Wiring for a 12volt lighting circuit

[campbeji]

I have read a few posts about lighting the house with a 12volt led lighting system. I'm just wondering how you get the power around the house? Are you putting in a new wiring circuit, or hi-jacking what is already there. I'm assuming its a new circuit, but if it is how do you get the cable around the house.

A bit of a diy guide would be appreciated.

Thanks
Jim

[caveman]

Jim,
I used the existing wiring. The only risk is that on long runs a heavy load will cause a slight voltage drop. If you stick to lighting with LEDs this will be an insignificant problem because the current draw is so low. 12volt CFLs should be fine also. For 12volt appliances I would be reluctant to use existing wiring as the losses would be significant. This is why many off-grid folks run their systems at 24volts. There is a really clever system which uses the 3 cores of conventional wiring to run a split +12 and - 12 volts with the ground as a 0 volts. This way at each point of use you can choose either of the 12 volts or use 24 volts (across both 12volt supplies)
here is a wee vid which shows this idea.
www.youtube.com/watch?v=m5rM7QDi_5E

I would not recommend mixing mains 230v ac and diy low voltage systems. Even if well labeled and documented there will always be a chance of a deadly mistake. I started by disconnecting all the lighting from the mains. So there are no 230v lights in that part of the house. The lighting circuit has no common connections with anything in the consumer unit. The low voltage distribution is completely separate from the mains.

[campbeji]

Thanks Caveman,

I must admit I'm not the most confident person when dealing with electrics in the house, so I'm not sure I would want to go down that sort of route, I'd hate to mess it up and end up frazzeled

I have a couple of questions, if you don't mind. Did you do the work yourself or get a spark to do it for you, I seem to remember hearing that the law was changed to stop people working on their electrics, or needing a certificate for new installations or something. If you have disconnected the 240v totally then you must have been pretty sure that your low voltage system was going to have enough power to keep running before swapping over, any pointers on how to specify what you'd need.

I'll have a look at the video.

Thanks

[cye]

i have taken an alternative approach and have not touched the original 240v lighting. i've used mains lighting flex (cheap white stuff sold in electrical suppliers) for the power cabling, and am gradually getting around the house with it. easiest to do the top floor first, as the cable can simply be popped under the loft insulation. with only a few watts per bulb or less, there is no risk of the cable overheating with the current even under a mass of insulation. the benefit if such a system is that you still have your mains 240v lighting if required.

in some of the rooms i'm using the twin cable suspension system to hang the LED bulbs from. this is ideal for a string of bulbs & it makes it so much easier than running separate cabling to every bulb.

with the whole setup running on 12v off a plug in switched mode power supply, it's safe as milk and building control is not required.

if you can hang a picture you can wire this stuff up.

i'll maybe put up a pic of one of the twin cable suspension systems if you like.

all the best

[campbeji]

Hi Cye,

Although I know what your saying here I don't really understand. I don't know what a 'twin cable suspension system' is so I would appreciate a photo.

As I see this there appears to be two options, 1/ replace the power to the current wiring system with low voltage and don't use the 240v, or 2/ Set up a new and totally seperate system for the low voltage.

I don't think I could justify the first option unless I was to spend more money than I have to get enough power initially and also hire in a spark to do the work (and that'd confuse most of the sparks I know).

The second option seems to be better suited to a piecemeal approach where I could add a little bit as funds permit, but I'd be worried about how all of the wiring would be fitted for switches etc. It seems like a big job to install new cables for everything, especially if there are to be hidden in walls and the ceiling, although I guess if you put it all into surface mounted trunking it would be easy enough.

Jim

[cye]

Jim,

Here's one example of the MR16 suspension systems available. The particular example here only allows for adjustment of the beam direction in one plane, but there are other systems which are more flexible. i will take a pic of one of the systems I'm using later.

These kits can be quite expensive, and I've an idea for a DIY version which should look fairly professional to those under 6' in height!

And for a really budget rail system, if appearance is not important, the bits and pieces needed are very inexpensive.

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