Access to transformers in ceiling -Regulations??

[Jquinn]

Hi,

I'm having low voltage spots put in my ceiling -5 lights running off single transformer. I'm trying to find out what the regulations ar regarding access to the transformers. Is it ok if the only way t access them is by cutting in to the plasterboard ceiling and the having to make good/repatch afterwards in the event of a failure -ver inconvenient admittedly, but is this permissable under building regs?

My builder says yes, but others have told me this is not allowed, an that I will need an access hatch of some sort -which I'd rather no have for aesthetic reasons. The transformers are too big to be pulle out of the spotlight holes by the way.

Any advice would be appreciated

-- Jquinn

[Lobster]

Well, junction boxes and the like need to be 'accessible' which precludes burying them under plasterboard. Given that there will be electrical connections to be made on your transformers, I'd say that they fall into the same category as junction boxes.

But anyway, regardless of what the regs say, I have to say I think you'd be nuts to bury them like this - they do (and will) fail, and you'll end up with a huge and disproproportionate amount of damage to put right.

What's above the room where you are fitting them? Can't you lift a floorboard and do it from above? I've used that approach before - had about 6 downlighters in a kitchen wired from 2-3 transformers IIRC, which I positioned close together under a single floorboard at the side of the room above (ie won't need to lift the entire upstairs carpet if I need access).

Alternatively - how big are these transformers?! I'm fitting some at the moment in (another) kitchen refurb and the ones I'm using (Screwfix ref 48058) are no more than about 20mm in diameter - certainly no problem to pop them up through the downlighter hole. What are you using?

David

[Grunff]

Regardless of what's permitted, it's a really silly plan. Transformers fail - it's not a possibility, it's a certainty. It's just a matter of when.

Use smaller transformers so you can pop them in through the holes.

[Andrew Gabriel]

They are usually designed to fit in through the holes for the lamps.

[The Natural Philosopher]

Nothing in the regs as far as I know on transformer siting.

Ive got one inside a stud wall..

[The Natural Philosopher]

You are joking? 5 minutes with a stanley knife, lift out plaster section, change transformer, put in small wooden blocks to set plasterboard back on, glue back with superglue, polyfill, wait a day, sand and splat a coat of emulsion on?

Hardly a huge job compared with some..

[The Natural Philosopher]

Indeed. The one that was replaced outside my house, when I got the supply undergrounded, had only lasted since 1936 without failure.

If you look at a trsnformer, you will see its juts bits of wire. (toroids anyway)If you look at your house wiring, you will see its just bits of wire. If you look at te transformer feeding your house, you willsee it basically juts bits of wire.

Obviously you need an access hatch to every cable, that runs underground or through a wall.

Bits of wire fail so quickly, its a sin!

And those electronics! Wow. I mean we need access hatches to every single undersea repeater in every single fibre optic cable thats ever been laid along the sea bed to the USA. Submarines are replacing them on a daily basis!!!..

Get real. Bulbs wear out. Wiring does not - not in the sort of once every 5 years schedule. My mothers house, built in 1953 and sold on last year, still had most of the original wiring, and switches and sockets. the original (electromechanical) meter..and the original fuse board.

If the OP is using a _reputable_ electronic, or better still large toroid, its likely it will outlast him.

[Nick]

For years I had a job rewinding burned out transformers. They have fine wire in them with thin insulation. They always get warm when they are in use. There's no way I would put one up in a ceiling, where it will set alight to your house if anything goes wrong. I know a lot of people do that, but I think they are mad.

[Grunff]

I knew someone would say that, I just knew it! My fault for not qualifying my statement. I was of course referring to switchers, not 'real' transformers. The majority of 12V halogen transformers are switchers these days, and they *do* fail quite frequently.

[Ed Sirett]

Then usual way is for the transformers to be 'posted' through the lamp hole.

[zymurgy]

Ok for you if you know where they are. How about the poor sap who comes along next ?

I too pushed the tranformer through the downlighter hole, so it's adjacent-ish to the lamp.

P.

[Dave Stanton]

They do fail from time to time, then they are dredged up, replaced and lowered back down. But they are built to rather more exacting standards than your average consumer device.

Dave

[Lobster]

Am I joking? Well personally I think you've just proved my point rather well! And as somebody else has said, your method assumes the location of the transformer is known. Plus, the OP is having all this work done by a builder, so if, as is likely, he's a non d-i-y'er the above would be more than a little challenging I suspect. Either that or he'll be calling in a sparks to repair the lights when a transformer blows - and what on earth will that cost?

And remember, all can be easily avoided just by selecting an appropriately sized transformer!

[The Natural Philosopher]

I'll be dead and gone by then. Not my problem :D

Actually its fairly obvious if you check which way the wires go from te switch..

Sadly some toroids are just too big..

[The Natural Philosopher]

About the same as when a cable in a wall needs replacing because it has 'burnt out?

See thread on trying to replace a coax cable in the wall.

I assumed we are talking to competent D-I-Y'ers here. If you live in a plasterboard house the first thing you learn is how to rip the stuff off, add battens and noggins and cables behind it, and repair invisibly and redecorate it.

Indeed, but that wasn't what the OP asked.

If you pick a RELIABLE transformer and site it sensibly, there is no reason not to make it 'permanent'

[Jquinn]

Ok thanks very much everyone for the help. I've now realised that if

make one of the holes just a little larger then I can just get th transformer through and still have the spotlight fit in correctly s the problem is solved. I'm still curious as to what the ter 'Accessible' officially means when used in the regulations though. i.e does having to cut through the plasterboard still officially count a accessible? While others have advised against it, I personally would b quite happy to do this and then repair in preferance to having t install an unsightly hatch in the ceiling -I just wanted to know i this is 'legal'.

Incidentally, they are electronic transformers, and whilst obviousl they are going to fail at some point, I've not had a problem with thos that I've installed in the past and would be happy to take the risk

-- Jquinn

[stopbox]

Hi Jquinn

Electronic transformer design has improved significantly over the last few years, as the circuits now provide surge protection, overheat protection and short circuit protection. However having done exactly what you suggested (before i was in lighting for a living!) to save a few quid, i did reqret it three years later, the day after i had put the flat on the market ... ended up having to repaint the whole kitchen.

The 'mouse' type electronic transformers have got much cheaper over the last couple of years ... our downlights, bulbs and transformers start at =A37.95 ... so it is a false economy.

- Jack

[jim_in_sussex]

reversible access with a tool, creating minimal damage, such as use of a screwdriver, spanner, a specialist anti-tamper tool, or a lock and key and the like.

so nailed boards, screeded plaster board, buried in a masonry wall, covers permanently glued in place, and so on are all excluded.

. i.e.

no - unless the plasterboard is an isolated piece screwed down and can be removed simply by removing the screws. However p/b simply screwed down like that won't last long as a removable cover & so probably fails the reversible test.

[Jquinn]

Thanks -that seams to answer my question.

Well in the end, I've found a small plastic hatch about 6inches squar that goes in the plasteboard ceiling to provide easy access whic doesn't look too bad.

And thanks Jack for the info, but as I said, it was an aesthetic issu as opposed to a cost issue

-- Jquinn