[Question] transformers for downlights

[markthespark]

Hi guys as we all know according to 7.9.4.1 "the primary terminals of the supply source shall be in an enclosure" for 50VA transformers of downlights. I need to rectify 70 of these at one home do I need to replace these transformers or are the plastic (not very practical) coverplates available??

[AndyD]

I'm not sure if the guys who work on domestic electrics have a trick up their sleeve or whether they just replace transformers with no terminal covers because I've never seen the covers sold separately.

They're pretty cheap so if it was me and it was just a couple of transformers I'd probably replace them in the interests of time but with 70 it seems almost criminal to condemn that many so I'd probably get creative.

Just thinking out loud maybe you could make 'enclosures' from a piece of trunking with a couple of end caps. You could make these up very quickly off-site but you'd need vent holes in the trunking to prevent overheating of the transformer.

Might be pushing the boundaries of the word 'enclosure' but what about wrapping the end of the transformer and the input terminals in self amalgamating tape. You could even heatshrink the entire end of the transformer, we have stock of heatshrink up to 50mm diameter but it's available in even larger diameters than that if necessary.

Like I say, might be pushing the boundaries a bit, see what the other members think.

[markthespark]

Thanks for the help Andy but either way to enclose 70 of them is going to take up some precious time. Would taping the ends up with normal insulation tape not solve the problem? I feel that insulation tape would be more difficult to remove than the petty plastic end caps and both of them would not require a "tool" to remove!

[Dave A]

Chatting to my electricians - There are some transformers where the terminal covers can be bought separately. For the others we either replace the transformers, or put then into York boxes with holes drilled for ventilation - depending on the economics.

[AndyD]

I think the taping of terminal connections would be inadequate to fulfill the 'enclosure' requirement, even self amalgamating tape TBH. I'd go with lengths of 50x50 trunking, also with vent holes drilled and with end caps.

[Leecatt]

Without having to search the regulations for the relevant passages, one must remember that all equipment used in electrical installation has to adhere to certain standards. All equipment has been certified and once that equipment is adjusted or altered it no longer adheres to the original certification standards.
Drilling holes into equipment that has a specific certification nullifies that certification. Of course homemade equipment has no certification and also has no place in any electrical installation.
As an example I once came across an installation where some bright Spark has used tin cans, normally containing cold drink, as covers for the exact same equipment we're discussing here.
As difficult as it may be for the person paying for it to understand, replacing those 70 Transformers with the correct type of Transformer would be the only way forward. Had the correct type of Transformer been installed in the first place the situation would never have happened.
As is normally the case in these circumstances the client has quite possibly taken the cheapest route originally and now has to pay to have it corrected.
Just my ten cents worth.

[AndyD]

.....Had the correct type of Transformer been installed in the first place the situation would never have happened......

From what I understood the existing transformers are of the correct type and are all functioning as they should be, I think it's just the little plastic covers or lids weren't fitted over the screw terminals by an installer that was too bone-idle lazy to do so.

[Leecatt]

From what I understood the existing transformers are of the correct type and are all functioning as they should be, I think it's just the little plastic covers or lids weren't fitted over the screw terminals by an installer that was too bone-idle lazy to do so.

That being said, if a new cover were to be constructed the device would no longer be classed as "approved equipment" and could not be used.
It's a hard pill to swallow but unless equipment is maintained correctly and kept in its original state, it must be replaced with another piece of equipment which meet with the required standards necessary.

[Dave A]

I remember going into my first walk-in luminaire enclosure so well. I turned to my IE who had designed and built the thing (a spectacular light box bedroom wall in a B&B) and said "Is it legal to have all that open wiring?"

"It's just a big luminaire enclosure, so yes" he replied.

I was impressed. I must say though, the fact that the enclosure had never been certified by SABS (or anyone else) never came up.

[AndyD]

I think it's a gray area. I'm thinking if all enclosures required SABS approval for their specific application there would be no shop or business signage because they're each custom made. Also if any deviation from an item's original spec was taboo then you couldn't drill holes in anything to install an appropriate gland for example.

[markthespark]

I agree with you Andy! It is only when you disturb the integrity of the item that it becomes a problem. Enclosing the end cover with a plastic shield which is secure and affords the requirements of the standard test finger then surely this will suffice!!

[SilverNodashi]

I think it's a gray area. I'm thinking if all enclosures required SABS approval for their specific application there would be no shop or business signage because they're each custom made. Also if any deviation from an item's original spec was taboo then you couldn't drill holes in anything to install an appropriate gland for example.

This is what irks me as well. Where does one draw the line between practical + affordable VS following standards, purely cause "it's a standard"?
Isn't it more important to have a secure installation, using what tools, materials and experience / training is available, than keeping with the standards ?

[Dave A]

When it comes to alteration of a product, one should take care to differentiate between "meeting a standard" and "certification". When you alter a product, no doubt it'll affect the validity of its certification. However, the product may still meet set standards.

And then there's also that wonderful argument that a roof void is an electrical enclosure to consider...