Ceiling lighting - switching from halogen to LED Ask questions and find answers to many subjects relating to electrics and electrical work

[gardner214]

Most of the ceiling lights in my house are GU10 12V - 50 Watt Halogen downlighters. I am not happy with them for a variety of reasons. The transformers are unreliable, they eat a lot of power and the bulbs run very hot, which is a potential fire hazard.

I've been advised to switch to mains-voltage GU10 LED downlighters, and I'm minded to accept this advice. However, rather than going for a "big bang" switchover, which would involve scrapping a substantial number of transformers and lamps that haven't failed yet, I'd like to make the switchover gradual - wait for a transformer to fail and, when it does, replace it with an LED lamp.

I have two questions: firstly; is there any reason why I should NOT switch over from 12 halogen bulbs to mains LED bulbs? Secondly, if I stick with my plan of switching over gradually, this will mean that, for a while, I'll have a mixture of LED lights and halogen lights running off the same lighting circuit. Will this cause any problems?

Thanks in advance for any advice received.

Gardner214

[stoneyboy]

gardner214,
Probably 2 issues - the cost of LED GU10s and the light level produced. You'll have to experiment with different makes to find the light level you want.
end

[ericmark]

Something is wrong. GU10 lamps are normally low voltage so don't have a transformer. MR16 are normally used for extra low voltage which in turn need something to reduce the voltage to 12 volt.

So with GU10 there is no problem with mix and match.

With extra low voltage it will depend on the device used to reduce the voltage. Although we call them all transformers often they are a lot more than a simple transformer and would be better called an inverter. The inverter may have both a max and min current and using LED lamps may draw less than the min current.

[gardner214]

I'm puzzled, now. Maybe I was wrong in describing my lamps as GU10 - I'm not a specialist in this area. I'll try to clarify.

Currently, each lamp is a 12V 50W Halogen downlighter. Each lamp is connected to its own transformer (although, as you say, inverter may be a better term) which converts the 240 V ac mains supply to 12V AC, which goes direct to the lampholder. I thought these lamps were called GU10s, but I may have been mistaken.

Anyway, I've been under the impression that there are LED bulbs available, which run off mains voltage, and are the same size and luminosity as the halogen bulbs, but which consume far less power.

My thinking was, that when of the 240V/12V transformers fails, I could, instead of replacing like for like, replace it with a mains-voltage LED unit. Initially, I would have a small number of LED units and a large number of halogen but, as transformers failed over time, I would install more and more LED units until, eventually, all the halogen units had been scrapped.

Can you think of any reasons why I shouldn't do this?

Thanks to all who have contributed so far, and thanks in advance for new contributions.

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[quote="ericmark"]Something is wrong. GU10 lamps are normally low voltage so don't have a transformer. MR16 are normally used for extra low voltage which in turn need something to reduce the voltage to 12 volt.

So with GU10 there is no problem with mix and match.

With extra low voltage it will depend on the device used to reduce the voltage. Although we call them all transformers often they are a lot more than a simple transformer and would be better called an inverter. The inverter may have both a max and min current and using LED lamps may draw less than the min current.

[ericmark]

If your lamps are supplied with a plain transformer then simple swap. With an inverter it would likely need the inverter changing to one designed for LED. But unless in a bathroom or some other safety reason for using extra low voltage (12v) then doing away with the transformer/inverter and changing to GU10 is likely a better option. With low voltage (230v) you have three types of lamp. Tungsten, Cold cathode, LED. These can be swapped easy and there is no need to mess around with transformers when you swap. So if you find LED is too dim easy to swap to cold cathode or tungsten.

Theory is the tungsten lamp has a thicker element when 12v rather than 230v so lasts longer also the inverter controls the voltage to very fine limits again extending the lamp life and slightly increasing efficiency. In practice only where the area has large voltage fluctuations does the lower voltage version work better. Once you stop using tungsten then there is very little point in extra low voltage. The only reason to use extra low voltage is where because of the zone in a bathroom it becomes a requirement.