GU5.3 12v or 240v - how to identfy

[JohnW2]

OK, So what should I be looking for to power 6 leds in a string of 30watts (2.5A), if a 30w unit is too fine.

It's sensible never to run anything to it's absolute limit - If you weighed 100kg, would you be totally comfortable buying stepladder which said "maximum 100kg"? Anything above 30W would give you a bit of leeway - 40W or 50W ought to be fine. However, remember my other comments about uncertainties, which exist even if the power capabilities are 'generous'.

Kind Regards, John

 

[333rocky333]

Another thing that may have beeen hindering there operation is the length of cable run at 12 volt, these units are not really designed for over 2 metre runs, though this is mainly for EMC reasons, it could possibly also impact your leds.
Where will you site this 40 watt driver, a decent make one is unlikely to fit through a downlighter hole, it would proberly be better just to change the 6 lights to made up sealed lamp, led fittings, you already have the 240 volt at each point.
The fittings have a built in driver, so all is compatible, and likely 5 to 10 year warranty.
Youd likely get the 6 for under 100 pound

 

[utterlydiy]

Right,

Following some advice regarding a power supply for a replacement of my power transformers or whatever you want to call em.

Anyone who wants to change from Halogen to LED and have problems with flashing leds etc. due to a non-compatible transformer, Don't get a LED Driver as it won't work. The led lamps you get from the high street etc rely on a AC power source, not a DC supply as from a driver. Another forum gave me the advice in simple straight terms about the power supply for the 12v led requirement without all the fuss of GU5.3 specification or whatever.

After wasting time and money doing this and that, I replaced the 12 GU5.3 holders and transformers, with GU10 holders and earthing all the fittings. Got the holders from a wholesaler and lamps from Screwfix all for under £45.

So anyone who want to change from 12v Halogens to LED, dump the existing holders with the power source and replace with GU10 holders and LED lamps or replace the ceiling fittings as a whole. Whichever way you wish. But ensure the ceiling fittings are Earthed for 230v use.

 

[Observer]

OK,

So what should I be looking for to power 6 leds in a string of 30watts (2.5A), if a 30w unit is too fine.

I have many 12v halogen MR5.3 fittings all with separate transformers, mostly 20-50W. I started to replace the lamps with LEDs several years ago and found that some started to flicker immediately or after some time. The fix to that was to replace the transformer with one rated 0-50W.

This worked up to a point but I still had problems with the failure rate of the lamps - certainly not the 10000 hours or more that was promised.

I have recently started replacing all the SELV MR5.3 fittings with GU10. The main driver for this is that the latest LED lamps do deliver the same or more light than a 50W halogen, at 1/10 energy and no heat. The second, but in some ways first reason is that fashion for the appearance of the fittings has moved on. I fitted the 12V when the fashion was for the light fittings to be a decorative feature so brass or bright chrome or brushed stainless steel or gunmetal. That is no longer true (or not in my house anyway). So all the new fittings are (or will be) white or whatever blends with the ceiling colour.

I now have bucket loads of old 12V transformers, fittings and lamps, mostly serviceable.

 

[winston1]

I have many 12v halogen MR5.3 fittings all with separate transformers, mostly 20-50W.

I now have bucket loads of old 12V transformers, fittings and lamps, mostly serviceable.

They don't sound like transformers because transformers don't have minimum loads like that. They appear to be SMPTs.