Interior lighting: 12 Volt vs 240 Volt

Discussion in 'OT (OFF Topic) Forums' started by bolide, Oct 2, 2011.

  1. bolide

    bolide Hardcore MB Enthusiast

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    For interior downlighters what are the pros and cons of 12 Volt vs 240 Volt fittings? And low energy?

    I assumed 12 Volt setups used a central transformer but it looks like that is not the case

    While we're at it, could someone qualified to comment give me the lowdown on what electrical work non-qualified personnel can perform in their own house / bathroom / garden?

    Nick Froome
     
    Last edited: Oct 2, 2011
  2. jonnyboy

    jonnyboy Hardcore MB Enthusiast

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    Nick

    i would always always go 12v over mains voltage for downlighters, each one normally has its own transformer and has a "soft-start" which seems to massively increase bulb life.
    I've just fitted 50 or so fire-rated ones in hoods so if you want a decent supplier give me a nod
     
  3. finisterre

    finisterre Hardcore MB Enthusiast

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    Last edited: Oct 2, 2011
  4. OP
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    bolide

    bolide Hardcore MB Enthusiast

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    So what do most people do? Ignore it all? According to that link almost any work, even non-electrical, is notifiable

    There are lots of DIYers on this forum - do you all do all the red tape?

    Nick Froome
     
  5. Druk

    Druk Administrator Staff Member

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    What's 'red tape'? :devil:

    I have a good pal who was a senior airport maintenance electrician before he retired. He has none of this official crap to his name. Would i trust him to do my serious electrical work before any bona-fide sparky? You betcha I would.
     
  6. flango

    flango MB Club Veteran

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    I did all my wiring for the new kitchen extension and the conservatory also completely re wired the upstairs, there are so many loopholes in LABC it would be incredibly difficult to enforce. In fact many local authorities stances is if you take them on for refusal of a certificate they will back down as there is so many ambiguous area's. You just need to have the gonads to take them on in the first place :D If you are competent then I really don't see the problem
     
  7. corned

    corned Hardcore MB Enthusiast

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    I'm quite happy doing it myself. In fact, that's what I'm doing at the moment with our new kitchen/dining room. The builders have put in all the cabling because that had to be sunk underneath the new plaster work. That goes for all the sockets, lights, switches, everything. They put the cables and back boxes in, and I'm doing everything else.

    Incidentally, I opted for mains voltage lighting, mainly for ease of maintenance (i.e. zero). I can't abide the thought of having to go chasing out failed transformers up in the ceiling void. It happens. Also I wanted dimming, which is much easier to do with mains voltage fittings/lamps.

    For the record, most 12V systems I have come across have a separate transformer for each and every fitting/lamp. Lots to go wrong!
     
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  8. johnsco

    johnsco Hardcore MB Enthusiast

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    I have a degree in electrical and electronics engineering.
    I rewired my previous house (20 years ago).
    Sadly - It would be unlawful for me to do this now.

    It would be lawful to employ some unknown person who had the right piece of paper, who was recovering from a bad night on the beer and generally couldn't give a 4X.

    I recently got a new combi-boiler installed by someone with the right piece of paper for gas installations.
    What a scuffy job !!
    There were only 2 leaks on the system !!
    Solder running all over the place !!
     
  9. SPX

    SPX MB Club Veteran

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    Iirc in your own home, you have a bit of tolerance.

    Your problems would arise when you come to sell the house and the buyer would require Part P certificates etc.

    Likewise if you re-wired your house and it blew up, I'd be pretty sure your house insurance would be invalid.
     
  10. tim.100

    tim.100 Hardcore MB Enthusiast

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    I would go for 240v for two reasons:
    1) No power loss in the transformers
    2) Less current for the same power.

    In my case the 12v terminals got slightly corroded and got very hot - in fact one charred the ceiling joists. This could happen with 240v - but the connectors are better made and thus more fault tolerant.

    I'll be changing to 12v LED's very soon - just got some 45w equivalents for the shed (which is 12v) and they're excellent. Need 20 for the house though, so waiting for cost to fall a bit.

    If you do go for 12v - note that the transformers for halogen and LED are different, as the LED ones have a current limiter.
     
    Last edited: Oct 3, 2011
  11. corned

    corned Hardcore MB Enthusiast

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    Unless you plan to sell up soon, another reason for DIY is that yes, the Part P regs dictate that a qualified person must certify that the work has been done to the required standards, but (like me with my new kitchen this week) the work was done before the new regs came into force. Right Gov'nor? Nudge nudge, wink wink. ;)

    Now - remind me again what certification is required? :)
     
  12. clever dicky

    clever dicky Hardcore MB Enthusiast

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    Hi Sorry to drag politics into this thread, but as everything the last Gov. was f*@ked-up cant we just stick this prescott bull in the bin where it belongs. We had a perfectly safe and very good system before, and now with the wiring changes and the half dozen different certifications and regulatory bodies taking a slice, its become a joke. In years gone by anyone that could - did, as long as 16th ed was followed.

    But as has been said, for LED use a special pwr supply. I got some tiny ones off ebay after UK bought ones kept failing, and they are fantastic and less than a fiver each (from china).
    But have you considered using EL strips ? I'm just advertising some on ebay, that I got left over from doing sill lights.

    If not led is the way to go over halogen. Halved my electric bill replacing halogens everywhere. And much kinder on the eyes. Oh and another thing, your kitchen cupboards dont get so hot with led's that they melt the choccky biscuits.
     
    Last edited: Dec 25, 2011
  13. Dieselman

    Dieselman Banned

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    I wouldn't use regular halogen down-lighters in either 12v or 240v as they give a poor light and get incredibly hot due to being so inefficient. An incandescent lamp converts 95% of the input energy into heat, very little into light., as a result you have to be careful to not site them within 500mm of a flammable surface and to fit smoke foods if in ceilings.

    Use 240v florescent down-lighters or spots if that's what you want.

    I know someone who spends over £100 per year just illuminating the kitchen due to using halogen down-lighters and still complains of poorly lit areas.
     
  14. Dieselman

    Dieselman Banned

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    What colour is the cabling, I bet it's the new colours, in which case the work had to be done since the part-P reg came into force.
     
  15. clever dicky

    clever dicky Hardcore MB Enthusiast

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    Loads on EBAY.

    Just search - 'TWIN & EARTH CABLE OLD COLOURS'

    Wouldnt be surprised if it was still made. (much better system)
     
  16. marty359

    marty359 Hardcore MB Enthusiast

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    I'd use low voltage with a seperate transformer for each fitting, ive got 8 lv downlighters in our bathroom switched by a pir using quality transformers and lamps and ive changed 4 lamps in 3 years and as the bathrooms quite dark they switch in the day too. In the front room ive got commercial mains GU10's and when they go they take the RCD out :doh:


    the new colours came out before part poo came into effect ;) I dont do a lot of domestic work but the new t+e may now have a date stamp.

    A couple of years ago red and black t+e cable was fetching great money on ebay but sadly ive now run out of it :( Its alright doing your own electrical work but if its not safe to start with its just causing problems.

    And out of interest how many people have had their house tested in the last 5/10 years?
     
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  17. OP
    OP
    bolide

    bolide Hardcore MB Enthusiast

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    That's an interesting idea - lights on PIR. Hadn't thought of that! Ideal for a bathroom

    I've always wanted "submarine lighting" in my house - subdued lighting for night-time so when you stumble out of the bedroom at 5 am you don't get blinded as soon as you touch a light switch. Easy enough to do with a timer...

    Nick Froome
     

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