LED and overheating

Singapore 21st September 2011

Learning something new about LED’s every day it seems! While it is nice from public relations point of view to have a 100% LED project with a short ROI (Return on Investment), we keep having little problems with the place in full operation for a couple of months now. First we had some humming issues in the decorative pendants, now we have some of the LED down lights flickering and going on and off impromptu without any clear indication why…

I have to state that we did our due diligence before specifying the down lights, LED source and dimming system. Considering we are using the latest 10W Philips MR16 Master LED, we had the luminaire manufacturer test the combination of LED lamp, transformer and luminaire before confirming the specifications to make sure it was all working well together. We then had the whole system tested (including the recommended transformer) with the proposed dimming system. All came back positive so we went ahead with the installation. Now after a few months operation we start having some issues with LED down lights flickering and going on-off.

We investigated the situation and narrowed down the probable causes. As not all LED donwlights in the same circuit are affected with the “symptoms, we can say that the dimmer is not at fault. This narrowed down the probable causes to either the lamp itself (it is a new lamp), the way it is connected in the lamp holder or the transformer. However after talking to Philips a new possiblity came up…over heating! The LED lamps have a built in “thermostat” regulating the lamp if it gets too hot. Philips is now saying this affects the lamp performance and issues like flickering or going off can occur. Apparently this seems to happen a frequently in new installations but was not brought up during testing by Philips. It seems now a consistent issue with these lamps…Tomorrow we we will meet to see if indeed this could be the fault causing our flickering and going off problems…

In Light Watch today some mega LED lighting point installations realised (mostly by artists Leo Villareal, Erwin Redl, Jenny Holtzer) to contrast with the relative simple issue I am facing with just a few down lights. Imagine having to fault find in installation with more than 40,000 point like the underground tunnel from Villareal. Pictures from Google.

Light Watch 167: LED installations from Leo Villareal, Erwin Redl, Toshiba and Jenny Holtzer

21. September 2011 by Martin Klaasen
Categories: light watch, lighting applications, lighting of the future | 26 comments

Comments (26)

  1. Martin, we have experienced something similar with newly fitted lights when we originally had halogen lamps.

    We were advised by a lighting shop that the new LED bulbs would give a very good light and last a long time (guaranteed for 3 years).

    However, having very recently changed to LED bulbs, we are now getting the same problem of them going off and on.

    I wonder if this will affect the life of the bulbs and if the guarantee will still stand?

    I note your blog was dated September last year and wonder if there is an update?

    Look forward to hearing from you.

  2. Dear Ann
    I have received many enquiries of the same nature with people experiencing similar problems. It seems to be a common problem that many people face in the retrofit market. I don’t know the environment and the lighting system that ths has happened in and what brand of LED lamps you are using. Heat is one of the key issues with LED lamps. Unknown to many in the general public about 75% of the lamps energy prodution is heat, compared to only 10-20% for halogen lamps. So cooling of the LED lamps is crucial for it to work well and overheating will generally cause the flickering or on-off effects. Some LED lamps have a build in fan and when this stops working it triggers a switch off when the heat limit is reached. Some lights need proper airspace to allow the lamp colling to be effective. Retro fit LED lamps placed in a very enclosed housing may encounter this situation. It is hard for me to say whether you can claim on the warranty without knowing the specific details and warranty conditions but there are certainly cases were the manufacturer should take responsibility and replace the lamps free of charge. I would certainly contact the vendor to establish the root cause of your situation. Hope this helps 🙂

  3. i am doing tests with LED beads.LED with 200 batteries were charged with solar we did not have much sunlight for the past 3 days, I charged it with normal power.from then I see the LED started flickering after working for approx 3 min.I found the back of the LED was getting very hot.I added a small heat zinc to it.the LED started flickering after 8 minutes.when charging on solar the batteries got charged till 3.85v.when charged with normal power the battery charged to to conclude higher voltage caused the LED to over heat,and then it starts flickering.the cause of flickering is over heating,which was caused by over voltage.regards

  4. This is really nice information and I really did not knew this can even be possible. No one think on this side.
    Thankyou keep posting good content

  5. Very good blog post.Really thank you! Fantastic. ecdbeeeedbac

  6. Same problem with blinking here. Called philips and the representative said it was a self-protection feature of the bulbs when they get too hot. My canisters as quite well ventilated and it is the application to which the bulb was intended. If they wanted to define this blinking as a “feature” instead of a bug, ihey should have had the full knowledge and consent of the consumer by notating it on the box at the very least. Better yet, it shouldn’t have been sold at all. Blinking bulbs around the facility turn if from a serious place into something more akin to a Disco.

  7. We had a new house built with energy efficiency in mind, which includes LED recessed lighting fixtures. Now, after four months in the house, we are experiencing the flashing/strobe effect with a couple of the “bulbs” in one of our rooms, but not anywhere else. The particular circuit does not have a dimmer and there are only four bulbs operating on it. I find it odd that the lighting worked fine for the first several months and that this issue just appeared. I am going to first try replacing the “bulbs” under warranty through the builder and hope these two are just defective. The brand is Satco, a manufacturer that I am not familiar with….are there any specific manufacturers that are known to have the most reliable products?

  8. Hi Ernst, I have come across many consumers with LED lighting problems like the one you have; flickering. Your situation is not clear as it could be a compatibility problem if you replaced Halogen lights with its LED retrofit. It could also be a heat issue as some LED’s in the market need good ventilation as they do not cool properly due to poor design or enclosure. As far as I am concerned always stick to reliable and well known brands so that you can claim your warranty if they fail unexpectedly, make sure you get at least 3 year minimum unconditional warranty. Its a cowboy world out there in LED land, so make sure you get your lights from reliable and responsible resellers that give you also the after sales service to make things work! Good luck!

  9. great article, im just getting involved with led lighting (better visibility riding motorcycles)…do you have any knowledge as far as which method of “cooling” would be more effective…ive been seeing alot that have fans and some new products from phillips that use a copper braid strip…any input would be greatly appreciated

  10. dear sir
    we have 100 no philips make led 15 watt panel purchase through dalar ladhuram Toisniwal / R santi lal and installation above fixture our Customer M/S H P CL Budge Budge Terminal only for 15 Nos
    panel light are found defective

  11. I replaced MR16 LED bulbs insted of 50watt halogen MR16 bulbs that were there before. They worked fine. The new LED bulbs stay on for maybe 5 minutes then go off 1 at a time. Replaced 4 bulbs they all do the same after a couple of minutes any sugestions ?

  12. I have a chandelier with 40 LED bulbs and it has two circuits on it so 20 or on one line 20 or on the other it been in there for approximately eight months and almost everyone of the LEDs are burned out it does have a glass globe around it but it’s open at the top and at the bottom is this due to overheating

  13. I have the same problem with an LED in my office, I switched every light in my house to LED as a result of all the hype connected to them when they first hit the market. I guess we are learning through experience that all the glitters is not gold. In time time I am sure someone will come up with the answer as they do with all new tech problems, until such time, we are all the victims of a grand money saving? experiment. At least they don’t cost more than a couple of bucks not ten to fifteen as in the outset.

  14. Dear Walter thanks for your observation. I think through blog’s like mine and many other publications at least we can learn from each other. That’s why we share. That is the power of social media. You can share and learn from each other. Thanks for sharing!

  15. I have fitted 20 5watt Phillips led bulbs in a kitchen. There are 2 switches both dimmer managing 10 bulbs each which is the recommended load for the dimmer. After about 2 months 1 bulb went out, if I switched the lights off for about 5mins they would all come back on then the same would bulb would cut out. I switched this bulb with another but the same lamp fitting switched off. I removed the dimmer and swopped with standard on/ off switch same problem. It is now happening with 4 of the lights, it looks like a problem with Phillips bulbs? Overheating?

  16. Very helpful post. Our LED lights intermittently turn off/on at seemingly random times–so annoying! We decided to switch a few of our fixtures from halogen bulbs to LED to see what light tone we like best (in preparation for a new build which I *had* planned on doing in all LED….now I’m not sure!). Anyhow, I’m going to try another brand of LED bulb to see if that resolves the problem, but otherwise I’m wondering if it’s an overheating issue (in which case, I don’t know that there’s a solution).

  17. Hi Alasdair, thanks for sharing. It feels more like over loading rather than over heating. I have also found that many conventional dimmers (contrary to what the lighting manufacturers claim) are not really compatible with the light bulbs. I think that is what your problem is…
    Good luck

  18. Hi Katie, thanks for sharing. Like with Alasdair’s case it is very likely a problem between the compatibility between the lamps and the electrical infra structure. Manufacturers tell you that you can just interchange the existing conventional light bulb with a LED replacement but very often it results in issues as you are experiencing. As you are replacing halogen, you are probably re-using the old halogen transformer and that one is most likely the culprit. Change to use a proper and compatible LED driver and that will most likely solve your problem. All the best

  19. I recently (about a week ago) installed 2 4′ LED tubes to replace fluorescent tubes. They randomly don’t switch on, or cut out after some time, then switch on again after 20-30 mins approx. The ‘cut-out’ process sounds like a heat problem, but why the failure, randomly, to switch on? Also – I assume I’ll have more problems in the summer, when the inside temperature is about 10 degrees higher?

  20. Hi Patrick
    The problems can be due to a host of things. I don’t know the condition of your installation so its hard to pinpoint the cause. Retrofit lights are not always suitable despite claims from manufacturers. However reliable brands should not give you any problems. Assuming you had a proper quality fixture to start with. Perhaps check with your local reseller. All the best.

  21. Hey Patrick,
    In reference to your problem, I have recently replaced over fifty 4′ four-bulb flourescent fixtures in two laundromats that my family owns. The problem I found to be is that no matter whether or not the ballast is listed on the company’s website for the LED replacement bulbs, it is working for me now after I replaced about two dozen ballasts with brand new instant start ballasts. Even though the flourescent bulbs worked fine with these two dozen ballasts, and other fixtures seem to work fine with the new bulbs and same ballasts, I can only conclude that the ballasts that needed to be replaced were allowing too much “juice” to flow through to the LED tubes causing the overheating issue.

  22. I have been tinkering with replacing conventional 12v bulbs in the fixtures of my RV with COB LEDs. They were rated at .9A but I found that to be too much current causing lots of heat. After a while they began to flicker and then they also flickered at a lower current of .5A as well. So I think the excessive heat caused some damage to the LED. I’m going to scale back the current to .4A with some new ones to see if the flicker damage happens again.

  23. Nice information !

  24. Hello
    I have installed led strips behind a mirror in my bathroom. They are cased in with practically no ventilation. They work fine for a couple of minutes but thenbthey start to flash. Coukd it be that the driver is small or because it is iverhaeting? Each of the srips had36 x 4 LEDs (ie each stip has 4 leds next to each ither) I have two such strips. Each strip has two parallel connectors to the LED driver. What shoukd be the wattage of the driver in this case to run bith strips plesase?

  25. Do integrated LED downlights have the same problems with overheating as LED bulbs in traditional downlight cannisters? Had 8 downlights on 2 switches installed about 3 years ago. With 3 of the cannisters have had constant problems with LED bulbs cycling on and off as well as short bulb life. After 1 year discovered that dimmer switches electrician used were not LED compatible and replaced with non-dimmer switches that are LED compatible. Still having problem with overheating in same 3 cannisters. LED bulbs in these three cannisters get noticeably hotter than those in other 5 cannisters. Considering switching to cannisters with integrated LED’s but don’t know if this will solve problem. Also considered reversed polarity as possible culprit on these 3 cannisters but it is my understanding that LEDs don’t function at all if polarity reversed.

  26. Hi, it really comes down to quality. You get what you pay for. Good quality LED’s should not have any issue with overheating unless they are not installed as per manufacturers guidelines. Though COB LED’s are generally more reliable as the complete system and all components have been designed to be matching with each other. This contrary to a retrofit LED that has to somehow be compatible with the existing system it is placed in. There are excellent retrofit LED’s however if the receiving equipment is not compatible the quality becomes irrelevant
    Trust this helps, all the best

Leave a Reply

Required fields are marked *