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[carminelupertazzi]

I'm trying to fit individual halogen spotlights - GU10 50w - (from Wickes, 'no transformer required'), in place of similar existing spotlights. The change is purely for cosmetic reasons.
The wiring on the new lights is one brown and one blue. The existing lights are wired to one red and one black, coming from either the wall or the ceiling. I thought this would be straightforward - red to brown and black to blue - but I have fitted three so far and none work.
There are no switches on old or new lamps, all (should) work direct from wall switches.
Can anyone help please?

[pritchy1972]

are the bulbs working?

[carminelupertazzi]

[quote="pritchy1972"]are the bulbs working?[/quote]Thanks for replying. The bulbs are fine.
One thing though. the new lamps are clearly listed as not requiring a transformer and the halogen bulbs are bayonet fitting with 2 'bolts' at the tip. The previous fittings had different bulbs with 2 'pins' at the tip. I cannot check if they have transformers because the wiring is'nt accessible, but other lights with these 'pins' do. I guess this would explain the problem, although when I connected new lamps no fuses were tripped? Thanks again.

[matthewm1965]

If the old lamps that you are taking out had 'pins' instead of 'bolts', then they will be low voltage lamps with a transformer in the circuit.

You need to replace the lamp holders with the same type of pin connection.

[ericmark]

Following the British Standard recommendations transformers for low voltage lamps should be accessible.
132.12 Accessibility of electrical equipment
Electrical equipment shall be arranged so as to afford as may be necessary:
(i) Sufficient space for the initial installation and later replacement of individual items of electrical equipment
(ii) accessibility for operation, inspection, testing, fault detection, maintenance and repair.
But it seems this rule is often not followed and transformers are placed where they can be best hidden. Sometimes they are simply shoved in the hole for the light and with a little effort one can wangle them out of the same hole.
But from what you say I will suspect somewhere you have some transformers/inverters tucked away.
Once power is converted to SELV (Separated Extra Low Voltage) it does not require earth cables but with standard low voltage fittings (230 volt is Low Voltage) earths are often required and much depends on how original lamps were fitted.
You give no indication as to where or how the lights are fitted so can’t really give much help but if you were not able to distinguish between 12 and 230 volt fitting I would not think you have the skill required to change from 12 to 230 volt and I think your best option is to get an electrician to do it for you.
Eric

[carminelupertazzi]

Thanks for your replies Matthew and Eric. I had come to much the same conclusion although I agree with your assessment of my limitations Eric.
I am trying to replace 8 individual spots which I now know to be low voltage. 5 are controlled by one (dimmer) switch, 3 by another and 1 by another. All are on the same circuit which also feeds other lights. I can access transformers for the 4 and the 1 but the wiring for the 3 is wallbound (3 different walls) and access is not so obvious.
I agree with Matthew that the easiest solution is to replace the lampholders. But looking online, most individual (chrome) spots appear to be 230v and I cannot find any 12v I like.
Leaving the 3 for now, can I switch the 4 and the 1 to 230v by tracing the transformers back the the relevant spur and replacing with earthed 2core lighting cable?
Many thanks again, Carmine

[ericmark]

There is a move to "Energy saving lights". Discharge lighting will not work very well at extra low voltage and LED lamps seem to have a maximum of 3 watt so anyone with a bit for forward thinking will select fittings able to use discharge lighting (Also called florescent and cold cathode) even if not used with these bulbs now.
So the GU10 is becoming more and more popular however the cold cathode lamp is a little longer than its tungsten equivalent and care is needed to select fitting where when using the longer lamps they do not stick out in a manor to distract from their looks.
Eric