Replacing single light with downlights

[Bursar]

I'm planning on doing some work in my spare room to turn it into a cinematic place to watch films.

For lighting, I'm planning on pulling the single 60W light fitting and putting in half a dozen or so dimmable downlights. I haven't figured out if I'll be using halogens or not, I guess it will depend when I find the lights that I like the look of :)

I suspect each bulb will really want to be about 20W or so to prevent the room from being too bright when they're on full pelt. The plan will be to link all of the lights into one IR dimmer switch.

The act of fitting the lights doesn't worry me, and I guess the best thing to do is run the switch to a junction box, and then on from there to the lights. In that case I use new cable from the junction box. I'm more curious about the wiring that's already in place. Will it be OK to run these lights from the existing cable?

The house is about 20 odd years old (if that helps).

If it starts getting really compliceted, I might come up with a different plan. I really want to avoid channeling out the walls to run new cables.

[LV426]

Originally posted by Bursar
Will it be OK to run these lights from the existing cable?

Yes. Halogen downlighters come in two fundamentally different types - low voltage and mains.

For mains lamps, simply take the existing cable end-point (ie where the existing light fitting is), wire it into a connector block, and then run new cables from there to the new downlighters. Esure you connect all three cores - live, neutral, earth.

For low voltage lamps, you will also need one or more transformers. You can buy complete sets (typically consisting of a transformer, up to three light fittings, lamps, and a wiring loom). To get 6 lamps you need two such sets. Sets cost less than separate components.

Again, from the existing cable end point go into a connector block and then use the supplied cable(s) to run from there to the transformer(s), and the supplied loom(s) from the transformer(s) to the lamps.

IF you go the low voltage route (I think you will have to, for low wattage lamps - mains ones don't go below 50w I think) then you must ensure that your dimmer switch is rated for use with a transformer - they aren't all, but those that are work perfectly well.

[Bursar]

Thanks for that. Sounds like I should be OK in theory.

Originally posted by nigel
Esure you connect all three cores - live, neutral, earth.

have replaced a light fitting in our kitchen and dining room, and on both of those, there was no earth wire. Just the live and neutral.

I suspect the upstairs lights (where the HC will be) is going to be the same. Is this likely to be a problem?

[LV426]

Surprising - but perhaps an artefact of older wiring. Years ago, light fittings were made mainly of Bakelite - an insulating material - with metal parts relatively or fully unexposed. So no risk.

But, modern fittings (including downlighters, fluorescents, etc) are likely to be metal. The issue, then, is that, if the live wire were to work loose and touch the structure, the whole thing becomes live and dangerous. And you see that the light is no longer working, so you reach up to change the bulb and..........

An earth connection makes it safe, by shorting the live straight to earth in such an event (and blowing the fuse in the process - better than dying).

If your lighting wiring does not have an earth connection, I strongly recommend that you go low voltage. The sort where the transformer is separate from the fittings. At 24 volts, the risk of fatal shock from the fitting is nil. Mains voltage ends at the transformer (which will be hidden).

[Bursar]

Sounds like a plan to me :) Low voltage it is.

Thanks for your help.

[Bursar]

One more thing - The transformer supplied with the low voltage sets of lights says that it is dimmable, but the dimmer I was looking at in the Screwfix catalogue says it's suitable for mains voltage lamps only.

Do you know of any IR dimmers that will work with low voltage lamps?

[LV426]

They do exist........a web search will find. (I have a link, but not here, unfortunately). You could also try maplins.

[ReTrO]

I'm going to replace my current 2 60w downlights (on two circuits) with a circuit of 5 30w 240v halogens and an 8m run of ropelight. They will both be on IR dimmer controlled circuits, to save me falling out of bed trying to reach the light switch as I have to now. :grin:

I'll pop some piccys up in a new thread when it's all done.:smashin:

[Bursar]

Nice :) I'll look forward to seeing them.

I was tinkering with the idea of rope light, but I don't think it's worth it in my case.