Hi, Hope someone can help me out. I had 9No, 50w downlights (all on their own transformers) installed in our kitchen about 2 years ago by a qualified sparkly. From the begining I had problems with them in that they kept on failing one at a time. I managed to repair these without getting a pro in and managed to establish the failure down to various reasons ranging from lamp holders (loose/disconnected cables) to transformers. The problem has recently intensified and now I have 4 out out action. If this carries on, we will have no light at all. Can anyone suggest what might be the problem? These downlights are on the same circuit as the 1st floor lights (where there are a further 11No 50w and 4No 20w downlights but these work fine) and supply power to 2No. bathroom fans, 4no pendant lights and 3no external lights. Thanks in advance
Is it the lamps that are failing or the transformers? Some transformers seem more reliable than others and it may be that they are running too hot, first floor lamps tend to have transformers in a relatively well ventilated attic as opposed to ground floor ones which often get stuffed between floor and ceiling.
which often get stuffed between floor and ceiling. Thanks Oliver1234, The lamps are fine - I've taken these out and plugged it in elsewhere and they work. The kitchen downlights are in a ground floor extension with a flat roof. There is insulation and virtually no ventilation. Would changing the whole fitting with a better make such as Halolite make any difference? Could it also be that there is too much load on the circuit?
circuit? The circuit loading is pretty irrelevant really, from my understanding of your post each lamp has it's own transformer, if the secondary of the transformer were excessively loaded then yes that could be an issue but loading on the mains side won't make a difference to transformer life. The lamps and the transformers should be well ventilated and should not have insulation anywhere near them. Many sparks are reluctant to fit recessed halogen lamps because the generated heat can be dangerous.
The sparky that did ours weren't to bothered where he put them. It sounds as though the lack of ventilation and the relaiability of the transformer could be the cause of the problem.
It sounds as though the lack of ventilation and the relaiability of the transformer could be the cause of the problem. ------------------------------------------------ If it's practical, then change the lamps to 35W... (I assume these are not on a dimmer?)
get yourself a stick and poke it through the downlight hole to push the insulation away from the fitting and the transformer.
lights? The space in the ceiling is about 160mm. The light itself is 110mm so if the lights were in it's place, there would be a 50mm gap. I have also check that only part of the roof (the new extension) has insulation. 2 downlights have gone in the uninsulated roof. I am again at a lost.
the transformers are getting too hot and burning out simple. I have one in my hallway where the transformer is close to some insulation and it goes on and off every 10secs if its on full without no dimming as this is the thermal overload on the transformer kicking in and out.
I agree with foo These lights and their associated transformers absolutely must have sufficient ventilation to dissipate the heat generated. It is obvious from reading your post that in your case the ventilation is totally inadequate which has caused you all the hassle of failed fittings and transformers. That is the root cause. You need to find a way of getting the insulation well away from all of your lights and txs to solve the problem.
I have one in my hallway where the transformer is close to some insulation and it goes on and off every 10secs if its on full without no dimming as this is the thermal overload on the transformer kicking in and out. Sheesh... You'd better get a sparky in to sort that out Foo!!
I dealt with a similar problem for a customer I replaced all the lamps with 35w aluminium reflector or coolfit lamps. The heat from these lamps is reflected through the front of the lamp little heat is produced at the back unlike standard dichroic, which are designed for display purposes where it is preferable for the heat to be dissipated at the back of the lamp.
Thank's everyone. Some very useful suggestions. - - - - - - - - - - - - - - - - - - - - - - - - What about this one - Throw em out fill holes and fit something decent and energy efficient. P.S insulate the flat roof properly and save £££££££££s
I have a similar problem, and with 3 out of 10 downlights actually working and Christmas fast approaching, I've been instructed by swmbo to get it sorted... They've been failing over a long period, rather than going down like dominoes. 1st the bulbs failed fairly regularly, then 1 by 1 the transformers started to go. They're installed in a false ceiling, with 32cm gap to the real ceiling and no insulation, so wouldn't think they could get too hot up there. However, my supply voltage is on the high side - measured at 252V which is almost as high as it can be. According to Osram a 10% overvoltage can reduce halogen bulb life by 75%, so wondering if the high voltage can reduce the life of the transformer as well? I expect the transformer is outputting a correspondingly high voltage, but can't check as my multimeter evidently does not have sufficient bandwidth to measure the high frequency output correctly. I don't want to just swap in new transformers if the root cause is elsewhere, but don't know if there is anything I can do about the high supply voltage 'cos at the end of the day it is (just) within the allowable tolerance. Any advice would be much appreciated. By the way the installed transformer is a Lytlec (now Robus) LEB60D - no idea if this is seen as a reliable make or not. Gez
I can't tell you whether or not your transformers are outputting a higher than normal voltage because I belive some electronic transformers regulate the output irrespective of the input. I can however say that any increase in input voltage will lead to a higher currrent consumption and hence more heat will be generated (somewhere). Have you tried measuring the output voltage with a load in place (good lamp)?
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