External lighting

[Paul Chick]

Hi guys,

Ive got a few outside lights to wire in next weekend and was wondering what sort of flex would be durable enough to go from the galv 'T' box upto the lights?
Im looping the lights round in armoured flex through 'T' boxes because i obviously cant make of those connections within the light fittings themselves due to space and looking crap.

Cheers,

Paul

 

[stuart569]

3183Y will be fine

 

[Paul Chick]

ideal, cheers

 

[SimpleSimon]

Before you do this, can i ask why galvanised boxes? I ask because ive just finished an ongoing job where posh flats had LED outside lights installed in the planters. After the first two years these lights started to trip. On coming into this we discovered all lights had been looped in using swa into 't' boxes galvanised, exactly how you plan. All connections where fine but the majority of boxes where flooded with water and had rusted away under the soil due to the lack of IP rating and sealant. We went in and changed the lights and all the junctiin boxes to IP rated boxes and wacked a load of sealant around all connections.

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[Paul Chick]

Obviously not installed correctly mate. If you terminate the cables right and use a good gasket you shouldn't have any issues. Plus the boxes are being fixed to a secure surface and not left lying around.

Cheers,

Paul

 

[Engineer54]

Hi guys,

Ive got a few outside lights to wire in next weekend and was wondering what sort of flex would be durable enough to go from the galv 'T' box upto the lights?
Im looping the lights round in armoured flex through 'T' boxes because i obviously cant make of those connections within the light fittings themselves due to space and looking crap.


Really!!, ....And what sort of depth are you burying these so-called armoured flexible cables??

Cheers,

Paul

Really!!, ....And what sort of depth are you burying these so-called armoured flexible cables??
For a start, as you have already been informed, Galv conduit boxes are not designed to be buried, they have no IP rating. In fact you shouldn't be burying any boxes that have not been designed to be buried.

So you think making connections off correctly and a bit of sealant and job's a good-un?? Wrong!! ....You've never heard about condensation then. A box sealed tight, will almost certainly produce condensation, you really need to fill the box and connections with a propriety box filling compound, to be sure of continued electrical soundness against corrosion and damp etc.

 

[Paul Chick]

im not burying the cables, where did i say that?

 

[ackbarthestar]

IMO, use IP rated adaptable boxes, the small Wiska boxes will do the job, then SWA cable between the boxes and H07 flexibles with stuffing glands out to the fitting. It usually works for me. Should give at least a 5 year maintenance free life.

 

[i=p/u]

if was in the ground then you add tub of hair gel

 

[SimpleSimon]

Obviously not installed correctly mate. If you terminate the cables right and use a good gasket you shouldn't have any issues. Plus the boxes are being fixed to a secure surface and not left lying around.

Cheers,

Paul

All had gaskets mate but they dont have an IP rating therefore not suitable for the purpose.
54 has the right idea. But my company wouldnt pay the cost for a compound filler. So just IP boxes,
And a load of sealant. Wont last long!
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[GLENNSPARK]

All had gaskets mate but they dont have an IP rating therefore not suitable for the purpose.
54 has the right idea. But my company wouldnt pay the cost for a compound filler. So just IP boxes,
And a load of sealant. Wont last long!
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well thats tight if em innit....how much is it?.....about £4 a stick?.......

 

[ackbarthestar]

All had gaskets mate but they dont have an IP rating therefore not suitable for the purpose.
54 has the right idea. But my company wouldnt pay the cost for a compound filler. So just IP boxes,
And a load of sealant. Wont last long!
Sent from my GT-I9100 using Tapatalk

If the boxes are not going to be buried then filling them with 'gunk' is an extra unnecessary cost.

You don't need a 'jelly' compound even when they are buried, just a good IP rated terminal box with some petroleum jelly around the SWA glands and some WD40 on the terminal blocks.

Adaptable boxes filled with jelly do fail and because they are non-maintainable have to be be ripped out. Better not to bury them at all.

 

[SimpleSimon]

True. But they had no choice but to bury them in stand alone planters. Horrible job because i had to physically climb into the planters to do some fiddly swa glands.

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[GLENNSPARK]

True. But they had no choice but to bury them in stand alone planters. Horrible job because i had to physically climb into the planters to do some fiddly swa glands.

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yeah well that aint as bad as this rented we went to up in harehills (leeds) the other day.....we literally had to "climb" into the living room at that place.....chuffin loads of 1s and 2s there n all....so we will have to go back once we get the goahead from the landlord.......but the way some of em live....its like a different world.....

 

[trev]

You tried social housing yet Glenn? Some of the stuff I've seen there still makes me shudder now

 

[ackbarthestar]

True. But they had no choice but to bury them in stand alone planters. Horrible job because i had to physically climb into the planters to do some fiddly swa glands.

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One job about 18 months ago, I installed 6 of them in raised vegetable beds feeding LED IP rated ground lights, which were mounted into the sides. The client demanded that they were buried. I explained that when buried they disappear and then become susceptible to being damaged by a fork or spade. He called back about a month ago to be told "we hit one of the boxes with a spade, but we put a plastic bag over it" ! ........ 2 weeks later, I went round to have a look and found that the box had been split but no other damage to the glands and cable so was able to change the box within the hour.

 

[GLENNSPARK]

You tried social housing yet Glenn? Some of the stuff I've seen there still makes me shudder now

Not yet Trev but My boss does most of the work for this letting agents up there and most of the landlords in that area seem to use this agents......we get quite a bit of work out of it ...which is always good ....but the amount of these "tennants" that just dont give a FxxK.......the places are always filthy and the tennants often are as well.....a lot of evidence of power pinching n all at a lot of these places....we went in one place and i aint joking when i say there must have been about 30 odd dirty plates and loads of dirty cups n stuff.....the cooker would have set alight if you had turned it on...the amount of grease n fat on it....dog ends everywhare and piles and piles of filthy clothes all over....now i really resent having to wade through all this ---- when on a periodic and that cooker.....we were supposed to pull that thing out as there was a damaged ccu behind it.....well i wasn`t touching that thing....got the tennant to do it......makes me feel ikky sometimes after going in places like that....euggh......

 

[Engineer54]

im not burying the cables, where did i say that?

Sorry, must have assumed to were burying after reading simple simons post ...lol!!!

 

[GLENNSPARK]

Sorry, must have assumed to were burying after reading simple simons post ...lol!!!

would it still not be better to use plastic IP boxes though rather than the galv adaptable ones?.........

 

[Engineer54]

If the boxes are not going to be buried then filling them with 'gunk' is an extra unnecessary cost.

You don't need a 'jelly' compound even when they are buried, just a good IP rated terminal box with some petroleum jelly around the SWA glands and some WD40 on the terminal blocks.

Adaptable boxes filled with jelly do fail and because they are non-maintainable have to be be ripped out. Better not to bury them at all.

I'm sorry, but if you are burying a joint box they will need a filling compound if they are to have any chance of longevity!! Totally sealing any box IP rated or not, and you will induce condensation, and it won't take condensation long to start degrading connections, or metallic boxes. If you look at any IP rated enclosure you will Always find condensation seepage release locations, for drilling 4mm holes...

Bury any box and it needs a filling with a made for purpose compound so that condensation doesn't occur, end of!! We have installed literary hundreds of wisker boxed with the appropriate compound fill, and i've never yet known one to fail, ...not one!!! Ours are normally used on public pedestrian area lighting distribution systems, with interlinked block brick finish, that would cost a fortune to remove and replace, just to get to one of these boxes.

 

[GLENNSPARK]

I'm sorry, but if you are burying a joint box they will need a filling compound if they are to have any chance of longevity!! Totally sealing any box IP rated or not, and you will induce condensation, and it won't take condensation long to start degrading connections, or metallic boxes. If you look at any IP rated enclosure you will Always find condensation seepage release location for drilling 4mm holes...

Bury any box and it needs a filling with a made for purpose compound so that condensation doesn't occur, end of!! We have installed literary hundreds of wisker boxed with the appropriate compound fill, and i've never yet known one to fail, ...not one!!! Ours are normally used on public pedestrian area lighting distribution systems, with interlinked block brick finish, that would cost a fortune to remove and replace, just to get to one of these boxes.

we put some drive lights in the other week at this place and we used an IP box together with a compound filling as it was to be buried....my boss said it was the right thing to do here.......

 

[Engineer54]

would it still not be better to use plastic IP boxes though rather than the galv adaptable ones?.........

Sure it would, good quality one's. Conduit boxes even with gaskets fitted, are not exactly waterproof with just 2 fixing points for the lid, and the lid would need to be the galv cast type lid, not the thin galv sheet steel one's. Galv adaptable boxes fair a little better with gaskets fitted, but as far as i know would still at best only give an IP rating of around IP44...

 

[GLENNSPARK]

Sure it would, good quality one's. Conduit boxes even with gaskets fitted, are not exactly waterproof with just 2 fixing points for the lid, and the lid would need to be the galv cast type lid, not the thin galv sheet steel one's. Galv adaptable boxes fair a little better with gaskets fitted, but as far as i know would still at best only give an IP rating of around IP44...

yes and the thing is eng is i used to work in fabrications so i would look at the rigidity of something like this and its ability to withstand harsh environments .....such as being underground

 

[Engineer54]

yes and the thing is eng is i used to work in fabrications so i would look at the rigidity of something like this and its ability to withstand harsh environments .....such as being underground

I'd only use underground if protected, or assured of non-disturbance, never in a garden area where the ground is prone to digging activities etc...

 

[GLENNSPARK]

I'd only use underground if protected, or assured of non-disturbance, never in a garden area where the ground is prone to digging activities etc...

Yes. along comes "Mr fothargill" and his seeds.....busy with the fork n spade...lol.........

 

[ackbarthestar]

I'm sorry, but if you are burying a joint box they will need a filling compound if they are to have any chance of longevity!! Totally sealing any box IP rated or not, and you will induce condensation, and it won't take condensation long to start degrading connections, or metallic boxes. If you look at any IP rated enclosure you will Always find condensation seepage release locations, for drilling 4mm holes...

Bury any box and it needs a filling with a made for purpose compound so that condensation doesn't occur, end of!! We have installed literary hundreds of wisker boxed with the appropriate compound fill, and i've never yet known one to fail, ...not one!!! Ours are normally used on public pedestrian area lighting distribution systems, with interlinked block brick finish, that would cost a fortune to remove and replace, just to get to one of these boxes.

Interesting,
I've spent the last two years on one particular job digging up so called non-maintainable Gwiss boxes filled with 'jelly' .



All the terminations had corroded and failed. I found that water penetration had managed to penetrate between the compound and the insulation around the conductors.


The only maintainable joint is one that is not buried.



This one had a failed transformer.

I think the longest period of time some of these adaptable boxes had been in the ground was 4 years.

I always maintain that there is no such thing as a non-maintainable underground joint, unless its filled with resin and then you're f****d if it fails

 

[GLENNSPARK]

so what you say here then is a "scotchcast" type joint?.......

 

[Engineer54]

Interesting,
I've spent the last two years on one particular job digging up so called non-maintainable Gwiss boxes filled with 'jelly' .
View attachment 8733


All the terminations had corroded and failed. I found that water penetration had managed to penetrate between the compound and the insulation around the conductors.


The only maintainable joint is one that is not buried.

View attachment 8732

This one had a failed transformer.

I think the longest period of time some of these adaptable boxes had been in the ground was 4 years.

I always maintain that there is no such thing as a non-maintainable underground joint, unless its filled with resin and then you're f****d if it fails

To be honest, i've never used Gewiss boxes, underground or anywhere else, i just don't like them!!
None of those boxes look like they have had the glands terminated very well at all and they look like standard glands not IP 68 rated!! God knows what that filling compound is, nothing like what i've ever seen or used... What ever it is, it doesn't look, as if it's filled the boxes very well at all.

Looks to me like a p**s poor shambolic installation, and not one i'd be happy with. I can well imagine moisture getting to those connections etc!! But as i stated, use the right made for purpose boxes, the right connections (we crimp & shrink in all of ours) a good filling compound, and you should achieve a joint that is going to last for many years to come.

Oh, and we also use resin and heatshrink joints too for our road lighting distribution systems. Mainly for short Tee offs, across paths or whatever. Main lines to the Lamp Posts are ducted to ground pits at the side or in close proximity to the lamppost, (Sometimes joints are also located in these pits) that then enter the lamp post via small duct/conduit...

 

[ackbarthestar]

so what you say here then is a "scotchcast" type joint?.......

Resin filled joints are about the only type that appear to last. They go rock hard.

 

[Engineer54]

Resin filled joints are about the only type that appear to last. They go rock hard.

Nothing wrong with Resin jointing, just a bit OTT for use in a domestic garden to feed garden lights and the like!! lol!!

 

[ackbarthestar]

Nothing wrong with Resin jointing, just a bit OTT for use in a domestic garden to feed garden lights and the like!! lol!!

No, I'd agree, not the average gardens, but when you are dealing with several acres at a time then you require something more permanent.
We use them all the time for repairing and extending sub-mains in SWA. Usually where somebody has dug one up with a digger and it needs a torpedo splice. I haven't had one fail as yet.

Certainly wouldn't use them for any form of flexible.

 

[Paul Chick]

Adaptable boxes look cheap and nasty. So where do Galv boxes stand on the numerous commercial buildings and industrial units our company has done to feed cables in galv conduit or SWA to outside lighting? Its crap, you're going to get condensation build up with what ever you install so it doesn't really matter. But i can safely say that if you make off all your glands correctly/tight and you a half decent gasket and lid you could return in 10 years time and there would be jack wrong inside that box. When do you ever see a Galv install with PVC/IP Rated boxes throughout it? Just want to clear this up aswell, you would have to be a helmet to sink galv boxes into the ground.

 

[ackbarthestar]

Adaptable boxes look cheap and nasty. So where do Galv boxes stand on the numerous commercial buildings and industrial units our company has done to feed cables in galv conduit or SWA to outside lighting? Its crap, you're going to get condensation build up with what ever you install so it doesn't really matter. But i can safely say that if you make off all your glands correctly/tight and you a half decent gasket and lid you could return in 10 years time and there would be jack wrong inside that box. When do you ever see a Galv install with PVC/IP Rated boxes throughout it? Just want to clear this up aswell, you would have to be a helmet to sink galv boxes into the ground.

Agreed, never sink a galv adaptable box into the ground and in most cases you are going to get less condensation using plastic than metal and certainly less chance of nuisance tripping due to water build up.

I'm not sure what IP adaptable boxes you are referring to when you say they look cheap and nasty. Maybe you will enlighten us to their make?

As far as galv. adaptable boxes go, they are perfectly serviceable as long as you make sure you allow drainage for condensation. This is standard practice for any external wall mounted industrial/commercial installations.


My personal preference is to keep all connections out of the ground, unless put into a pit, for several reasons.
1/ easy to get identify
2/ easier to maintain

 

[trev]

Not yet Trev but My boss does most of the work for this letting agents up there and most of the landlords in that area seem to use this agents......we get quite a bit of work out of it ...which is always good ....but the amount of these "tennants" that just dont give a FxxK.......the places are always filthy and the tennants often are as well.....a lot of evidence of power pinching n all at a lot of these places....we went in one place and i aint joking when i say there must have been about 30 odd dirty plates and loads of dirty cups n stuff.....the cooker would have set alight if you had turned it on...the amount of grease n fat on it....dog ends everywhare and piles and piles of filthy clothes all over....now i really resent having to wade through all this ---- when on a periodic and that cooker.....we were supposed to pull that thing out as there was a damaged ccu behind it.....well i wasn`t touching that thing....got the tennant to do it......makes me feel ikky sometimes after going in places like that....euggh......

When I was on the bash in Gateshead there were a few houses that we flat out refused to work in, they really were that minging. Tenant liaison had fun with those ones, how do you tell someone tactfully that they're dirty stinking grimy buggers