Halogen downlights

[Soup]

I\\\'m currently converting my garage and am installing 8 Mains Halogen downlights(50W) on a single dimmer (dimmer rating 600W). I\\\'m intend to connect to the existing ceiling rose and connecting the lights in series using 1mm2 cable ( recommended minimum ).

1. Should I use a cable that has a higher rating than the recommended minimum, i.e. 1.5mm2 or 2 mm2.

2. Will I need to change the existing ceiling rose to something more substantial to take 8 halogen lights ?.

Please advise

Soup

[ban-all-sheds]

Soup wrote:

I\\\'m currently converting my garage and am installing 8 Mains Halogen downlights(50W) on a single dimmer (dimmer rating 600W).

That's probably close to the limit for the dimmer (they usually need to be derated by 25% for halogen lamps, so your 600W dimmer would actually only cope with 450W). Don't be surprised if it buzzes.

Quote:

I\\\'m intend to connect to the existing ceiling rose and connecting the lights in series using 1mm2 cable ( recommended minimum ).

For some reason people don't like me pointing this out, but I'm firmly of the opinion that if you let one incorrect term drift by then sooner or later you get confusion that could be dangerous - it is important to always use words that describe what you mean, not what you don't mean.

You don't mean (I hope!!) that you will connect the lights in series, you will (I hope!) connect then in parallel.

Quote:

1. Should I use a cable that has a higher rating than the recommended minimum, i.e. 1.5mm2 or 2 mm2.

There's no such cable as 2mm. 1.0mm will be perfectly OK, and 1.5mm will bring you no benefits, unless you plan to have these lights a l-o-o-n-n-g-g way apart. BUT - you may have to use at least the same size cable as is already used for your lighting circuit. If it's 1.0mm, you may use 1.5mm if you want, but if it's already 1.5mm you may not be OK with 1.0mm for the additional wiring. What rating is the MCB/fuse? (and is it an MCB or a fuse?)

The safest idea would be to use 1.5mm if that's what the rest of it is.

Quote:

2. Will I need to change the existing ceiling rose to something more substantial to take 8 halogen lights ?.

I'm surprised you plan to leave it there - a bit ugly, no? But quite substantial enough - roses have to be able to pass the full current of a lighting circuit, which is at least 5A, and could be 10A.

__________________
I mustn't warn people that the "experts" on the plumbing forum can't be trusted to tell the truth.

[securespark]

ban-all-sheds wrote:

roses have to be able to pass the full current

Translation 1.

Electric flowers?


Translation 2.

Oooooh, I wish I hadn't eaten all that electricity....



Ok, Ok, I'll call the nurse........

[ban-all-sheds]

securespark wrote:

Ok, Ok, I'll call the nurse........

He'll be along shortly - he just needs to put on some latex gloves first....

__________________
I mustn't warn people that the "experts" on the plumbing forum can't be trusted to tell the truth.

[securespark]

[Soup]

Thanks for the reply. Sorry if the questions seemed wooly !!! The dimmer is actually rated at 600W for halogen lamps so no problem there.

I have actually moved the ceiling rose out of sight so no need to panic.

The issue regarding connecting the lights in series came from a friend who is a sparkie and also on the installations instructions it says to connect them in series. Is this right ?

[ban-all-sheds]

Soup wrote:

The issue regarding connecting the lights in series came from a friend who is a sparkie and also on the installations instructions it says to connect them in series. Is this right ?

It's absolutely not the right word to use, but what do you understand by it? How do you plan to link the lights together with the cable? If you, your friend and the installation instructions have all got the same idea of what the word means, even if it's the wrong meaning, then how they end up wired will probably be correct.....

Code:

SERIES: L ------{X}------{X}------{X}---                                 |                                 | N ------------------------------ PARALLEL: L -----------------------------          |        |        |         {X}      {X}      {X}          |        |        | N -----------------------------

__________________
I mustn't warn people that the "experts" on the plumbing forum can't be trusted to tell the truth.

[Soup]

Sorry, I've got it wrong. My fault. They are in parallel. I looked at the diagram again and can now see my mistake !!!