Changing all halogen downlights - stick with GU5.3 or go GU10?

25 Feb 2012
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United Kingdom
I have 10+ halogen downlights in the house. They are 12v GU5.3 (MR16) with transformers. They have been in over 20 years and various parts are looking scruffy and even perishing, so I am going to change over to LED while renovating.

Are there any technical or safety considerations in going to 240v GU10 LEDs versus 12v GU5.3 LEDs?

If I change to GU10 I just need holders and bulbs, but if I stick with GU5.3 I will need bulbs and new transformers. Might as well just dump the transformers and go GU10 off 240v?

Any other considerations?
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GU10 is usually recommended as it's the simplest option. There's no messing about with transformers that can fail or cause issues with incompatible lamps etc. GU10 lamps seem to be far more common too with plenty of options for colour temperatures, wattage and beam angle etc.

Make sure the GU10 fittings that you choose are compliant with the location they are being installed and make sure they're safely installed by someone competent.
I would also say GU10 unless in a bathroom and the distance to shower or bath does not permit it. Since 20 years old you may have real transformers, if so you can simply plug in G5.3 which I have done in my bathroom, but the whole reason for 12 volt has gone with LED, there were two reasons to use 12 volt one was thicker filament so bulbs lasted longer, and when electronic transformers came out voltage correction also increased life, but reasons have gone with LED MR16 compatible lights.
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Do you intend reusing the cables which currently carry 12v ?
It will not have been a 12 volt cable used to wire in a low volt light fitting it would have been either 1.0 or 1.5 which is still the same used today. This is off course unless some diy numpty fitted bell wire or something equally as poor. The typical statement from someone when asked what size and type of cable is used (often reply just the ordinary one)

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