Rating downlight transformers....

rocker · Feb 22, 2010

Here's a silly question. I've never put in a transformer-type light before, so bear with me please....

I=Watts/Volts, yea? But, when I am using a 35w halogen and a 240-12v transformer for each downlighter, do I work out the amperage as 35/12, or 35/240?? Or something else? 2.9 amps per light seems ridiculous, but is it? I've gotta put nine of the damn things in!

Well confused, any help would be appreciated.

andrew692003 · Feb 23, 2010

Evening lads!

LED's probably are the way to go but they are still quite expensive for Joe Public even though they will reap the benefits after a couple of years the initial outlay seems to be the problem. Anyway reading some of the replies in this post and other threads most of you tend to favour 240v GU10 over the 12v version. I have to say most of the houses we wire we advise low voltage generally because IMO 12v lamps are lnoger lasting and give of a sharper light than a GU10.

I can't think of one occasion in the last 3 or 4 years where we have had problems with any 12v lamps or transformers giving people trouble but I could give you a list as long as my arm of people who seem to have problems with the GU10 equivalant.

Just my thoughts!

Cheers

baldsparkies · Feb 23, 2010

I'm amazed Andrew, Thats a complete reversal of my experiences. Often its not the lamps its the transformers with 12v. At least with GU's you only have the lamp to worry about, but glad you get on with the tranny route, I think your one of the lucky few though.

andrew692003 · Feb 23, 2010

What make trannies do you use? I swear bythe 60va JCC with leads must have installed hundreds and very rarely have any problems! When I say rarely I mean only 1 or 2 have not worked straight out the box on first power up.

Cheers

marksparky · Feb 24, 2010

must say i also am with andrew 12v all the time, much sharper light and if installed correctly bulb life is quite good, must say i havent tried the led route is there good light output? or is it a case of sacrifice light for cheaper runnin costs?

andrew692003 · Feb 24, 2010

One of the last houses we did was a 2 storey new build, quite fancy with a lot of AV and audio work along with CAT5 computer ports etc. The architect wanted all downlights throughout the house with Megaman 11w GU10 LE Lamps!

I wasn't impressed at all, fair enough going green etc but this client was forking out a small fortune in Firerated downlighters and Megaman LE Lamps, I think it was around 90 -100 believe it or not. Anyway there was a distinct lack of light IMO compared with the LV equivelant. I like a lot of light so that maybe hinders me sometimes but I certainly wouldn't install LE equivelants unless I really had too!

As for LED lamps I did look into supplying GU10 and LV versions a couple of months ago to a customer but he thought they were too expensive, not sure about the light output but certsinly 3w and 5w seem to be quite good. I have thought about trying some in the sittingroom when its dark but so far no bloody time!

Cheers

toplightco · Feb 26, 2010

I tried an 8W multiple LED lamp this week - the light output was approximately equivalent to a 50 watt halogen but a very harsh blue light even though it was described as Warm White! I personally would go for the aforementioned LE GU10 lamps at least until such time as LED lighting has matured and come down in price....