Extending existing swa garden light circuit and adding fittings

[Johnny-G]

A customer has 2 lights on a 30m circuit in 1.5mm swa which is buried half way round the perimeter of the garden and the lights are spurred off it at the end via Y boxes, they want another 10 lights added.
I would normally use Wiska boxes & earth clamps but they want it as discrete as possible so I'm looking at black enamel conduit boxes which I've never used in this situation before.
How much space is in these things, ie is there enough inside to terminate 4x 1.5mm 3 cores in a 4 way box? Do standard plastic glands fit in the ends like swa glands appear to? & how do you earth the sheath at the end?

 

[Engineer54]

Your having a laugh!!, .....Right?? Black conduit boxes, ...Buried???

 

[Deleted member 26818]

Will you be using a rubber gasket?

 

[Johnny-G]

Your having a laugh!!, .....Right?? Black conduit boxes, ...Buried???

Not buried no and I'm talking about the metal type not the crappy plastic ones.

Will you be using a rubber gasket?

Of course.

 

[Deleted member 26818]

You'll be hard pressed to terminate 4 3core cables in one 25mm box. Might be able to crimp some or all of them?

 

[High Tower]

The only way to do this is.....

1, join cables in a resin filled underground torpedo and bury, test IR and contanuity before pouring resin!!

2, terminate with CW glands into a IP rated adaptable box and fix ABOVE ground

 

[Engineer54]

Not buried no and I'm talking about the metal type not the crappy plastic ones.QUOTE]

I was talking about black metal conduit boxes!! PVC conduit boxes are not threaded, not the ones i know of anyway.... And you did state that the SWA cable was buried!!!

For Exterior conduit, you never use the Black stuff, but Galvanised. Personally i would not be using conduit boxes of any type for garden work but purpose made IP rated boxes/enclosures.

 

[BlueToBits]

Steel conduit boxes, even with a gasket, are not as waterproof as you would think. They really need to be sheltered from rain. It is possible to fit four 5A connectors, but the box needs to be earthed, and you have to be really neat with your wiring. PVC stuffing glands will fit but ensure they all have gasket washers.
You are firmly in part P country here so consider the implications in undertaking this. Also consider galv rather than enamel.

 

[BlueToBits]

Wow! a triple bypass post!

 

[nickblake]

Black galv conduit boxes push fit wago's completely wire test then fill each box up with resin to water proof or use a 3 way under ground joint and bury

 

[Johnny-G]

You'll be hard pressed to terminate 4 3core cables in one 25mm box. Might be able to crimp some or all of them?

I was looking at 20mm boxes (that's what's in use at the mo) so I guess they're out of the question if 25mm would be cramped

The only way to do this is.....

1, join cables in a resin filled underground torpedo and bury, test IR and contanuity before pouring resin!!

2, terminate with CW glands into a IP rated adaptable box and fix ABOVE ground

Whilst that's the correct way, in this case it might be overkill as the existing terminals are above ground and accessible.

Not buried no and I'm talking about the metal type not the crappy plastic ones.QUOTE]

I was talking about black metal conduit boxes!! PVC conduit boxes are not threaded, not the ones i know of anyway.... And you did state that the SWA cable was buried!!!

For Exterior conduit, you never use the Black stuff, but Galvanised. Personally i would not be using conduit boxes of any type for garden work but purpose made IP rated boxes/enclosures.

The cable ends are easy enough to tap in to and I'll probably use a Wiska box there, it was just how to run all the lights off it without using another 5/6 of them.

 

[pennywise]

or prately boxes with magic gel.



They come with SWA glands that are integral so you save on the cost of gland packs if your worried about the boxes high price.

 

[Johnny-G]

or prately boxes with magic gel.

View attachment 5671

They come with SWA glands that are integral so you save on the cost of gland packs if you worried about the boxes high price.

Even using a 3 way size 0 I'd need 10 minimum which really bumps the price up.

 

[pennywise]

Could you not get away with 4 ways and have two lights per box.

 

[Johnny-G]

Possibly, the lights I'm installing come with 2m flex per fitting so I may have to do a bit more measuring to see if it's feasible

 

[Octopus]

Even using a 3 way size 0 I'd need 10 minimum which really bumps the price up.

Yes the price may go up but you, as the designer, will be responsible for the installation and signing it off.

If the price goes up simply make sure that the client understands the cost of providing such joints and why, in the long term, the reliability will pay off.

 

[High Tower]

Use one of these with CW glands, and if you really feel the need fill it with resin! job done and a fraction of the price

 

[mogga]

4x4 plastic box ce glands earthnuts inside box seal with raychem blue gell bury box cable marking tape sorted