Cable for outdoor security lights

[toastydave]

Hi All,

I currently have a security lamp, with integrated PIR over my back door, on a switched fused spur, this came with the house (new build 2001).

I want to replace this single light, (like this http://www.screwfix.com/prods/39450...eads/Rectangular-60W-Black-Bulkhead-with-PIR) with a separate PIR and 5 Circular Wall Lights like this http://www.screwfix.com/prods/22514...-Lighting/Stainless-Steel-Circular-Wall-Light along the wall, to illuminate a pathway along side my house.

Total load even with incandescent bulbs would be no greater than 300W.

I understand how to wire the lights up, and I know I will run into part P, so I want to do the work and get a electrician to come and sign it off.

With this in mind, what kind of cable do I need (it will run along the outside wall) to interconnect the lights, as it will be 8ft of the ground, do I still need to use SWA cable, if not do I need to run it in conduit?

Anybody know what the 17th ed has to say about this?

Thanks

 

[flameport]

I want to do the work and get a electrician to come and sign it off.

Not going to happen. The only two legal options are:

1. notify building control and pay their fee before starting, and then do the work yourself
2. pay a member of a competent persons scheme to do the work and notification.

 

[ban-all-sheds]

Circular Wall Lights like this http://www.screwfix.com/prods/22514...-Lighting/Stainless-Steel-Circular-Wall-Light

http://www.google.co.uk/products?hl...esult_group&ct=title&resnum=3&ved=0CDIQrQQwAg

With this in mind, what kind of cable do I need (it will run along the outside wall) to interconnect the lights,

Is there no way to run the cables internally? It would look soooooo much better. The lights are probably designed to have the cable enter through the rear anyway.

as it will be 8ft of the ground, do I still need to use SWA cable, if not do I need to run it in conduit?

You're unlikely to need either, unless you know of factors which mean the cable could get damaged.

Neither would terminate well into those lights. Black TRS (tough rubber sheath) would almost certainly be OK, but it'll be very hard to get the runs dead straight, no drooping etc.

From an appearance POV the best cable to use if it must be external would be stainless steel MICC, but the words "expensive", "impractical" and "hard to find an installer with the skills to do it" spring to mind.

Anybody know what the 17th ed has to say about this?

Basically that cables (and anything else) must be suitable for the environment they will be in, taking account of external influences such as impact, abrasion, vibration, heat, corrosive atmospheres etc.

 

[toastydave]

http://www.google.co.uk/products?hl...oup&ct=title&resnum=3&ved=0CDIQrQQwAg[/QUOTE]

They look much better thanks!

Is there no way to run the cables internally? It would look soooooo much better. The lights are probably designed to have the cable enter through the rear anyway.

Yes it would be my preference too, not without lots of work, I could probably get away with running 3 out of the 5 internally

I seem to remember from somewhere that even if the lights are outside but the cable run is inside, its no longer part P.... is this still right?

Thanks for your help, just what I needed!

 

[holmslaw]

..

 

[ban-all-sheds]

I seem to remember from somewhere that even if the lights are outside but the cable run is inside, its no longer part P.... is this still right?

No - Part P applies to any work whatsoever on fixed electrical cables or fixed electrical equipment located on the consumer’s side of the electricity supply meter which operate at low or extra-low voltage and are—
(a) in or attached to a dwelling;
(b) in the common parts of a building serving one or more dwellings, but excluding power supplies to lifts;
(c) in a building that receives its electricity from a source located within or shared with a dwelling; or
(d) in a garden or in or on land associated with a building where the electricity is from a source located within or shared with a dwelling.

In terms of notification then strictly speaking these lights would be notifiable however you cabled them up, but for some reason the Approved Document says they aren't if the cables are not external, so it would be churlish to refuse to agree with that, wrong as it is.

 

[ban-all-sheds]

The words 'no such thing as stainless micc wiring cable' spring to mind.

Ah - well, I initially thought about MICC, and wondered, "can you get it in SS?". Seemed a reasonable idea - there must be environments where copper would be no good - it's not the strongest or most corrosion-resistant metal in the world....

And lo -

"MICC Ltd is Europe's largest provider of stainless steel mineral insulated cable."

But I didn't look closely enough - their products are thermocouple and trace heating, not power.

A bit more digging shows (AFAICT) that you can get MICC with an Alloy 825 outer, which would tick the cosmetic box.


Wouldn't Hituf have too poor a bend radius?

 

[holmslaw]

..

 

[toastydave]

So...

I think I will run 3 out of the 5 from the inside on a separate circuit as I can get to the back of the wall for three of them.

Two are going to have to be surface mounted (one with feed from behind and then a spur to connect to the second)

To facilitate this I will make two wood plinths (one for each light) with channels routered into them for cable run between the two lights and of course something to mount the light on.

Thanks all for your help!

Dave