Layout of Bathroom downlighing

[F1yTrap]

I am installing extra low voltage (12v) halogen down-lighting in my bathroom please can you advise if the following setup is ok. Essentially, is it safe to use the switched 1.5mm T+E live to supply 6 transformers as shown in the following diagram:

Untitled

• F1yTrap
• 21 May 2011
• 1

would I be right in thinking that if 50W bulbs were used (I intend to use 35W bulbs) then the max load on the Switched live cable would be 300W/240V = 1.25A Max load?

 

[holmslaw]

..

 

[F1yTrap]

Thanks holmslaw.

Taking the layout a bit further and including an extractor, does the following look sensible. I intend to mount all the transformers on a wooden board which I will fix above the loft insulation.

Untitled

• F1yTrap
• 21 May 2011
• 1

Does this look ok?

The downlighters are IP65 rated but I dont think they are fire rated: http://www.screwfix.com/p/fixed-white-12v-low-voltage-bathroom-downlights-pack-of-3/34883

I do want to insulate around the lamps so I was thinking of fitting a fire hood similar to http://www.screwfix.com/p/halolite-downlight-fire-hood-150mm/70589

 

[bernardgreen]

If you can mount the board vertically so there can be air flow over the "transformers" to increase the cooling of them.

Use a fire resistant board as a failed transformer can get very hot and in worse case ignite.

Do not put them close to each other. space at least two inches apart to prevent over heating and (possible ) interaction between them.

You cannot parallel together the outputs of the "transformers" as shown.

Six separate pairs of terminals, one pair for each "transformer" ( 12 terminals in all )

 

[riveralt]

Nothing to stop you using 1mm cable - it will save you a bit of money toward your electricity bill. The fact you are using six lamps @(210w or 300w) when one proper lamp at 60w would do, should tell you all you need to know - never mind about heat loss or fire hazards. Incidentally, I would use heat resistant cable for the link to the lamp.

You seem to have introduced chocboxes into the equation - not sure why?
You will need to check with the tranformer instructions - most set max limit on the length of cable between the transformer and the lamp.

You also need to check whether they can/should be fitted in a box - transformers, like downspots, do get hot and need to be able to disappate that heat.

 

[F1yTrap]

You seem to have introduced chocboxes into the equation - not sure why?

Just to house the 2 strips of connecting blocks for connecting to the lights.

The back board is just chipboard but the cables to the lamps will be using heat resistant flex.

 

[riveralt]

As I said, the manufacturers instructions need to be read to determine the min and max length of cable from the transformer to the lamp.
In your design 2 with the choc blocks you may not achieve this - better use design 1 for the lights - forget the chocboxes.

Your transformer needs a lot of ventilation - do not cover it in a box - see the attached instruction sheet for a 60v 20/60 electronic transformer.

http://greenbrook.co.uk/product-pdfs/ETR60_Ins.pdf

Don't forget if you fit it yourself and/or not in accordance with the manufacturers instructions its a good excuse for the manufacturers to refuse you guarantee.

 

[ban-all-sheds]

I am installing extra low voltage (12v) halogen down-lighting in my bathroom please can you advise if the following setup is ok.

Given all of your questions, were you able to convince the council that you'd be able to comply with P1? What did you say would be the way that you'd do that when you applied for approval?

 

[mbga9pgf]

I am installing extra low voltage (12v) halogen down-lighting in my bathroom please can you advise if the following setup is ok.

Given all of your questions, were you able to convince the council that you'd be able to comply with P1? What did you say would be the way that you'd do that when you applied for approval?

BZZZT! all I can hear is noise!

 

[DetlefSchmitz]

I am installing extra low voltage (12v) halogen down-lighting in my bathroom please can you advise if the following setup is ok.

Given all of your questions, were you able to convince the council that you'd be able to comply with P1? What did you say would be the way that you'd do that when you applied for approval?

What we need is a model answer. So, BAS, when you did that work in your kitchen, that work in your bathroom, and that work in your garden, respectively, what did you say would be the way your would comply with the law, when you applied for approval? I'm sure it would be a great help to many people to find out how a law-abiding person does it.

 

[ban-all-sheds]

Introduction



Please note that the reason for advising you about Part P and the notification requirements in the Building Regulations is not to hide behind the law as an excuse for not giving advice.


The concern of this site is safety and the giving of good advice, and part of the latter requires telling you about the law because ignorance of it is no excuse, as they say. There has never been anybody prosecuted for not notifying, the concerns are:

• Not having the right documentation when coming to sell your house. Buyers and their solicitors are getting more savvy, and if you've been through even one sale you'll know that a buyer will always be looking for reasons to get the seller to drop the price. No completion certificate for the electrics in the new kitchen or bathroom etc would be a jolly good reason.
  
• Doing electrical work as part of a larger project, e.g. an extension or loft conversion. Even now, several years after the introduction of Part P we still see people arriving here with tales of woe about having done the wiring for an extension themselves and now Building Control won't give them a completion certificate.

If as a fully informed decision you decide to ignore the law, then that's up to you - it's not the job of this site to enforce the law.


But neither is it to tell you how to do things which could have implications for you without making sure that you are aware of the law.


So what I do is up to me.

What anybody else does is up to them.

I start on the basis that people I don't know are law-abiding citizens. Would you rather I assume that they are not?

If you prefer, I could reword my post:

I am installing extra low voltage (12v) halogen down-lighting in my bathroom please can you advise if the following setup is ok.

Given all of your questions, do you think that you'll be able to comply with Part P, as the law requires?

Did you apply for Building Regulations approval in advance, as the law requires?


Is that better?

 

[JohnW2]

....- it's not the job of this site to enforce the law.....

....If you prefer, I could reword my post:

I am installing extra low voltage (12v) halogen down-lighting in my bathroom please can you advise if the following setup is ok.

Given all of your questions, do you think that you'll be able to comply with Part P, as the law requires?
Did you apply for Building Regulations approval in advance, as the law requires?

Is that better?

Probably not much (better) - particularly the second question. As you say, it's not the job of this site to enforce the law, and I think that can be extended to saying that it's not the job of this site to act as 'detective', either. There's absolutely nothing wrong with your 'pointing out' the legal situation to posters, and that is valuable for those who are not already aware of the situation. However, I think it would probably be regarded as 'better' if you 'told', rather than asked questions 'in public', particularly questions which effectively ask 'did you break the law?'.

That's how I see it, anyway.

Kind Regards, John.

 

[F1yTrap]

I have completed the work based on the advice given. Thank you to all posters that gave me excellent advice.

Thanks ban-all-sheds for pointing out the legal requirements of this work. I have not applied for approval or notified anyone of the work.

My entire house was rewired 5 years ago by a reputable local firm - almost every fitting I removed since has had at least one loose wire pop out when I remove the covers. I have also found cables with damaged sheathing under floor boards.

For this reason I have chosen to do the work myself. I take my time and always follow advice from experienced practitioners. I'm completely confident in the work I have done - much more confident about the the rest of the houses wiring which was carried out in compliance with the law.

Is there anything I can do retrospectively that would make my work compliant?

 

[ban-all-sheds]

Nothing realistic.

 

[holmslaw]

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