Looking for some help/advice on fitting outdoor lights with armoured cable.

[strin]

Hi,

We have a retaining wall in the garden on the edge of our patio. Our electrician has run some armoured cable behind the wall, coming through at regular intervals for the lights (the cable will eventually be buried by the earth the wall is holding back).

The trouble is, the cable he has used seems to be really restricting the choice of lights we can use.

The cable is stamped with 600/1000v BS5467 h nexans 3x1.5. After some Googling, I found the following specification for the cable:
CU/XLPE/SWA/PVC BS 5467 3x1,5 mm2 - Nexans - https://www.nexans.co.uk/eservice/UK-en_GB/navigateproduct_540168747/CU_XLPE_SWA_PVC_BS_5467_3x1_5_mm2.html#

This says the cable has an outer diameter of 12mm, and as we need ingress/egress for 2 cables, I am guessing that the spigot is going to have to be 24mm (possibly larger?).

However, I'm being told we need to allow for 80mm, and as a result the proposed light fitting is too industrial (looks like a light on a shower block in a camp-site - not quite the look we're going for). So my questions are:

- do we really need an 80mm spigot for 2nox12mm cables?
- if not, what's the minimum size spigot we should be looking for on the fitting?
- is there any way to use an external, IP65, armoured junction box on the back of the wall (which will eventually be underground) to reduce the size of the cables required to go in/out of the light fitting?
- finally, can anyone recommend any suppliers of light fittings for such a setup?

Thanks in advance!

 

[davesparks]

The diameter of the cable isn’t the issue, it’s the cable glands which are used to terminate the cable which are much bigger than the cable itself.

Yes it is possible to joint the cables on the back of the wall, but this needs careful consideration of the type of joint to be used as it is being buried and will partly come down to the preference of the electrician doing the work.

 

[Wilko]

Hi - Hopefully you will be comforted to know that steel wired armoured cable is rugged and is the best to use outside where it might be hit with a spade or some such. You are going to need help to do this properly .

 

[Pete999]

Hi - Hopefully you will be comforted to know that steel wired armoured cable is rugged and is the best to use outside where it might be hit with a spade or some such. You are going to need help to do this properly .

What he said^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 

[telectrix]

what he said about what he#1 said ^^^^^^.

 

[sham]

Yhea, what they said ^^^^^

 

[Pete999]

what he said about what he#1 said ^^^^^^.

You didn't say anything did you?

 

[sham]

My friend, I am going to be honest with you. You do not trust the electrician as you are doing some research behind his back. I do not even know what a spigot is. Armoured cable, to me is professional and you can install any light from the joint box. Most lights are LED now so you should not have a problem with power. Sometimes the cost and materials can put the customer off. But if I was buying a property and I saw armoured cables to outside fixtures, I would feel that the people of the house have pride.

 

[Midwest]

I've never fitted any luminaires to be installed in bricks walls, but I've come across some that have, and when they have failed. Covering them and all their joints, will inevitably result in premature failure of your lighting system, the cables will be fine, its just the fittings & the joints/terminations.

There are some suitably rated joint boxes;

Wagobox-Capsule IP68 Adaptable Junction Box - Grey - https://www.connexbox.com/shop/wagobox-capsule-ip68-adaptable-junction-box-grey.html

but ultimately the luminaire will fail, and you'll need access to the joint to replace them. That part of the install needs some consideration, by you or your electrician

 

[strin]

My friend, I am going to be honest with you. You do not trust the electrician as you are doing some research behind his back. I do not even know what a spigot is. Armoured cable, to me is professional and you can install any light from the joint box. Most lights are LED now so you should not have a problem with power. Sometimes the cost and materials can put the customer off. But if I was buying a property and I saw armoured cables to outside fixtures, I would feel that the people of the house have pride.

Thanks all for the swift replies - it's certainly not that I don't trust him, he has wired the whole house for us and has done a brilliant job (it's a new build), but I guess I'm just frustrated that we are so limited in the choice of fittings. Absolutely agree/am pleased with the use of armoured cable, I was just keen to see if there were any options out there that would allow a broader choice of fitting - but seems like we truly are limited. Will keep searching for any other fittings that might be work with this cable and the glands it will require.
I thought 'spigot' was the correct term for the entry point into the back of the light fitting - obviously not! Thanks again all for your input.

 

[sham]

Thanks all for the swift replies - it's certainly not that I don't trust him, he has wired the whole house for us and has done a brilliant job (it's a new build), but I guess I'm just frustrated that we are so limited in the choice of fittings. Absolutely agree/am pleased with the use of armoured cable, I was just keen to see if there were any options out there that would allow a broader choice of fitting - but seems like we truly are limited. Will keep searching for any other fittings that might be work with this cable and the glands it will require.
I thought 'spigot' was the correct term for the entry point into the back of the light fitting - obviously not! Thanks again all for your input.

No sorry, I'm could be wrong about the word spigot, it just I never heard of it. It could be the correct term. I get lost easily, are these lights you are talking about for embedding in a wall as in brick lights.

 

[Pete999]

No sorry, I'm could be wrong about the word spigot, it just I never heard of it. It could be the correct term. I get lost easily, are these lights you are talking about for embedding in a wall as in brick lights.

A spike for banging into the earth to hold up something, ie a garden light

 

[strin]

No sorry, I'm could be wrong about the word spigot, it just I never heard of it. It could be the correct term. I get lost easily, are these lights you are talking about for embedding in a wall as in brick lights.

No - they're to be surface mounted about 1 meter above ground level, with the cable coming through the wall. I don't believe there will be a junction box, hence the problem with the cable diameter and resulting cable glands.

 

[strin]

A spike for banging into the earth to hold up something, ie a garden light

Definition of spigot - a small peg or plug, especially for insertion into the vent of a cask., a tap., the plain end of a section of a pipe fitting into.

Looks like I got completely the wrong word

 

[sham]

A spike for banging into the earth to hold up something, ie a garden light

Thank you very much Pete.

 

[strin]

The diameter of the cable isn’t the issue, it’s the cable glands which are used to terminate the cable which are much bigger than the cable itself.

Yes it is possible to joint the cables on the back of the wall, but this needs careful consideration of the type of joint to be used as it is being buried and will partly come down to the preference of the electrician doing the work.

Thanks - so would each cable (in/out) require an individual cable gland, or is there a means by which a bigger gland would cater for both cables. Just wondering how I figure out the size of the gland(s) required if the cable diameter is 12mm?

 

[Octopus]

Why don’t you ask the spark who installed it?

 

[telectrix]

normally, the SWA cable/s gland into a wiska (or similar) box, then jointed in there to a suitable flex to the light.

 

[telectrix]

Thanks - so would each cable (in/out) require an individual cable gland, or is there a means by which a bigger gland would cater for both cables. Just wondering how I figure out the size of the gland(s) required if the cable diameter is 12mm?

20mm glands.1 for each. wiska boxes are pre drilled and threaded exactly for this.

 

[Strima]

As Telectrix has mentioned, armoured cable glanded into a suitable box then flexible cable fly-lead off to your luminaire.

Either a conduit or Pratley box is a start.