Halogen ceiling spot lights

vaughan198 · Post by **vaughan198** » Sun Apr 05, 2020 4:34 pm

Hi,
A quick question from a newbie.
I have seven halogen lights in our lounge. Two of them haven't worked for a while and I just left them as was not that big a deal. Finally got round to sorting them out.
I tried changing the bulbs but that had no effect. I friend said I should change the transformers in the ones that were not working. I ordered them online and changed the transformers and they then all worked.
Success I thought! They worked perfectly for two days then suddenly all of the seven lights stopped working (when it was only the two broken in the first place).
I wonder what the issue could be. There is no switch in the wrong place on the main fuse board. COuld there be another fuse somewhere? Could I have mis-wired one of the transformers? It just seems odd that all of the lights stopped working at the same time (a few days after I changed two transformers).
I even looked at the switch (three dimmer/switches on the switch plate). And moved the celing circuits to another one to see if it was the switch which it wasn't.
Any help would be hugely appreciated.
Thanks,
W

Someone-Else · Post by **Someone-Else** » Sun Apr 05, 2020 5:06 pm

i have my suspicions..........

Pictures please.
The transformers, the light fittings and what watt are the lamps?

vaughan198 · Post by **vaughan198** » Sun Apr 05, 2020 5:26 pm

Attached are the pics of the transformer and bulb with a GU 5.3 fitting. Many thanks!

vaughan198 · Post by **vaughan198** » Sun Apr 05, 2020 5:27 pm

And each bulb has its own transformer

Someone-Else · Post by **Someone-Else** » Sun Apr 05, 2020 6:18 pm

............and the transformers? I did ask.

vaughan198 · Post by **vaughan198** » Sun Apr 05, 2020 6:27 pm

Sorry. That white box is the transformers that I replaced (same models). I will send now

vaughan198 · Post by **vaughan198** » Sun Apr 05, 2020 6:29 pm

Here are the transformers. This is an extra spare one.

Someone-Else · Post by **Someone-Else** » Sun Apr 05, 2020 10:25 pm

Can you post another picture of your spare transformer. One that I can read what is printed on it.

I am not being pedantic, in order to help you, I need to know what you have, but if I can't read what is printed.............

ericmark · Post by **ericmark** » Mon Apr 06, 2020 4:11 am

I say you swapped dimmer so not that, so it would seem likely a wire is dislodged, it is a problem with the electronic transformers that they don't have through terminals, so some where the wires need to be joined, ideal is something like this

where the cables are clamped, however in the real world more likely something like this

wrapped if your lucky in tape.

Given the rest seems suspect, think very likely a wire has worked lose. The electronic transformers you show are not simple transformers, they also control the output voltage as with a quartz lamp it is important to get maximum life that the voltage is spot on, too high as you will likely realise the filament will rupture, but also too low and the active material tungsten is deposited on the quartz envelope instead of back on the filament turning the quartz black and reducing lamp life, so quartz lamps should not be dimmed, they often are, but it reduces the bulb life.

7 x 50W = 350 watt or often called 350 VA that is some 1.5 amp at 230 volt which is a lot for lighting, in the main lighting is a total of 6 amp as ceiling roses and some switches are often only rated at 5 or 6 amp, so although permitted up to 16 amp for lighting, in real terms normally 6 amp is the maximum, so the dimming switch may have been overloaded and also the protective device may have been overloaded. That is fuse MCB or RCBO with the latter some makes you need to switch off to switch them back on, and they are designed so they can't be forced on, so some times they can look as if on but are not on, you can normally feel when they are faulty, you feel the resistance to switching on drop before latched on, so switch a good one off/on to feel what it should feel like, then try the faulty circuit to see if it feels the same.

The lamp you show comes in 10, 20, 35 and 50 watt, in fact there is also a 75 watt version although not often seen, your electronic transformer is rated 20 - 60 VA so it could have very likely originally had 35 watt lamps, or even 20 watt with no dimming switch, often dimming switches auto close down with overload, so worth removing some bulbs in case dimmer switch is overloaded.

I have seen where 10 watt lamps were originally fitted using a 60 VA transformer to supply 5 lamps, and since the bulbs look the same, 50 watt have been fitted in error.

The idea was to heat the room with the lights, not a bad idea as it goes, radiators provide back ground heat and heat the air, and the lights boost the temperature perceived with radiant heat which the wall thermostat or TRV will not measure, so instead of heating room to 20°C you heat room to 18°C and the heat from lights makes it feel like 20°C when switched on, so since the air is not as hot, air changes loose less heat, so it saves energy by using quartz lights in doors.

The problem is when you only want light, there is no way to stop having heat as well, so with a modern house we use programmable wall thermostats and TRV heads and LED lighting, you can debate which is best method, as it takes longer to heat air than to use radiant heat so then you get geofencing and occupancy detection controlling the heating, so it gets warm before you use the room, which the lighting did not require, however also LED lights tend to last longer as well, so they get rid of the chore of changing light bulbs.

In the main 12 volt lights were used as the filament was thicker and so lights lasted longer, however rather defeats the whole idea if a dimmer switch is fitted, and in the main LED lights there is no advantage using extra low voltage (12 volt), low voltage (230 volt) is simpler and easier. So now may be the time to consider moving to LED, and swap G5.3 to GU10 lamps, they are still MR16 size, but 230 volt. Note MR16 refers to having a multifaceted reflector 16/8th inch across, it does not refer to voltage or bulb base. Since LED lamps often have no reflector non are really MR16 they are just compatible. Also you can't get LED lamps with G5.3 base at 20 watt, and in the main they are 50 Hz rated, so you can't swap without also changing or getting rid of the power supplies (electronic transformers) you have.

The electrical lighting trade seems to have a problem with definitions and names, when ever a new produce is released, instead of giving it a new name, they add the word "electronic" to old name, and also have big writing on packet saying 50 watt with much smaller writing saying "equivalent to" and the lamp is really 7 watt, and replacing standard tungsten with quartz without saying not suitable for dimming, so it is like a mine field trying to work out what will work with what.

I have nearly swapped all tungsten for LED because don't like changing bulbs every couple of weeks, had one bad tube with LED when it only lasted 18 months but other than toys not had to date a LED bulb fail, and I use cheap B&M and Lidi bulbs. Think about it before spending out more money, is it time to change?

vaughan198 · Post by **vaughan198** » Sat May 02, 2020 11:19 am

Thank you so much for your very conclusive response and thank you @someone_else for trying to triage the situation. It was a loose wire in the first choc box closest to the switch. I guess all the other bulbs must be fed off that one (had two cables).
Now that everything is working Im keen to switch to LEDs.

Can someone recommend the best was of doing that?

From my understanding it seems like I need to remove all the transformers, buy GU10 lamp holders (connect them directly to the mains/choc box) and dimmable GU10 LEB bulbs (will they fit in my existing light fittings)?
Do I need to change the switch?

Thanks so much. As you said it is such a minefield out there!

vaughan198 · Post by **vaughan198** » Sat May 02, 2020 11:52 am

There is talk out there of LED drivers/transformers as well? So confused!

Someone-Else · Post by **Someone-Else** » Sat May 02, 2020 11:57 am

The lamps you currently have are MR16, to change to GU10 you need to change the lamp holder and its support, you would be better off (Cheaper) changing the whole fitting.
Yes get dimable GU10 lamps

The "problem" with dimming an LED is most dimmer switches cant dim them properly (But then again it may be the lamp, I am not 100% sure) My point being that most dimmers will only dim an LED down to around 50% but unlike a "Normal" lamp, an LED will stay the same colour as it dims, "Normal lamps" change to am orangey colour the more they dim (Its the filament it was white hot not just above red hot) Nothing wrong with that, just saying it's not the same effect with LEDs

vaughan198 · Post by **vaughan198** » Sat May 02, 2020 12:08 pm

Thanks. Do you mean something like this?
https://www.screwfix.com/p/luceco-gu10- ... tid=516410

And this would just connect direct to the mains.

Would my current dimmer switch (that worked with the transformers and halogens)? Appreciated your view on LED dimmers.

Thanks,
Will

ericmark · Post by **ericmark** » Sat May 02, 2020 1:58 pm

You should not have dimming switches with quartz lamps, the whole idea of the electronic transformer is to stabilise the voltage as too high and filament melts and too low and tungsten is deposited on the quartz, so the electronic transformer stabilises the voltage better than wire wound 50 Hz so the bulbs last longer, most the LED M5.3 lamps are 50 Hz and need a toroidal transformer, but the inrush for a toroidal transformer means normally you can't use a dimmer switch, so you will need either DC or move to low voltage (230 volt AC) instead of extra low voltage. In the main DC lamps have a built in driver, and can run on 10 to 30 volt with same output, so any variation in power supply output is auto corrected.

As to 230 volt the main way of controlling the current is a capacitor and again this can upset and dimmer switch, be it leading or lagging so often it ends up with the lamp flickering as the electronic switch and electronic items inside the lamp react with each other.

So only sure way to dim is to use same make of dimmer and lamp, so if you look at Megaman as an example they do a list of bulbs that will work this means using well known manufacturers, and in the main this means expensive bulbs and dimming switches, so non dimming GU10 less than £2 each, dimming start at double the price, and your still crossing your fingers.

vaughan198 · Post by **vaughan198** » Sat May 02, 2020 6:02 pm

Thanks for all your tips. I have changed over one circuit to LEDs by removing the transformers and plugging in a GU10 fitting. I have put in Phillips Dimmable LEDs (3.8W=50W 345 Lumens). The bulbs all work but now they dont dim when they used to when they were hallogens.
Is this an issue with the switch? Or do I need LED drivers to dim them?
Its quite an old switch (with three dimmers on it).
Do I need a leading edge dimmer?
Something like this?
https://www.amazon.co.uk/Varilight-Clas ... 136&sr=1-5

Thanks