Wiring downlights which is better

gordsky · Posted: Tue Jul 24, 2007 7:33 pm Post Subject: Wiring downlights which is better

Hi,
Hoping someone can answer this. I am having 5 x 50w mains downlights fitted into my kitchen whilst the ceiling is being replaced. Have had 2 quotes from electricians but both offer different methods of how they plan to do the job. i'm assuming both are correct as they're both electricians just wondering if anyone had any thoughts on which is "better".

They both plan to replace the existing ceiling rose with a junction box.

The first stated he would use 1.5mm heat resistant rubber cable and go from JB to light 1 then from light 1 to light 2 and so on up to number five and finish at number 5.

The second plans to do the same but use 1mm heat resistant PVC cable and return from number 5 to the JB.

Anyone got any thoughts...?

Steve · Posted: Tue Jul 24, 2007 7:42 pm Post Subject:

tey should use the same cable the rest of the circuit is wired in. The JB needs to be accessible. A small JB which can bt pulled down through a downlight hole is fine. A ring of lights is pointless. End at no5.

50w downlights are very energy inefficient. Do you need 250w of light? Probably not, but you're forced to with halogen because of them making small pools of light.

Consider other lighting methods.

http://wiki.diynot.com/electrics:lighting:lamps:gu10

gordsky · Posted: Tue Jul 24, 2007 8:07 pm Post Subject:

Thanks crafty,

Any thought on PVC HR cable or the rubber alternative?

I think I will need all the lights as kitchen is 5m x 4m. Thought I'd rather go overkill and add dimmer later than under and have to add extra once ceiling is up (also I'm one of those people who likes everything in lines so would make more difficult to add extra later).

Steve · Posted: Tue Jul 24, 2007 8:19 pm Post Subject:

If you're going to add dimmers, I'd have the lights wired in sets of 2 and 3. This means you will need a max 300w per gang dimmer. Dimmers must be derated by half for halogen loads.

CallEdsFirst · Posted: Tue Jul 24, 2007 9:12 pm Post Subject:

Dont get involved with dimming GU10. Personally I hate GU10s anyway! They take the concept of a normal R7 Tungsten halogen, with a long spiralled and coiled filament and coil it again into a tiny space, generating loads of heat in a lamp that lasts probably less than 6 months before you dim it! 2000 hours compared to Low Voltage dichroics at 3500-4000 minimum.

Is HR flex a new thing for downlighters? I thought 309xY and 318xTQ was for boiler/immersion connections. T&E is good to 70 deg C and the HR flexes are good for 85 deg C. I thought the internals (obviouslt not the fitting itself!) of a TH lamp ran at up to 500 deg C. Even silicone rubber sheathing is only good for 180 deg C and glass fibre braid for 260 deg C. Whats the point?