nyy-j cable - direct burial?

[js.b1]

...

I suspect my posts are not being read or getting out, but...

- YUCK!!

- BS8436 solves your problem here (CPC foil is rated to SC fault tripping r elevant type-b mcb, cable has small diameter, easily bent, uses standard gl ands).

- For high end light fittings, scour Ebay & Online for end of line JCC fitt ings.

JCC branded Augenti etc are often commercial grade, typically £60-150 eac h yet can be had for about £20-55 as they offload them. Go thro the JCC w ebsite, pick what you like and hunt for heavy discounts.

[Tim Watts]

On Tuesday 13 August 2013 10:18 [e-mail] wrote in uk.d-i-y:

No and no.

[dom]

'fraid none of your earlier postings have appeared here.

Is BS8436 suitable for direct burial in soil, or for above-ground applications buried in plaster?

Had a look at the JCC website. Unfortunately they don't have anything matching my needs, but thanks anyway.

[dom]

Agreed. Added to the list for completeness, or in case there was a specific SWA screen clamping product I was unaware of.

If SWA is used, it would seem the only practical option would be to make up a small metal plate to hold two SWA glands side-by-side within the light fitting.

[ARW]

That is certainly a viable option. It would have to be in conduit when buried.

[ARW]

Well JCC are not known for making qualitly lights.

[ARW]

So just the cable to sort out then:-)

Will cars drive over the buried cable? You have said that they will not drive over the lights?

And js.b1s suggestion of BS8436 cable should not be ignored.

[docholliday93]

The picture on P 20 looks just like what I have - even to the bit of steel tape being exposed where the contractor fiddled about with the earthing after replacing the meter... I can't see anything of the construction inside the lead sheath, of course, since that vanishes inside a cast iron receptacle filled (I assume) with pitch. The document suggests they stopped using this construction in the mid '70s, but since the house is Victorian I'm sure this has been there a good deal longer than that.

[dom]

Apologies that I keep having to add extra detail. As always it's a balance between a story too long and full of irrelevant details, and missing someth ing out.

It's an old building, with an area roughly 2m deep and 12m wide across the front of the building, with a dropped kerb across the whole frontage. Area was tatty tarmac, will be shingle shortly.

The only practical place to put lighting is within about 300mm of the front of the building, and the layout will be 4 roughly equally spaced lights ac ross the frontage. When I tested with 1 light, it seemed to produce the des ired wall-washing effect.

I think it's unlikely anyone will ever be able to drive over a light or a c able when parking.

I think I'm coming round to the idea of a single daisy-chain of all 4 light s with SWA. From wall-mounted junction box and CW SWA gland, then in/out of each light. Lights retain their plastic glands, but internally fit 2 SWA g lands on a small metal plate (say 80 * 40mm).

[js.b1]

They are not that bad... then again I have only used Augenti which are reasonable die cast units. They are Italian... which often seems to result in "aesthetic design is good, engineering came later and not quite".

[js.b1]

With flexible conduit protection. It is a novel cable, a little stiff as solid core, but nothing like the she ath on NYY-J which would drive you nuts with most light fittings. Few light fitting designers have actually tried installing them! Mr W will probably attest to that, installing crap lights is a bit like a visit to the dentist over & over.

Certainly, that was the point re not requiring RCD protection.

Give Prysmian a phone and ask for technical (previously called Pirelli), th ey do have engineers there rather than the marketing drips you so often enc ounter these days.

[js.b1]

With flexible conduit protection. It is a novel cable, a little stiff as solid core, but nothing like the she ath on NYY-J which would drive you nuts with most light fittings. Few light fitting designers have actually tried installing them! Mr W will probably attest to that, installing crap lights is a bit like a visit to the dentist over & over.

Certainly, that was the point re not requiring RCD protection.

Give Prysmian a phone and ask for technical (previously called Pirelli), th ey do have engineers there rather than the marketing drips you so often enc ounter these days.

[Andy Wade]

I'm fairly sure they'll tell you that BS 8436 cable is not suitable for use underground. Check out Annex A.1 to the standard.

[dom]

OK - job done.

Many thanks to all that took an interest.

Actual solution used was 3-core SWA cable, daisy chain all the lights in one single line from the junction box (although physical layout is 2 each side).

I retained the existing compression glands on base of the buried light fittings, but made up 40*80mm steel plates with 20mm holes punched to go inside each fittings to carry a pair of BW (indoor) SWA glands side by side.

Overall this was rock-solid, IP68 compression glands to seal the light fittings, internal SWA glands to terminate the armour. 8 SWA glands were a bit of work. Incidentally, I bought Draper Expert hard-wire cutters from ToolStation - I recommend these:

[Tim Watts]

On Sunday 18 August 2013 14:52 [e-mail] wrote in uk.d-i-y:

Sounds like a class job - any pictures?

[robgraham]

On Tuesday, August 13, 2013 6:10:34 PM UTC+1,

I'm going to take advantage of this post which I found useful as I'm close enough now to putting up a polytunnel to consider how I'm going to get power to it. The distance will be in the order of 10m from the house.

From the discussion here it's going to be SWA, or this NYY-J (which I hadn't heard of before) in a duct.

What are the complications of SWA and how do I install it. I'm in Scotland so don't suffer Part P and do have technical competency.

Rob

[dom]

First advice - dig your trench - that may influence your choice (I hit conc rete, and had to compromise on cable depth in that area).

Second advice - get hold of some SWA and practice putting on the glands bef ore you do the real install. I've got donkey's years professional experienc e in wiring awkward electronics connectors, but still needed a couple of pr actices with SWA glands to get a nice neat result.

[ARW]

The complications of the SWA in the OPs case was terminating it underground at the light fitting.

[ARW]

Congratulations sir.

[dom]

I managed to do all the assembly work indoors, apart from the final SWA gla nd into the junction box (which needed to be cut-to-fit in situ)- but, as y ou say, the head scratching bit was the combination of compression glands a nd SWA glands for the underground part.