Advice on Installing Brick Lights

[rjdainty1]

Hello all,

I've recently begun building a retaining wall in my garden for a patio area, I decided to go for 6 brick lights along with other lighting for the area (not decided exactly what that will look like just yet). The brick lights I went for are these.

I've been having a read up on how best to wire these lights, I have a garage nearby and figured that the 6 x 4.6W lights shouldn't put too much strain on my garage. However wiring them up has got me wondering the best way to do this.

I've fitted lights, smart heating and some other basics around the house but don't have a massive amount of experience. I was hoping that I could find a solution that wouldn't involve me taking six individual runs of cable into the garage and joining them there, but most the solutions I've read about seem to suggest that many outdoor joining solutions will not last due to the elements.

A number of people have mentioned Wiska boxes filled with gel, which sounds great and about my price point but I'm not sure what to do for the best. I'm also a little unsure about the earthing. The garage is about 1m from one part of my wall although I might possibly send the cabling around the outside of the garden which would mean the cable would be a minimum of 10m long.

Do you think the Wiska box solution might be good enough, or should I perhaps just run all wiring into the garage? Or of course, if there's another solution I'd be happy to hear it.

Thanks
Rob

 

[pc1966]

This is the sort of duct davesparks is referring to:

32/40mm Class 3 Electric Cable Black Ducting Coil (50m)

50m 32/40mm black ducting coil for electricity cables in Class 3 applications. With coupler and draw cord.

store.jdpipes.co.uk

You might want to ask around suppliers to see if they have any shorter lengths if, as suspected, you don't need anything like 50m.

Unless you have other garden projects involving underground runs of cables or similar where it would be useful.

 

[rjdainty1]

Thanks again everyone, some really useful comments. So I've measured up the cable lengths and the four cables add up to ~20m (2 + 4 + 6 + 8m).

Looking through the guidance, I was going to go for the following:

• 25m x 3-core 1.5mm2 armoured cable
• 4 x M20 Glands
• 2 x 20mm x 10m Corrugated Conduit

Following a read of this page, I wasn't going to get any heavy duty ducting given the cable type, but if I've misunderstood and you believe this is a mistake please let me know.

I'll then terminate the cables in the garage, put the four into a junction box and into a mains plug (BS1363). Which means I can easily use a smart plug to control. I plan to purchase tomorrow (just to give anyone time to shout "stop" in what I'm buying )

Thanks

 

[davesparks]

Looking through the guidance, I was going to go for the following:

• 25m x 3-core 1.5mm2 armoured cable
• 4 x M20 Glands
• 2 x 20mm x 10m Corrugated Conduit

They are the wrong glands for armoured cable, and you need 8 glands for 4 cables, one at each end of the cable.

 

[pc1966]

Also that duct is not outdoor rated. If you are using SWA then you don't need the duct as it can really be buried in most ground conditions without issue.

But as davesparks has pointed out, you need to use the correct glands for the SWA not just to keep the water out (which the plastic ones do) but also to ensure there is a sound electrical connection to the armor (which also has to be earthed, of course). Also you get SWA glands for indoor and outdoor use, obviously the outdoor type with the additional sealing back should be used on any outdoor connections!

If you use the 3-core wire that you propose, then you can get away with a SWA gland at the garage (power feed end) and using one of the 3 conductors at the CPC (i.e. earth wire) to connect to the lights at the far end (assuming they do need earthed which is most likely), and at the light end you can use a plastic gland. But best practice would be a proper SWA gland at both ends.

Also be aware that most 3 core SWA cable has the phase colors: brown, black, grey

You should sleeve the one you use for neutral with blue (as a normal single phase cable has) and green/yellow for the one you use as earth. Practices vary about which colour to reuse, some go for: grey -sleeve blue for N and black - sleeve green/yellow for earth, other the other way. Whatever you do make it consistent!

Also assembling a SWA gland is a bit trickier than the plastic ones as you need to prepare the armor, etc, but there are several youtube videos showing how it is done. I suspect you have not done it before, so if going down that route then practice first on a bit of wire and a gland that you are not needing.
[automerge]1598456277[/automerge]
Also not the burial depth has to be sensible for the ground use - the 60cm often quoted allows for serious spade work, but on an agricultural field you would look at 1.1m or so. If you know it is never more than an ornamental region lightly troweled then a slightly shallower depth is OK but I would not go much less than 40cm.

 

[Midwest]

If you are using SWA then you don't need the duct as it can really be buried in most ground conditions without issue.

I like wheeling this link out, every time I read that.

 

[pc1966]

Not sure the ground is waterlogged there. Also if it is going in proper outdoor duct then they might as well got for an easier cable to terminate!

 

[Midwest]

Not sure the ground is waterlogged there. Also if it is going in proper outdoor duct then they might as well got for an easier cable to terminate!

Might be after yesterdays storm. I much prefer to install swa in ducting, some nice twin wall.

 

[rjdainty1]

Thanks again all, especially the lengthy post from @pc1966 - thanks.

So following the additional advice, I'm now planning on:

• 25m x 3-core 1.5mm2 armoured cable
• 4 x Exterior Gland Kits
• Enclosure for inside garage

The point about having never done this before - you're quite right. I've just watched a good YouTube video explaining the gland fitting which helped a lot. Every day is a school day with my patio I'm finding.

I'll leave ducting but I'll be sure to bury at least 0.60m.

 

[pc1966]

The enclosure you link to is rather small. You seem to be fitting 4 lights, so will need 5 entry points, one for the main power and the 4*SWA. It would seem more sensible to look at a box that can take 4 SWA glands in a row at the bottom, etc. Many such boxes have knock-outs for 20mm (most common gland size, etc) but if you need to make 20mm holes than the Armeg "acceler8" hole saw does a great job on metal and plastic.

You also need to allow for some joints inside there but 5-way Wago leaver terminals are your friend. Also some ring tags and matching screws to attach to the "banjo" of the SWA gland.

Wago also do a box with a fancy plate to joining up (two, I think) SWA glands but I have never used one.

 

[davesparks]

• 25m x 3-core 1.5mm2 armoured cable
• 4 x Exterior Gland Kits
• Enclosure for inside garage

That enclosure wouldn't be my first choice.

Unless I have a very good reason not to I would always terminate armoured into a metal box. For that number of cables I'd likely go with a 6" adaptable box.
Metal boxes make the earthing connections easier, and tend not to bend so easily when the cable pulls against them.

The other thing missing from the list is an electrician to do the job safely and in compliance with the wiring regulations.

 

[Markyd]

I take it this is a new circuit and if so needs an EIC and notification to Building control

 

[suffolkspark]

Noticed a couple of guys suggesting NYY-J and HO7RNF are suitable for direct burial in this thread ? it's great cable but that's not the case.

Also you mention about needing to declare this work if you sell your house, which is true, but you'll need it tested and certified in any case so why dont you just get an electrician to do this whole job properly?

 

[rjdainty1]

Hello again all,

Okay, following multiple revisions - I'm hoping the list below takes into account the advice most have given:

• 25m x 1.5mm2 3-core SWA
• 25m x 150mm Warning Tile
• 1 x Wiska Box
• 3 x 5-way Wago
• 4 x Gland Kits

Thanks again

 

[rjdainty1]

Morning all,

So installation of the lights has gone pretty well, I went with the kit in my last post. The cable is laid, I’m just about to fill in the trench (I haven’t wired it all into the garage yet but I’ve tested that each light works okay).

I followed a video in how to install SWA cable with the glands, but it wasn’t until I was thinking last night that I realised those connections won’t be water tight. The plastic shroud fits snuggly on the cable, but it doesn’t make a tight connection with the back of the light - which means water could go through the connector into the light. I probably should have noticed this earlier but was too busy following the tutorial video.

I wouldn’t be comfortable leaving the cables so exposed so does anyone have any sealant they’d recommend? This will of course be buried under a shallow layer of soil, and given my choices of kit so far, I thought it best to post on here to ask.

Thanks

 

[pc1966]

Ah, following your link shows you got the indoor glands. This is what you ought to have got:

CW 20mm SWA Gland Pack - 3 Part External - 2 Glands

www.tlc-direct.co.uk

For the indoor garage supply part you can still use them as the armour has to be earthed to the source of power.

However, for the outdoor end you could use IP68 plastic glands for the SWA as you have 3-core so one core would also be the CPC (earth, in addition to the outer armour), and the other cores L & N. Remember to sleeve the conductors to show what they are used for, so green/yellow on the CPC, and blue sleeving on the neutral.

A quick search shows there as probably OK for that cable diameter:

Error 410 | Screwfix

Thousands of products at low trade prices | FREE next day delivery available | 30 day money back guarantee on all orders.

www.screwfix.com

Note most glands do not seal very well except under ideal conditions, so before you put glands on the lights or junction some silicone sealant is a good idea. Unfortunately the sort you typically get for bathrooms, etc, gives off acetic acid as it cures (the vinegar smell) but you can get some that are intended for non-corrosive situations:

RS PRO White Sealant Paste 310 ml Cartridge | RS

uk.rs-online.com

If you can allow the lights to remain open until the normal sealant has cured (typically 24 hours) then it is not a problems. Or if you can ensure that most of the sealant is outside the box (i.e apply a layer between gland and outside before it is screwed in, and wipe away on interior). But having sealed lights with acid fumes inside is going to decrease the expected life a little!