I'm installing exterior lighting in the form of four, ground-level (buried), drive-over type units, within 300mm of the front wall of the building.

All the exterior space (soon will be) shingle. No grass, no flower beds, no earth.

The front of the building is also the car parking space, but you can't realistically drive over the (proposed) position for the lights.

I've already installed an IP66 junction box (MK Masterseal) on the outside wall, close to ground level.

Plan is:
2 of nyy-j cables from junction box to 2 lights (which each have 2 of compression glands on the base), either side of front door.

2 of nyy-j cables from each of these lights, to a 2nd light also either side of front door.

Cables direct buried, bedded in sand, but no additional protection. Warning tape buried above.

Whole area covered in ground-grid type support for pea shingle.

Some sort of capping where the cables come above ground, up the wall to the junction box (maybe 250mm exposed).


Realistically, I don't think I'm going to get the cables 450mm deep - maybe 300mm.

I don't want the hassle of SWA cable.

Adequate?

I guess I could slip the nyy-j inside loose-fitted flexible conduit for additional mechanical protection. Using the existing glands on the lights to clamp up on the nyy-j looks best for waterproofing (with maybe a smear of ls-x).

wrote:
I'm installing exterior lighting in the form of four, ground-level
(buried), drive-over type units, within 300mm of the front wall of
the building.

All the exterior space (soon will be) shingle. No grass, no flower
beds, no earth.

The front of the building is also the car parking space, but you
can't realistically drive over the (proposed) position for the
lights.

I've already installed an IP66 junction box (MK Masterseal) on the
outside wall, close to ground level.

Plan is:
2 of nyy-j cables from junction box to 2 lights (which each have 2 of
compression glands on the base), either side of front door.

2 of nyy-j cables from each of these lights, to a 2nd light also
either side of front door.

Cables direct buried, bedded in sand, but no additional protection.
Warning tape buried above.

Whole area covered in ground-grid type support for pea shingle.

Some sort of capping where the cables come above ground, up the wall
to the junction box (maybe 250mm exposed).


Realistically, I don't think I'm going to get the cables 450mm deep -
maybe 300mm.

I don't want the hassle of SWA cable.

Adequate?

I guess I could slip the nyy-j inside loose-fitted flexible conduit
for additional mechanical protection. Using the existing glands on
the lights to clamp up on the nyy-j looks best for waterproofing
(with maybe a smear of ls-x).

Any chance of a link to the lights you intend to use?



--
Adam

wrote in message
...
I'm installing exterior lighting in the form of four, ground-level
(buried), drive-over type units, within 300mm of the front wall of the
building.

All the exterior space (soon will be) shingle. No grass, no flower beds,
no earth.

The front of the building is also the car parking space, but you can't
realistically drive over the (proposed) position for the lights.

I've already installed an IP66 junction box (MK Masterseal) on the outside
wall, close to ground level.

Plan is:
2 of nyy-j cables from junction box to 2 lights (which each have 2 of
compression glands on the base), either side of front door.

2 of nyy-j cables from each of these lights, to a 2nd light also either
side of front door.

Cables direct buried, bedded in sand, but no additional protection.
Warning tape buried above.

Whole area covered in ground-grid type support for pea shingle.

Some sort of capping where the cables come above ground, up the wall to
the junction box (maybe 250mm exposed).


Realistically, I don't think I'm going to get the cables 450mm deep -
maybe 300mm.

I don't want the hassle of SWA cable.


Why is SWA cable a hassle? No special tools are required.

On 09/08/2013 16:33, wrote:

Adequate?

quote from [1]
[NYY-J] Application range
Power and control cable for fixed installation in the following
applications:
For indoor and outdoor use
Burial without additional, suitable underground protection according to
VDE standard HD 603/VDE 0276-603 - Part 3-G (point 4)
governing PVC cables for direct burial: normal minimum installation
depth 0.6 m, but at least 0.8 m under roads
In concrete with a temperature below the maximum cable operating
temperature of +70 °C according to the VDE standard HD
603/VDE 0276-603 - Part 3-G (point 4) governing PVC cables for direct burial
In water: no longer than 2 weeks at a time, maximum submersion depth 10
metres, only in static water/bodies of water without
shipping traffic
/quote

Since you won't meet the above depths I'd suggest some hard protection:
concrete cable covers or similar.

[2] Might also be of interest - seems you're not the first...

*****

[1] http://products.lappgroup.com/nc/pdf...?pageID=809573

[2]
http://www.theiet.org/forums/forum/m...nterthre ad=y

--
Andy

Any chance of a link to the lights you intend to use?


http://www.toolstation.com/shop/Ligh.../sd2663/p27071

On Friday 09 August 2013 22:06 Andy Wade wrote in uk.d-i-y:

Since you won't meet the above depths I'd suggest some hard protection:
concrete cable covers or similar.

[2] Might also be of interest - seems you're not the first...

*****

[1] http://products.lappgroup.com/nc/pdf...?pageID=809573

[2]

http://www.theiet.org/forums/forum/m...nterthre ad=y


Fundamentally this stuff does not have an earthed screen (which the armour
in SWA acts as). An earthed screen will guarantee that a metal tool that
penetrates the cable will be earthed *before* it hits a live conductor,
tripping the protective device (fuse/MCB/RCD).

My conclusion, irrespective of any claims or regulations, is *I would not
use this cable underground* unless it was inside earthed metal conduit or
similar.

Besides, small SWA is hardly difficult to work with - I don;t see the OP's
problem...

Cheers,

Tim

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

On 10/08/2013 09:36, Tim Watts wrote:

Fundamentally this stuff does not have an earthed screen (which the armour
in SWA acts as). An earthed screen will guarantee that a metal tool that
penetrates the cable will be earthed *before* it hits a live conductor,
tripping the protective device (fuse/MCB/RCD).

My conclusion, irrespective of any claims or regulations, is *I would not
use this cable underground* unless it was inside earthed metal conduit or
similar.

BS 7671 does not impose an absolute requirement for an earthed covering.

Reg. 522.8.10: "Except where installed in a conduit or duct which
provides equivalent protection against mechanical damage, a cable buried
in the ground shall incorporate an earthed armour or metal sheath or
both, suitable for use as a protective conductor. The location of
buried cables shall be marked by cable covers or a suitable marking
tape. Buried conduits and ducts shall be suitably identified. Buried
cables, conduits and ducts shall be at a sufficient depth to avoid being
damaged by any reasonably foreseeable disturbance of the ground."

A concrete channel and cover could be used to form a duct providing
mechanical protection and also marking the location.

Besides, small SWA is hardly difficult to work with - I don;t see the OP's
problem...

That depends a bit on the cable entries provided on the luminaires.

I'm taking it as read that 30 mA RCD protection will be provided for the
feeding circuit.

--
Andy

Andy Wade wrote:
On 10/08/2013 09:36, Tim Watts wrote:

Fundamentally this stuff does not have an earthed screen (which the
armour in SWA acts as). An earthed screen will guarantee that a
metal tool that penetrates the cable will be earthed *before* it
hits a live conductor, tripping the protective device (fuse/MCB/RCD).

My conclusion, irrespective of any claims or regulations, is *I
would not use this cable underground* unless it was inside earthed
metal conduit or similar.

BS 7671 does not impose an absolute requirement for an earthed
covering.
Reg. 522.8.10: "Except where installed in a conduit or duct which
provides equivalent protection against mechanical damage, a cable
buried in the ground shall incorporate an earthed armour or metal
sheath or both, suitable for use as a protective conductor. The
location of buried cables shall be marked by cable covers or a
suitable marking tape. Buried conduits and ducts shall be suitably
identified. Buried cables, conduits and ducts shall be at a
sufficient depth to avoid being damaged by any reasonably foreseeable
disturbance of the ground."
A concrete channel and cover could be used to form a duct providing
mechanical protection and also marking the location.

Besides, small SWA is hardly difficult to work with - I don;t see
the OP's problem...

That depends a bit on the cable entries provided on the luminaires.

I'm taking it as read that 30 mA RCD protection will be provided for
the feeding circuit.

I am wondering if ducting and flex might be a better option.

--
Adam

Besides, small SWA is hardly difficult to work with - I don;t see the OP's

problem...



That depends a bit on the cable entries provided on the luminaires.


Yes the fittings are well suited to NYY-J cable, although no doubt they could be adapted to SWA.


My own opinion is that the relatively short cable runs, max 2.5m from external junction box, and 1.5m light to light - make it pretty obvious there's a buried cable run.


I'm taking it as read that 30 mA RCD protection will be provided for the

feeding circuit.

On it's own RCBO.

On Saturday 10 August 2013 14:12 Andy Wade wrote in uk.d-i-y:

On 10/08/2013 09:36, Tim Watts wrote:

Fundamentally this stuff does not have an earthed screen (which the
armour in SWA acts as). An earthed screen will guarantee that a metal
tool that penetrates the cable will be earthed *before* it hits a live
conductor, tripping the protective device (fuse/MCB/RCD).

My conclusion, irrespective of any claims or regulations, is *I would not
use this cable underground* unless it was inside earthed metal conduit or
similar.

BS 7671 does not impose an absolute requirement for an earthed covering.

Yep - that's why I very carefully made my statement as I did

Essentially, if I stick a fork in that cable, I want the tool to hit mains-
earth before it hits a live conductor.

At times like these, I will happily exceed the regs if I'm unhappy with
their strict application in a particular scenario. You may disagree in this
case.

But I think a residential garden having un-armoured cables buried direct in
the ground is a very very bad idea.

....


A concrete channel and cover could be used to form a duct providing
mechanical protection and also marking the location.

Or that - but we're back to "is SWA really so hard that concrete troughts
would be easier!"

Besides, small SWA is hardly difficult to work with - I don;t see the
OP's problem...

That depends a bit on the cable entries provided on the luminaires.

Well - this is true. if they are anything like internal lumineres! I'd take
the SWA into a Pratley box which is ideal for waterproof maintainable SWA
terminations. Have that as close to the light as possible and make the final
very short connection as suits the fitting. The Pratley box makes a good
junction/loop through JB too if that suits how the cabling is to be laid.

I'm taking it as read that 30 mA RCD protection will be provided for the
feeding circuit.

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

NYY-J is more for surface cable runs (unless very deep as indicated by A.Wade), is expensive £1.20-1.50/metre? for something offering no protection compared to SWA.

You could use a BS8436 cable, the conductor bundle is wrapped in foil which is specifically designed to withstand short circuit fault currents ONLY with suitable Type-B MCB protection (eg, 20A for 2.5mm). It is not a trivial foil screening, it is continuous with an uninsulated tinned copper earth conductor. Glands are plastic as opposed to the unwieldy brass/SWA combination.

On 10/08/2013 21:14, Tim Watts wrote:
[...]
Essentially, if I stick a fork in that cable, I want the tool to hit mains-
earth before it hits a live conductor.

Your fork or spade will almost certainly in contact with the soil when
it penetrates the cable and the loop impedance in the vast majority of
cases will be low enough to trip a 30 mA RCD in milliseconds. I agree
that it's a different matter for a non-RCD-protected circuit but even
then most digging implements have insulated handles.

At times like these, I will happily exceed the regs if I'm unhappy with
their strict application in a particular scenario. You may disagree in this
case.

Fairynuff.

But I think a residential garden having un-armoured cables buried direct in
the ground is a very very bad idea.

Well, to be pedantic, almost every house has a service cable under the
front garden. These cables aren't armoured, but are of concentric or
lead sheathed construction. Time says these aren't a great hazard.

Moreover... how do you connect SWA to equipment underground? Crimped
resin-filled joints would be OK, but are expensive and would require the
equipment to be compatible. Burying SWA glands is surely a no-no, even
'CW' type. The gland makes the connection in the CPC, so has to be
accessible for inspection and testing [543.3.3 and 526.3]. The only
get-outs I can see are 526.3(i) - but SWA glands aren't designed to be
buried - or 526.3(v) - is there a relevant product standard? 543.3.1
also needs to be considered, re. corrosion - specifically the risk of
dezincification of a brass gland in some soils. NYY-J and plastic
glands seem more attractive now...

--
Andy

On Monday 12 August 2013 11:20 Andy Wade wrote in uk.d-i-y:

Hi Andy,

On 10/08/2013 21:14, Tim Watts wrote:
[...]
Essentially, if I stick a fork in that cable, I want the tool to hit
mains- earth before it hits a live conductor.

Your fork or spade will almost certainly in contact with the soil when
it penetrates the cable and the loop impedance in the vast majority of
cases will be low enough to trip a 30 mA RCD in milliseconds. I agree
that it's a different matter for a non-RCD-protected circuit but even
then most digging implements have insulated handles.

Dry earth?

At times like these, I will happily exceed the regs if I'm unhappy with
their strict application in a particular scenario. You may disagree in
this case.

Fairynuff.

But I think a residential garden having un-armoured cables buried direct
in the ground is a very very bad idea.

Well, to be pedantic, almost every house has a service cable under the
front garden. These cables aren't armoured, but are of concentric or
lead sheathed construction. Time says these aren't a great hazard.

Yes - and the concentric nature means the tool will hit either earth or the
neutral in a PME system first. Though I do agree a service cable fused at
300A will go bang quite nicely.

Moreover... how do you connect SWA to equipment underground? Crimped
resin-filled joints would be OK, but are expensive and would require the
equipment to be compatible. Burying SWA glands is surely a no-no, even
'CW' type. The gland makes the connection in the CPC, so has to be
accessible for inspection and testing [543.3.3 and 526.3]. The only
get-outs I can see are 526.3(i) - but SWA glands aren't designed to be
buried - or 526.3(v) - is there a relevant product standard? 543.3.1
also needs to be considered, re. corrosion - specifically the risk of
dezincification of a brass gland in some soils. NYY-J and plastic
glands seem more attractive now...


http://www.tlc-direct.co.uk/Products/PRUBX02.html

Pratley boxes claim to be suitable for underground SWA jointing without gel
or resin filling. Do the manufacturer claims trump the regs?


Cheers,

Tim

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

On Monday, August 12, 2013 11:20:01 AM UTC+1, Andy Wade wrote:
On 10/08/2013 21:14, Tim Watts wrote:

snip
But I think a residential garden having un-armoured cables buried direct in
the ground is a very very bad idea.



Well, to be pedantic, almost every house has a service cable under the
front garden. These cables aren't armoured, but are of concentric or
lead sheathed construction. Time says these aren't a great hazard.

Really?
I'm not in a position to check it now, but I'm pretty sure that the service cable in my first house was like the one in the present one, which is lead sheathed (presumably PILC) with a steel tape armour.
(my second house had overhead cables, even though it was in a small town rather than rural location, and there are still quite a number of others with overhead mains connections)

On Monday 12 August 2013 13:48 wrote in uk.d-i-y:

On Monday, August 12, 2013 11:20:01 AM UTC+1, Andy Wade wrote:
On 10/08/2013 21:14, Tim Watts wrote:

snip
But I think a residential garden having un-armoured cables buried
direct in the ground is a very very bad idea.



Well, to be pedantic, almost every house has a service cable under the
front garden. These cables aren't armoured, but are of concentric or
lead sheathed construction. Time says these aren't a great hazard.

Really?
I'm not in a position to check it now, but I'm pretty sure that the
service cable in my first house was like the one in the present one, which
is lead sheathed (presumably PILC) with a steel tape armour. (my second
house had overhead cables, even though it was in a small town rather than
rural location, and there are still quite a number of others with overhead
mains connections)

I've seen he end of mine, in the cutout. Outer insulated neutral strands
(PME) and inner live core.

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

NYY-J and plastic glands seem more attractive now...

This pretty much hits the nail on the head. The inset light fittings sit 270mm deep into the ground and have a pair of plastic compression glands in the base. These glands *could* be replaced with SWA glands, but the glands need to screw directly into the cast plastic body (so the interior locknut and earth tab can't be used).

As opinion here was pretty firmly in favour of SWA, I'd given some thought to how to do it that way - but it's still coming back to the light fittings being most suited to NYY-J.

On 12/08/2013 13:48, wrote:
Really?
I'm not in a position to check it now, but I'm pretty sure that the
service cable in my first house was like the one in the present one,
which is lead sheathed (presumably PILC) with a steel tape armour.
(my second house had overhead cables, even though it was in a small
town rather than rural location, and there are still quite a number
of others with overhead mains connections)

Here's an interesting document about power cables, suggesting that
you're right about the PILC cables being armoured.

http://www.spenergynetworks.co.uk/sa...20theft%29.pdf

--
Andy

wrote:
NYY-J and plastic glands seem more attractive now...

This pretty much hits the nail on the head. The inset light fittings
sit 270mm deep into the ground and have a pair of plastic compression
glands in the base. These glands *could* be replaced with SWA glands,
but the glands need to screw directly into the cast plastic body (so
the interior locknut and earth tab can't be used).

As opinion here was pretty firmly in favour of SWA, I'd given some
thought to how to do it that way - but it's still coming back to the
light fittings being most suited to NYY-J.

One of the reasons I asked for a link to the lights you wanted to fit was
because I wanted to know how I could connect them to a cable. And the truth
is, I am still not sure how I would wire them up:-). I would not be happy
with either SWA or nylon compression glands buried underground.

I have one other suggestion for you. Use LED lights with a built in cable
(they will be epoxy resin IP protected) and then you pass this cable through
some ducting to a LED driver. It would make replacement easier should it be
needed.

Now as most people know, I am not a snob. But I have to be totally honest
and I believe that a £20 lightfitting is not really going to cut the mustard
in this case. The lights you linked to are PKE Pro Spec lights - and I have
never heard of them. They might be suitable for use on decking but I would
not fit them on a driveway or indeed in a footpath due to the difficulties
of keeping them watertight in what is in real terms a submerged position.

I'll still help you whatever you decide to do/buy.


--
Adam

On Monday, 12 August 2013 18:59:42 UTC+1, wrote:
wrote:

NYY-J and plastic glands seem more attractive now...



This pretty much hits the nail on the head. The inset light fittings

sit 270mm deep into the ground and have a pair of plastic compression

glands in the base. These glands *could* be replaced with SWA glands,

but the glands need to screw directly into the cast plastic body (so

the interior locknut and earth tab can't be used).



As opinion here was pretty firmly in favour of SWA, I'd given some

thought to how to do it that way - but it's still coming back to the

light fittings being most suited to NYY-J.



One of the reasons I asked for a link to the lights you wanted to fit was

because I wanted to know how I could connect them to a cable. And the truth

is, I am still not sure how I would wire them up:-). I would not be happy

with either SWA or nylon compression glands buried underground.



I have one other suggestion for you. Use LED lights with a built in cable

(they will be epoxy resin IP protected) and then you pass this cable through

some ducting to a LED driver. It would make replacement easier should it be

needed.



Now as most people know, I am not a snob. But I have to be totally honest

and I believe that a £20 lightfitting is not really going to cut the mustard

in this case. The lights you linked to are PKE Pro Spec lights - and I have

never heard of them. They might be suitable for use on decking but I would

not fit them on a driveway or indeed in a footpath due to the difficulties

of keeping them watertight in what is in real terms a submerged position.



I'll still help you whatever you decide to do/buy.





--

Adam

I agree they are a pretty cheap fitting. But I bought one to check the quality and was pleasantly surprised. Price jump to next rung in quality seemed to be about £75 (which I'd swallow for 1, but not 4). I'm using PAR30 LED lamps with them (having checked the brightness/colour/beam dispersion). Purpose is to illuminate the front of an (old) building (in a dark rural area).

About the fitting - body good, polycarb lens/cover good (incl 2 rubber gaskets), glands good, lampholder not so good (Ikea sort of quality).

I'm thinking a smear of LS-X silicon on the glands and lens to keep the fitting as watertight as possible.

Moreover... how do you connect SWA to equipment underground?

A compromise occurred to me - use SWA, but take it into the light fittings by the existing compression glands (rated IP68), rather than CW SWA glands (IP66).

Use 3-core SWA, and WAGO's inside the light fittings for continuity on the earth core (L & N continuity via the lamp holder).

(the light fittings really need to be daisy-chained)

But without an SWA gland, how can the steel wire screen be clamped to?

Alternatives seem to be:
1. Run 4 individual cables from the above-ground junction box, CW SWA glands at that end, compression gland at the underground light fitting (so screen clamped one end only).
2. Use the smaller BW SWA glands inside each light fittings to clamp the screen (though these wouldn't be fixed to anything).
3. Find some other way of clamping to the screen.
4. Leave the screen floating.

On Tuesday, August 13, 2013 10:18:23 AM UTC+1, wrote:
A compromise occurred to me - use SWA, but take it
into the light fittings by the existing compression
glands (rated IP68), rather than CW SWA glands (IP66).
....
4. Leave the screen floating.

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 relevant type-b mcb, cable has small diameter, easily bent, uses standard glands).
- For high end light fittings, scour Ebay & Online for end of line JCC fittings.

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

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


Moreover... how do you connect SWA to equipment underground?

A compromise occurred to me - use SWA, but take it into the light fittings
by the existing compression glands (rated IP68), rather than CW SWA glands
(IP66).

Use 3-core SWA, and WAGO's inside the light fittings for continuity on the
earth core (L & N continuity via the lamp holder).

(the light fittings really need to be daisy-chained)

But without an SWA gland, how can the steel wire screen be clamped to?

Alternatives seem to be:
1. Run 4 individual cables from the above-ground junction box, CW SWA
glands at that end, compression gland at the underground light fitting (so
screen clamped one end only). 2. Use the smaller BW SWA glands inside each
light fittings to clamp the screen (though these wouldn't be fixed to
anything).


3. Find some other way of clamping to the screen. 4. Leave the
screen floating.

No and no.

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

'fraid none of your earlier postings have appeared here.

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

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

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

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

No and no.


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.

wrote:
On Tuesday, August 13, 2013 10:18:23 AM UTC+1, wrote:
A compromise occurred to me - use SWA, but take it
into the light fittings by the existing compression
glands (rated IP68), rather than CW SWA glands (IP66).
...
4. Leave the screen floating.

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 relevant type-b mcb, cable has small diameter, easily bent,
uses standard glands).

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

--
Adam

wrote:
'fraid none of your earlier postings have appeared here.

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

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

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

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

Well JCC are not known for making qualitly lights.

--
Adam

wrote:
On Monday, 12 August 2013 18:59:42 UTC+1,
wrote:
wrote:

NYY-J and plastic glands seem more attractive now...



This pretty much hits the nail on the head. The inset light fittings

sit 270mm deep into the ground and have a pair of plastic
compression

glands in the base. These glands *could* be replaced with SWA
glands,

but the glands need to screw directly into the cast plastic body (so

the interior locknut and earth tab can't be used).



As opinion here was pretty firmly in favour of SWA, I'd given some

thought to how to do it that way - but it's still coming back to the

light fittings being most suited to NYY-J.



One of the reasons I asked for a link to the lights you wanted to
fit was

because I wanted to know how I could connect them to a cable. And
the truth

is, I am still not sure how I would wire them up:-). I would not be
happy

with either SWA or nylon compression glands buried underground.



I have one other suggestion for you. Use LED lights with a built in
cable

(they will be epoxy resin IP protected) and then you pass this cable
through

some ducting to a LED driver. It would make replacement easier
should it be

needed.



Now as most people know, I am not a snob. But I have to be totally
honest

and I believe that a £20 lightfitting is not really going to cut the
mustard

in this case. The lights you linked to are PKE Pro Spec lights - and
I have

never heard of them. They might be suitable for use on decking but I
would

not fit them on a driveway or indeed in a footpath due to the
difficulties

of keeping them watertight in what is in real terms a submerged
position.



I'll still help you whatever you decide to do/buy.





--

Adam

I agree they are a pretty cheap fitting. But I bought one to check
the quality and was pleasantly surprised. Price jump to next rung in
quality seemed to be about £75 (which I'd swallow for 1, but not 4).
I'm using PAR30 LED lamps with them (having checked the
brightness/colour/beam dispersion). Purpose is to illuminate the
front of an (old) building (in a dark rural area).

About the fitting - body good, polycarb lens/cover good (incl 2
rubber gaskets), glands good, lampholder not so good (Ikea sort of
quality).

I'm thinking a smear of LS-X silicon on the glands and lens to keep
the fitting as watertight as possible.

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.

--
Adam

On Monday, August 12, 2013 6:28:52 PM UTC+1, Andy Wade wrote:
On 12/08/2013 13:48, wrote:

I'm not in a position to check it now, but I'm pretty sure that the
service cable in my first house was like the one in the present one,
which is lead sheathed (presumably PILC) with a steel tape armour.
(my second house had overhead cables, even though it was in a small
town rather than rural location, and there are still quite a number
of others with overhead mains connections)

Here's an interesting document about power cables, suggesting that
you're right about the PILC cables being armoured.

http://www.spenergynetworks.co.uk/sa...20theft%29.pdf

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.

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

drive over the lights?

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 something 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 across the frontage. When I tested with 1 light, it seemed to produce the desired wall-washing effect.

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


I think I'm coming round to the idea of a single daisy-chain of all 4 lights 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 glands on a small metal plate (say 80 * 40mm).

On Tuesday, August 13, 2013 6:11:29 PM UTC+1, wrote:
Well JCC are not known for making qualitly lights.

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".

On Tuesday, August 13, 2013 3:09:48 PM UTC+1, wrote:
Is BS8436 suitable for direct burial in soil,

With flexible conduit protection.
It is a novel cable, a little stiff as solid core, but nothing like the sheath 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.

or for above-ground applications buried in plaster?

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

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

On Tuesday, August 13, 2013 3:09:48 PM UTC+1, wrote:
Is BS8436 suitable for direct burial in soil,

With flexible conduit protection.
It is a novel cable, a little stiff as solid core, but nothing like the sheath 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.

or for above-ground applications buried in plaster?

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

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

On 13/08/2013 20:31, wrote:

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

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.

--
Andy

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:

http://www.toolstation.com/shop/Drap...Cutter+/p29436

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

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:

http://www.toolstation.com/shop/Drap...Cutter+/p29436

Sounds like a class job - any pictures?

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

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

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

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

robgraham wrote:
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.

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

--
Adam

wrote:
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:

http://www.toolstation.com/shop/Drap...Cutter+/p29436

Congratulations sir.

--
Adam

On Sunday, 18 August 2013 18:30:44 UTC+1, wrote:
robgraham wrote:

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.



The complications of the SWA in the OPs case was terminating it underground

at the light fitting.



--

Adam

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