?

 

[scrid]

Thanks for your response riveralt.

Yes, the existing light runs off a switch in the hallway. I will check if the existing outside light has L,N&E running to it. If so, I was planning to use something like this: http://cpc.farnell.com/hensel/kx2025/enclosure-ex-88x88x53mm/dp/EN82566 - would that be the right type of unit?

Alarm - Thanks for the prompt. If it needs rewiring, I won't be doing it! So that'll be a call to a qualified electrician in any case.

 

[riveralt]

Yes that would do, if a little over the top - remember your lighting unit will act as a junction box and most outside lights are made to IP44 standards.
So if the MI allow you would run outside rated cable (rubber or tuff) from your first light to your second and onto your PIR light.
You just need L,N and E arriving at your first light.

Regarding Alarm's comment, there has been some debate about the interpretation of the building regulations regarding replacing like for like (in its broadest or narrowest) terms and when there is a requirement to notify.
In the example you give, whether you have LNE at the first light or not I would notify because the circuit has been extended - but then it only costs me £2.50 to notify.

 

[ban-all-sheds]

Regarding Alarm's comment, there has been some debate about the interpretation of the building regulations regarding replacing like for like.

Yup - often involving people who simply will not let go of the false notion that the Building Regulations make any mention of the concept of "like for like".

 

[riveralt]

Regarding Alarm's comment, there has been some debate about the interpretation of the building regulations regarding replacing like for like.

Yup - often involving people who simply will not let go of the false notion that the Building Regulations make any mention of the concept of "like for like".

Ah don't you just love fishing, cast a small piece of bait and the big bass fish bites every time.

 

[ban-all-sheds]

My apologies - I hadn't realised that you were a pathetic and inadequate little child with an ulterior motive behind your post.

I must remember in the future to always assume you are.

 

[riveralt]

My apologies - I hadn't realised that you were a pathetic and inadequate little child with an ulterior motive behind your post.

I must remember in the future to always assume you are.

No need to apologise BAS, everyone knows you don't mean it.

 

[PrenticeBoyofDerry]

If the lights are mounted to the outside of the house and there are no exposed connections and does not involve installing a new circuit and the circuit that is being altered, does not extends a circuit from a kitchen or other associated special locations.
As I understand it, you don't need to notify the work.
Like for like it or not

 

[scrid]

So if the MI allow you would run outside rated cable (rubber or tuff) from your first light to your second and onto your PIR light.
You just need L,N and E arriving at your first light

The reason for choosing that junction box was that I thought I would be running a separate cable from it to each light individually. So 1 cable in and then 3 cables out of the junction box. From your quote above, that would be wrong, and I should run all of the three lights in line, is that right?

 

[riveralt]

So if the MI allow you would run outside rated cable (rubber or tuff) from your first light to your second and onto your PIR light.
You just need L,N and E arriving at your first light

The reason for choosing that junction box was that I thought I would be running a separate cable from it to each light individually. So 1 cable in and then 3 cables out of the junction box. From your quote above, that would be wrong, and I should run all of the three lights in line, is that right?

As I said it will in part depend on the manufacturers instructions for each lamp, what the current wiring arrangement is and how you want the new lights to operate..
If you do have LNE at the switch then you should have Switch Live, N & E at the old light.
You then need to decide how set up the new lights. If you intend to have the two new outside wall lights operated by the inside switch then at the first lamp put the SL in the live terminal, N in the neutral terminal if Earth in the earth terminal. Then loop new wire from the first lamp's SL, N and E to the second lamp. This way the inside switch will operate both lights.
For your PIR lamp, you need L, N & E at the lamp so you have get a cable from the inside switch's LNE to the PIR lamp's LNE.
The alternative, is to run the L, N & E to the PIR then loop out to the other two lights (provided the PIR lets you) That way when you PIR light activates so will your other two outside lights.
The third way is to use the JB as you suggested to each lamp individually. Still assuming you want the inside switch to operate the two outside wall lights - then you would run three core and earth from the switch to the JB. One core would be the Permanent Live, one the switch live, one the neutral and the earth. At the JB you would connect cables to the SL, N and E and onto your two outside lights. At the JB you would connect a Permanent L, N & E cable to the PIR light.

 

[scrid]

Thanks for specifiying it in such great detail. That's clear and I'll do it how you suggest. I'll check this weekend that the existing light has the LNE, which I think it does looking at the cable that runs into it.

So if the MI allow you would run outside rated cable (rubber or tuff) from your first light to your second and onto your PIR light.
You just need L,N and E arriving at your first light.

You mention the need for outside rated cable. Can I use 1.5mm2, such as this: http://www.mr-resistor.co.uk/item.aspx?&t=629&r=631&i=5629&a=1, or do I need the larger 2.5mm2?

Thanks for all your help!

 

[riveralt]

You mention the need for outside rated cable. Can I use 1.5mm2, such as this: http://www.mr-resistor.co.uk/item.aspx?&t=629&r=631&i=5629&a=1, or do I need the larger 2.5mm2?

Thanks for all your help!

For a lighting circuit the 1.5mm2 is more than adequate. The key issue is that the cable has a current carrying capacity greater than the rating of the fuse/MCB protecting the circuit - which for a lighting circuit is normally 5/6Amps.

To help identify whether you have LNE at the switch you would normally have a terminal block inside the switch with the netural cables as outlined here in wiki.
//www.diynot.com/wiki/electrics:lighting:single_way_lighting:tblsnonharm

 

[SimonH2]

If the lights are mounted to the outside of the house and there are no exposed connections and does not involve installing a new circuit and the circuit that is being altered, does not extends a circuit from a kitchen or other associated special locations.
As I understand it, you don't need to notify the work.

Yes you do, because an outside lighting installation is "a special installation" even though it is not in a kitchen or special location - Sched 4 para 2b refers does not involve work on a special installation

Para 4 defines a spacial installation as “special installation” means an ... an outdoor lighting or electric power installation ...