MR16 GU5.3/GX5.3 led lights

[hawaiianrobot]

Hi,

Please excuse me if this is a very basic question.

I've been attempting to replace some MR16 dimmable Halogen lights (Sylvania Coolfit) in a 12V 50W max GX5.3 Coolfit 50 ceiling recess with led lights.

I tried some GU5.3 12V led bulbs and they didn't work, and having put the Sylvania bulbs back, they don't work either now.

Before I call an electrician out, have I just picked the wrong bulbs or has something blown?

I would prefer to not have to get specialist/hard to find bulbs, if there's no real benefit.

Is it straightforward switching the fittings to a GU5.3 fitting, if that's the issue?

Many thanks!
Sam

 

[Murdoch]

Your transformers may not be compatible with the LEDs - older ones have a minimum load of 20w

 

[kerching]

GU 5.3 and GX 5.3 refers to the lamps, whether they are aluminium reflector so heat forwards OR dichroic reflectors Heat backwards.....not a lot of people know that, even less care

 

[BorisJ]

I tried some GU5.3 12V led bulbs and they didn't work, and having put the Sylvania bulbs back, they don't work either now.

Before I call an electrician out, have I just picked the wrong bulbs or has something blown?

I would prefer to not have to get specialist/hard to find bulbs, if there's no real benefit.

Is it straightforward switching the fittings to a GU5.3 fitting, if that's the issue?

Many thanks!
Sam

It is quite possible that while moving the Sylvania lamps backwards and forwards the filaments have broken, especially if they are old.

Replacing 12v halogen lamps with LEDs is fraught with problems and best not done.

If you have 12v transformers (real wire wound transformers) it will work.

If you have switch mode devices (often incorrectly called electronic transformers) there are two problems.

1. Switch mode devices generally produce 12v at 10s of KHz. LED GU5.3 are often marked DC or 50/60Hz AC. They do not like being run at 200 times their design frequency and not last long even if they work.
2. Switch mode devices are cheap and nasty (buy cheap, buy twice) and often have a minimum load requirement (they don't have to be like this, wall worts for electronic devices don't have a minimum load requirement). That minimum load is more than 5W of a typical LED GU5.3.

The best answer is to remove all the power supplies and change the lampholders to GU10, update the wiring to 3 core mains cable and fit 240v GU10 LEDs.

 

[Mike P]

12v LED require a LED constant current driver unit, otherwise they will not work.
You either need to fit the above or as stated by BorisJ you need to re cable and fit GU10 mains fittings

 

[Sparksfly]

Yep second that....RCD ......anyone ?......anyone ? (Economic Teacher in "Ferris Bueller's Day Off")

 

[BorisJ]

12v LED require a LED constant current driver unit, otherwise they will not work.
You either need to fit the above or as stated by BorisJ you need to re cable and fit GU10 mains fittings

12v LEDs require a 12v DC power supply. You can get current driven LEDs but they are not labelled 12V.

 

[Mike.J]

Wont be popular as its outside the manufacturers design, but these: https://www.toolstation.com/spare-lampholder/p93364? had exactly the same fitting distance, diameter and insulation to the old SES fittings I had, I am sure there is a solution to your conundrum, Oh yes I do not recommend doing this.

 

[Murdoch]

Wont be popular as its outside the manufacturers design, but these: https://www.toolstation.com/spare-lampholder/p93364? had exactly the same fitting distance, diameter and insulation to the old SES fittings I had, I am sure there is a solution to your conundrum, Oh yes I do not recommend doing this.

Hum ................ not sure , on face value, if this advice is very sensible

 

[Mike.J]

Said it would not be popular, but it is swapping out a 40watt or so SES to a 4 or maybe 5watt LED, its up to the individual, I would not recommend this in a customers premises, the only problem I have found is being an SES fitting it's recessed into the lamp holder, therefore the GU10 fitting is also, its a pain to fit the lamp, generally needs the fitting to be dropped from the ceiling to fit, not that I recommend doing this in the first place though.