Buried junction boxes regulations

[Rodger Quinn]

Hi there, I am looking for some info on the current regs regarding the burying of junction boxes in my garden for outdoor lighting on a retaining wall.

The junction boxes will be behind the retaining wall. I am using 3 core SWA and ip66 boxes.

Upon reading some info I have picked up that junction boxes must be accessible at all times with the caveat that maintenance free boxes can be used.

Can someone clarify if this is the case for underground outdoor setups as well? Will I need to buy MF boxes lest I make my current boxes accessible for testing etc?

Thanks

Rodger.

 

[Pete999]

Hi there, I am looking for some info on the current regs regarding the burying of junction boxes in my garden for outdoor lighting on a retaining wall.

The junction boxes will be behind the retaining wall. I am using 3 core SWA and ip66 boxes.

Upon reading some info I have picked up that junction boxes must be accessible at all times with the caveat that maintenance free boxes can be used.

Can someone clarify if this is the case for underground outdoor setups as well? Will I need to buy MF boxes lest I make my current boxes accessible for testing etc?

Thanks

Rodger.

Think you have answered your question, I'm not sure it the box has to be maint free, but the internal connections certainly will need to be maint free, perhaps someone else can enlighten both you and me regarding the actual box itself, remember the box needs to be selected properly for whatever environment you are installing it in.

 

[Wilko]

The MF standard (BS5733) is pretty tough with lots of testing and so it's expensive for the manufacturers to qualify. A fully compliant set up is for the whole accessory - the box and connectors together. If your JB were compliant, the box would be marked MF, and I'm not aware of anyone doing an IP66 one(?). Best move would be to keep the JB accessible or make a permanent joint as per reg 526.3 .

I found this IET note helpful :
http://electrical.----------/wiring-matters/42/junction-boxes.cfm?type=pdf

 

[Pete999]

The MF standard (BS5733) is pretty tough with lots of testing and so it's expensive for the manufacturers to qualify. A fully compliant set up is for the whole accessory - the box and connectors together. If your JB were compliant, the box would be marked MF, and I'm not aware of anyone doing an IP66 one(?). Best move would be to keep the JB accessible or make a permanent joint as per reg 526.3 .

I found this IET note helpful :
http://electrical.----------/wiring-matters/42/junction-boxes.cfm?type=pdf

Thanks for that Wilko never to old to learn are we? as an edit, would an metal adaptable box say 4"x4", with Wagos as the connection medium be classed as MF?

 

[Risteard]

Thanks for that Wilko never to old to learn are we? as an edit, would an metal adaptable box say 4"x4", with Wagos as the connection medium be classed as MF?

I believe that Wago connectors are only considered MF when used with the appropriate enclosure. (WagoBox?)

 

[Wilko]

No worries

 

[Pete999]

I believe that Wago connectors are only considered MF when used with the appropriate enclosure. (WagoBox?)

Thanks mate, seems odd though, but I don't make the rules, so in conclusion, for it to be a truly MF joint both box and connectors have to be MF?

 

[Andy78]

Hi there, I am looking for some info on the current regs regarding the burying of junction boxes in my garden for outdoor lighting on a retaining wall.

The junction boxes will be behind the retaining wall. I am using 3 core SWA and ip66 boxes.

Upon reading some info I have picked up that junction boxes must be accessible at all times with the caveat that maintenance free boxes can be used.

Can someone clarify if this is the case for underground outdoor setups as well? Will I need to buy MF boxes lest I make my current boxes accessible for testing etc?

Thanks

Rodger.

I would advise against burying connection boxes unless they are specifically designed for the task. Even an IP66 box filled with water repellent gel can be the culprit of a failed circuit in not too long at all.
Any cables you bury will need to satisfy the regs regarding buried cables as well. I would consider getting an electrician to design, install and test this project for you.

 

[Barry White]

If I bury I use resin joints seen too many joints filled with silicone, gell or other gunge all will fail eventually and will be a pain to sort.

 

[Andy78]

If I bury I use resin joints seen too many joints filled with silicone, gell or other gunge all will fail eventually and will be a pain to sort.

Ahuh. Last ones I saw were IP66 boxes with good quality compression glands, all nipped up tight and filled with "magic gel". IR readings were through the floor after 18 months of being installed.

 

[westward10]

Would definitely use steel boxes, at least that way the armour may get earthed. Keep them accessible with Wagos inside.

 

[Rodger Quinn]

The boxes I have are plastic, using external gland kits and had intended buying the piranha type nuts to carry through the earth for the steel.

Sounds like resin joints are more reliable anyway so I think I will rethink and use them. I take it I can tee off from a resin joint kit? Any particular recommendation to use?

I did think about getting an electrician in to do the work but I like doing things myself, learning the proper way to do the job and carrying out the work, it's satisfying. Even if that means I'm rolling about the solem of the house or trawling the internet for answers

The job will be inspected, tested and certified before burial by a certified electrician so that I can add the certificate to my current building works completion.

The replies are much appreciated, thanks for the help.

 

[Midwest]

You could try the plastic bag IP rated joint box

 

[Midwest]

I did think about getting an electrician in to do the work but I like doing things myself, learning the proper way to do the job and carrying out the work, it's satisfying. Even if that means I'm rolling about the solem of the house or trawling the internet for answers

The job will be inspected, tested and certified before burial by a certified electrician so that I can add the certificate to my current building works completion.

Sounds like the work is part of building work subject to planning or building regs, or the equivalent in Scotland where I believe you are from OP? The circuit could also be new? I'm not sure where Scotland is with third party inspection & testing, so you might need to tread carefully.

 

[westward10]

Don't want to be using biodegradable bags for that.

 

[sparkdog]

I use Pratley underground boxes.

 

[Rodger Quinn]

Sounds like the work is part of building work subject to planning or building regs, or the equivalent in Scotland where I believe you are from OP? The circuit could also be new? I'm not sure where Scotland is with third party inspection & testing, so you might need to tread carefully.

This is a consideration I hadn't foreseen. I will contact the council tomorrow and get confirmation on that, thanks.

 

[Octopus]

Would definitely use steel boxes, at least that way the armour may get earthed. Keep them accessible with Wagos inside.

Like this one I found yesterday when doing some fault finding.... NOT!

 

[haj]

I believe Wago now do an IP rated box

 

[Andy78]

I believe Wago now do an IP rated box

They do the Wagobox capsule, but like all boxes, the IP rating is only offered as the box is sold, and is compromised as soon as you drill and add your own glands. It's up to you to make sure your cable entry method maintains a similar IP rating.

 

[Risteard]

Thanks mate, seems odd though, but I don't make the rules, so in conclusion, for it to be a truly MF joint both box and connectors have to be MF?

Sort of. It's maybe the enclosure rather than the connectors which are certified "MF" - but that certification only applies when used with the specified connectors (in this case Wago connectors in the WagoBox). I suppose it's down to how the unit was when it was granted MF certification. So to use something else inside it would negate that.

 

[Risteard]

I use Pratley underground boxes.

I bet your bank balance doesn't like them though!

 

[sparkdog]

Expensive but does a proper job.

 

[Rodger Quinn]

Thanks for the replies, folks.

I have contacted WAGO direct about their IP rated capsules and connectors to make sure they carry the BS5733 marking and the MF logo. If they confirm, I'll place an order with them.

I do wonder if an empty box has to have a particular specification to meet MF spec, and what that may be, or whether it's more to do with the type of conductor securing methods utlised inside that deem it's suitability.

Regards

Rodger

 

[Wilko]

I do wonder if an empty box has to have a particular specification to meet MF spec, and what that may be, or whether it's more to do with the type of conductor securing methods utlised inside that deem it's suitability.

Regards

Rodger

Hi Rodger - the MF logo is seen on the box (if it's an approved one) but for the joint to be 5733 rated as MF, it must have been standards tested and approved as a unit, i.e. connectors and box tested together. So a Wago MF marked box does not make a MF accessory when used with Wago 221 connector for example, as this connector is not yet certified as MF, afaik.

 

[Rodger Quinn]

So technically even the wago capsule can't be rated as MF since it isn't supplied with connectors.

 

[Rodger Quinn]

Reply from wago

Hi Rodger, The Wagobox-Capsule is an adaptable enclosure so you need to cut holes to fit glands to suit the cable you want to use. Consequently BS 5733 MF isn't an applicable standard for this type of enclosure. Bear in mind that the Wagobox-Capsule is designed to be maintainable solution for applications like garden lighting. It can be shallow buried with the appropriate glands but is not intended for deep buried permanent joint applications where you would more typically use a resin filled joint. Hope this feedback is helpful. Please don't hesitate to give us a call if you would like to discuss this further. 01353 666011.

 

[Wilko]

Yes, I think posts 26 and 27 are correct. With my tin hat firmly in place, I try my best to avoid underground cable joints in domestics, as it's usually a cost/time vs longevity. But if necessary to effect a repair I use a resin filled underground cable kit something like these below.

http://www.screwfix.com/p/prysmian-...tracking url&gclid=CKGOl9W27tACFcy17Qodd7YIHQ

 

[Rodger Quinn]

Yeah, I've pretty much resigned myself to using resin joints. Of course, I need the T or Y branch sort which seem to have attached quite the price increase compared to the straight through type. Just my luck.

 

[jackhammerJIM]

Yeah, I've pretty much resigned myself to using resin joints. Of course, I need the T or Y branch sort which seem to have attached quite the price increase compared to the straight through type. Just my luck.

If you are Teeing off in flex use a through joint . Drill a small hole in the top of the jointing kit for the flex . The resin will seal the hole .

 

[Rodger Quinn]

I've already ordered the branch kits

 

[soms]

Not sure about the Prysmian ones but have witnessed two 'Y' resin joints from the wholesaler which were a complete mare, cheap flimsy case with no cable retention whilst performing terminations, so little space to get stuff arranged and such awkward terminations. Then you tape the ends up to hold the resin whilst it sets. Unbelievable really.

 

[Rodger Quinn]

Even the 3M, assuming good quality, ones I saw on Youtube had the ends taped with self amalgamating tape to seal the ends.

 

[Wilko]

Not sure about the Prysmian ones but have witnessed two 'Y' resin joints from the wholesaler which were a complete mare, cheap flimsy case with no cable retention whilst performing terminations, so little space to get stuff arranged and such awkward terminations. Then you tape the ends up to hold the resin whilst it sets. Unbelievable really.

I think you have correctly described them

 

[Andy_G]

I

Thanks mate, seems odd though, but I don't make the rules, so in conclusion, for it to be a truly MF joint both box and connectors have to be MF?

think if the joints are maintenance free but the enclosure wasn't,then that would soon render the 'maintenance free' joints as in need of maintenance, therefore all parts of the system will need to be maintenance free. A chain is as strong as its weakest link is the best analogy I can think of

 

[telectrix]

pretty old hat now, mixing resin and pouring it in, when there's better solutions around. i.e. gel-filled torpedoes that you just make the connections and close the 2 halves together.

Under Ground Cable Joints and Glands - https://www.tlc-direct.co.uk/Main_Index/Cable_Accessories_Index/Cable_Joints_1/index.html