My understanding is that concealed junction boxes are not allowed according to the wiring regulations. Does this extend to lighting circuits? My DIY book (2001) clearly shows using junctions boxes under floorboards as an alternative to the loop-in system.
thanks for any help
Martin
It's not the junction box, but the screw terminals within that must remain accessible for inspection. It is my understanding that being located underneath liftable floorboards counts as accessible.
Christian.
Same regs, but I think the vernacular is not 'concealed' but 'inaccessible'. How you define that precisely is a moot point, but under floorboards etc is normally deemed OK, because floorboards can be lifted readily; whereas (eg) buried invisibly in plaster walls is not.
David
What about behind a kitchen unit? This is accessible but only if I dismantle half the kitchen to get to it! An accident with a power drill, frayed tempers and total fustration led me to this bodge.
Steve
My take on 'accessible' is you should be able to access it during an electrical inspection/test. I would not expect to be pulling out a fitted kitchen or removing fitted flooring coverings during an electrical inspection/test, which might happen on a house sale for example. Others may not agree -- there's no definition of just how 'accessible' it needs to be.
You can still join cables in inaccessible locations, but you should crimp or solder the joins. One way is to use a junction box in the normal way, and then solder the terminals/conductors too -- I've done this a few times, but unless you're competent with soldering, crimping is probably better, but you'll need a suitable enclosure. However, where possible avoid inaccessible cable joins.
I agree Andrew, but as I said it was definitely a bodge! Never done one yourself?
Steve
Hmm. Pretty well any 'replacement' light fitting relies on the loop in loop out and switch connections being on the 'other' side of the ceiling, so not readily available for a quick inspection. If this doesn't meet regs, why are they on sale?
But can you not simply remove the fitting and get access to all the connections?
No, cos typically the single cable to the light fitting comes through the ceiling via a small (single-cable-sized) hole, and the wiring connections are all inside a junction box or something similar, above the ceiling
David
The only tidy way I've found of doing these sort of fittings is to move the loop in ceiling rose into the ceiling void and run flex from that to the fitting. Or use a junction box. A series of choc blocks inside the new fitting - or pushed up into the hole - fills me with horror.
Not typical in the land where I live.
Most lights have a ceiling rose in which all the interconnections are done, nothing except wires in the void above.
Same here, but the question was about a scenario where the original fitting (ie a ceiling rose presumably) was being replaced (ie by a 'modern' fitting which doesn't want a rose)
David
I know someone who now has a 13A socket in a most pointless place after drilling through a cable...
He couldn't see the point of joining the cable inside a socket box and fitting a blanking plate, "you may as well have a socket there in case you ever want to use it"
I discovered that modern halogen fittings with integral transformer often have a very deep fitting. Just enough room to be able to unwire and remove the old lampholder from the flex from the ceiling rose, wire this to the terminals on the new fitting, then fix new fitting onto the ceiling with the old ceiling rose covered up by the fitting itself!
Luckily it was a fairly small low profile rose, most I've seen seem too big!
I push choco blocks inisde the walls and ceilings.
As long as they are done properly, there is no real alternative to making a neat connection.
I use junction boxes where I can, but thats not everywhere...
Or crimps inide plaster.
I had a hallway with 2 adjacent single sockets so that the ring could extend up into the loft for a few sockets and down for an additional double socket near the ceiling next to a built in bunk bed.
Fitting the second socket, which was lying about in a box anyway was quicker than buying a ratchet crimper, which I didn't have with me.
Christian.
Assuming the fixing screws don't want to go through the ceiling rose?
While this is common, it's not to be recommended. There should be two layers of insulation - hence a JB. Suppose you could use heat shrink sleeving or tape etc.
Personally, I'd not have any joint inside plaster. I'd replace the entire cable. But then most of my walls are stud types so easy to wire.
You can get dinky little 20A(?) junction boxes; 4 terminals inside a circular box about 50 mm diameter. They're particularly useful for wiring downlighters because you can bung them up the ~70mm hole you've just cut in the ceiling to take the fitting.
David
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