Author Topic: New LED lights reliability  (Read 14082 times)

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Online Kjelt

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Re: New LED lights reliability
« Reply #25 on: February 06, 2019, 09:31:28 pm »
I must say that from the start I have always thought and believed in led lighting as:
- new designed permanent led fixtures
- low voltage driven (12-39V)
- dedicated drivers

Since 2011 I have tens of such spots in my ceiling, none has failed.

The problems all seem to concentrate on either low priced stuff or replacing old fashioned conventional bulbs with their antique design and fittings. Very dissapointing that the next generation of lighting is being handicapped by 100 years old designs.
 

Offline timelessbeing

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Re: New LED lights reliability
« Reply #26 on: February 06, 2019, 09:44:17 pm »
When the pot burns out or fails, can you replace just the LED element, or do you have to buy a whole new fixture?
 

Online Kjelt

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Re: New LED lights reliability
« Reply #27 on: February 06, 2019, 09:52:23 pm »
What do you mean with "pot" ?  :-//
 

Offline timelessbeing

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Re: New LED lights reliability
« Reply #28 on: February 06, 2019, 10:20:15 pm »
We call them pot lights in North America, because the enclosure looks like an upside-down cooking pot.


 

Offline djacobow

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Re: New LED lights reliability
« Reply #29 on: February 06, 2019, 10:24:23 pm »
The problems all seem to concentrate on either low priced stuff or replacing old fashioned conventional bulbs with their antique design and fittings. Very dissapointing that the next generation of lighting is being handicapped by 100 years old designs.

It is not unreasonable for people to not want to replace their old fixtures, which they like and chose at least partly for aesthetic reasons with new ones just because the technology has changed. I suspect that in the long term, people will make such changes, but in this will be gradual, and people want to use LEDs in the short term. Also, it's not like the LED folks are warning everyone that the bulbs that fit in many old fixtures will basically fail much sooner than an ordinary incandescent.

I don't think the next generation of lighting is handicapped this way, by the way. The hardware stores in my area are stocked with all manner of fixtures that have funky new bases or built-in power supplies and non-changeable LEDs. And in fact, in my state, new construction mandates the use of such fixtures in most areas of the home. But you can hardly blame people for not wanting to replace a fixture with a new one that is essentially non-repairable and with no replaceable parts, especially given the failure rates reported in this thread and others.

Personally, I have not replaced the fixtures in the bedrooms in my house because they are absurdly large and unless I want to get similarly large replacements, I would have to respackle and repaint around the fixture for it to look nice, a job I don't usually feel like doing.
 

Online Kjelt

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Re: New LED lights reliability
« Reply #30 on: February 06, 2019, 10:25:06 pm »
Ah ok, well if the driver fails you can replace it or as we are EEs here repair it  ;)
But indeed when the leds are EOL the entire "pot" will need replacement or again since we are EEs here we could replace the donut (aluminium plate with the leds soldered on them) or replace the leds by physically removing them cleaning the donut and reflow new replacement leds on them.

Since the life expectancy of these "pots" are 25 years with 60-70% of original lumens left and I reprogrammed the driver to output max 80% of the nominal current my guess is that these "pots" will outlive me  :)
 

Offline djacobow

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Re: New LED lights reliability
« Reply #31 on: February 06, 2019, 10:27:20 pm »
We call them pot lights in North America, because the enclosure looks like an upside-down cooking pot.

I also hear them called "cans" a lot.
 

Offline djacobow

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Re: New LED lights reliability
« Reply #32 on: February 06, 2019, 10:31:59 pm »
Ah ok, well if the driver fails you can replace it or as we are EEs here repair it  ;)
But indeed when the leds are EOL the entire "pot" will need replacement or again since we are EEs here we could replace the donut (aluminium plate with the leds soldered on them) or replace the leds by physically removing them cleaning the donut and reflow new replacement leds on them.

Since the life expectancy of these "pots" are 25 years with 60-70% of original lumens left and I reprogrammed the driver to output max 80% of the nominal current my guess is that these "pots" will outlive me  :)

I think you are right, assuming everything goes well. My fear is that many of these will not last 25+ years, but as they say, time will tell. My experience so far is that purpose-designed LED fixtures are working OK after >7 years.

As it happens, I have some CFL-based cans in my kitchen that were mandated by the State of California at the time the kitchen was remodeled. These were designed to take CFLs and have the ballast built in. Out of six lamps, one of the ballasts has already failed, requiring me to go into our gross attic to replace it. I have also replaced at least a dozen CFLs in the last few years. So, once again, painful experience has made many of us rather skeptical.
 

Online Kjelt

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Re: New LED lights reliability
« Reply #33 on: February 06, 2019, 10:40:20 pm »
It is not unreasonable for people to not want to replace their old fixtures, which they like and chose at least partly for aesthetic reasons with new ones just because the technology has changed.
If you have designer fixtures or antiques I can understand and you should preferably continue using the original conventional bulbs since that is where they were designed for.
I must not think of the idea of a led bulb in an original Tiffanies.

But for the rest it is silly esp when you see how easily people buy and throw away their other electronic devices some costing many times more than all the fixtures in the house.
So I claim it is mostly not esthetics, it is lazyness for upgrading esp. when it needs extra work because it does not fit, which is ok but should be named as such.


Quote
Also, it's not like the LED folks are warning everyone that the bulbs that fit in many old fixtures will basically fail much sooner than an ordinary incandescent.

Because it depends on the fixture. If it has enough room or openings to keep the airflow keeping the bulb relative cool there is no problem. However many fixtures are closed at the fitting, and if upside down there is where the heat will be kept, ergo short lifetime. There are gazillions of different fixtures go try to explain to mrs Jones age 75 which fixtures are ok to upgrade and which not.

Quote
But you can hardly blame people for not wanting to replace a fixture with a new one that is essentially non-repairable and with no replaceable parts, especially given the failure rates reported in this thread and others.
If you are over 45 and use the dedicated led fixture for 8 hours a day and turn it down to 75% it will outlive you , perhaps the driver capacitor should be replaced sometime  ;)

Quote
Personally, I have not replaced the fixtures in the bedrooms in my house because they are absurdly large and unless I want to get similarly large replacements, I would have to respackle and repaint around the fixture for it to look nice, a job I don't usually feel like doing.
I mentioned that above, but if it is much work I understand, if it is part of the architecture or you like the esthetic looks I also understand. The price might be to have to replace the bulbs sooner than expected due to lifetime issues.
 

Offline djacobow

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Re: New LED lights reliability
« Reply #34 on: February 07, 2019, 12:32:14 am »
If you are over 45 and use the dedicated led fixture for 8 hours a day and turn it down to 75% it will outlive you , perhaps the driver capacitor should be replaced sometime  ;)

This is not quite right. If the 25 years is a guarantee, then great, when it fails ahead of that, you bring it back and get a new one for free, right? Or maybe for the pro-rata remaining expected lifetime? In reality this will be hard if the store or company is gone.

But the real problem is that often no such warranty is provided. Instead, it is a "claim." Furthermore, it is really a 25 year MTTF, which, depending on the shape of the probability function, means that there is a significant chance of failure after only a few years. And if you have, say 20 of those fixtures and the probability curve is normal around the mean, the chance that one or more of them fail in a few years is actually very high.

I don't dispute the rest of your response. Yeah, it would be hard for manufacturers to advise everyone on whether a bulb would work in a given fixture, but a simple acknowledgement that a bulb *will* fail early if in a fixture without free air flow would be nice.
 

Offline james_s

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Re: New LED lights reliability
« Reply #35 on: February 07, 2019, 01:50:18 am »
I upgraded all the bulbs in my house from CFL to LED starting in early 2011 extending over the next couple years. Initially I was replacing CFLs as they failed but the LEDs were so much nicer that I soon got tired of waiting. I used Philips, EcoSmart (Home Depot brand) and Cree bulbs. Later on I got a few inexpensive GE bulbs. Since then I've had two of the Ecosmart and one GE bulb fail, and the glass bulb fell off a Cree but it still worked. All of the ones I had problems with were in heavily used fully enclosed fixtures despite the bulbs saying not to use them fully enclosed so I consider that my fault. The Philips have been the best, I have yet to see a bad one anywhere.
 

Offline james_s

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Re: New LED lights reliability
« Reply #36 on: February 07, 2019, 01:54:44 am »
If you have designer fixtures or antiques I can understand and you should preferably continue using the original conventional bulbs since that is where they were designed for.
I must not think of the idea of a led bulb in an original Tiffanies.

But for the rest it is silly esp when you see how easily people buy and throw away their other electronic devices some costing many times more than all the fixtures in the house.
So I claim it is mostly not esthetics, it is lazyness for upgrading esp. when it needs extra work because it does not fit, which is ok but should be named as such.


Why does it even matter? It took some work to design a suitable retrofit LED bulb but now that has been accomplished, they are quite good, inexpensive and reliable. There are advantages too, if you want to change the color temperature or wattage or install something different like a colored bulb or blacklight for holidays/events/parties you simply unscrew one bulb and screw in another. You can't do that with fixtures that have built in LED modules.

Those of course have other advantages, they can be made in unique shapes and styles, it's good to have them available too. I like choices.
 

Offline timelessbeing

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Re: New LED lights reliability
« Reply #37 on: February 07, 2019, 02:47:42 am »
the bulbs saying not to use them fully enclosed
ALL bulbs should work enclosed. If it doesn't it's farking useless.
 

Offline djacobow

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Re: New LED lights reliability
« Reply #38 on: February 07, 2019, 04:10:41 am »

Why does it even matter? It took some work to design a suitable retrofit LED bulb but now that has been accomplished, they are quite good, inexpensive and reliable.

Except that bulb has not yet been designed at all.

Ceiling fixtures are a common use case. There are zero bare bulbs or bulbs in table lamps in my home but there are many ceiling fixtures. And these bulbs fail in such fixtures. I have tried many and thrown away a lot of money in the process.

You can define away a problem if it makes you feel better, but if your question is why do people not run out and mass adopt these otherwise wonderful "retrofit" bulbs, the answer is staring right at you.

* PS - in the US, 37% of households are renters. Those folks are not in a position to "just replace the fixtures". They're stuck with what the landlord installed.
 

Offline Psi

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Re: New LED lights reliability
« Reply #39 on: February 07, 2019, 05:09:52 am »
apples and oranges.
Led light strips have a diffused light for coves and large area lighting.
Led spots have a focussed light beam to accentuate certain objects.

Besides the efficiency of led strips is low due to the resistors

i don't mean the OP should use strip lights, just that you need to make your own lights if you want them to still be working 20 years from now.
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Offline timelessbeing

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Re: New LED lights reliability
« Reply #40 on: February 07, 2019, 08:34:43 am »
I felt compelled to tear apart a failed bulb I had (a one-way process unfortunately).

The thermal design actually seems decent to me. Lots of chunky aluminum. But the power supply is really horrid. The board (the crappiest phenolic resin) was scorched black, and on the verge of crumbling apart. The components look really cheap. Protection consists of a resistor.

The LED array looks good too. They used some fancy springy through hole contacts for the connector. The LEDs seem to have gone open circuit unfortunately, so the bulb has pretty much self destructed.

It's kind of a shame because overall the construction seems good, and aluminum is not cheap. And it's all crippled because they tried to save a penny on the driver.
 

Offline OwO

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Re: New LED lights reliability
« Reply #41 on: February 07, 2019, 09:48:59 am »
Doesn't matter how good the thermal conductivity from LED to casing is, it's still crippled by the (nonexistent) surface area of that form factor. You will never be able to dissipate >5W of power in that size while keeping the LEDs adequately cooled without a fan.

The large rectangular ceiling-mount light fixture design gives you both repairability and good cooling. If a LED fails you can either replace the strip (no soldering needed) or if you want, replace the LED.
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Offline OwO

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Re: New LED lights reliability
« Reply #42 on: February 07, 2019, 09:53:36 am »
This is the type I'm talking about:



Inside there are rows of LED strips screwed to the top aluminum panel, which is screwed to the ceiling.
You want to get one with the largest area possible, and space out the LED strips.
« Last Edit: February 07, 2019, 09:55:38 am by OwO »
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Offline Siwastaja

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Re: New LED lights reliability
« Reply #43 on: February 07, 2019, 10:18:45 am »
Doesn't matter how good the thermal conductivity from LED to casing is, it's still crippled by the (nonexistent) surface area of that form factor. You will never be able to dissipate >5W of power in that size while keeping the LEDs adequately cooled without a fan.

Luckily, there's no need to dissipate over 5W in the E27 bulb form factor.

The key to a good design is to use the most efficient LEDs available (the typical variance is around 2x, from around 70 lm/W to about 140 lm/W, so this does matter), combined with an efficient driver. Done this way, a 5W LED bulb emits about 2W of light and heats about 3W, while producing around 500lm, which is what the original fixtures were designed to deliver, and what people expect them to do.
 

Offline Psi

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Re: New LED lights reliability
« Reply #44 on: February 07, 2019, 12:45:23 pm »
I put a thinner version of those square panel lights on top of my motorized drop down projector mount.
Keeps it nice and hidden away :)
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Offline 001

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Re: New LED lights reliability
« Reply #45 on: February 07, 2019, 02:26:09 pm »
Hi!

SMD LEDs are foolish vintage crap.
Try  new  technology https://en.wikipedia.org/wiki/LED_filament
 

https://youtu.be/25j2C4jq2HI
« Last Edit: February 07, 2019, 02:30:20 pm by 001 »
 

Online NiHaoMike

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Re: New LED lights reliability
« Reply #46 on: February 07, 2019, 02:33:48 pm »
* PS - in the US, 37% of households are renters. Those folks are not in a position to "just replace the fixtures". They're stuck with what the landlord installed.
Or bring your own plug in lamps. On a side note, it appears that in Australia, the light fixtures plug in so renters *can* change them as Dave did in his lab.
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Offline james_s

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Re: New LED lights reliability
« Reply #47 on: February 07, 2019, 04:45:08 pm »

Why does it even matter? It took some work to design a suitable retrofit LED bulb but now that has been accomplished, they are quite good, inexpensive and reliable.

Except that bulb has not yet been designed at all.

Ceiling fixtures are a common use case. There are zero bare bulbs or bulbs in table lamps in my home but there are many ceiling fixtures. And these bulbs fail in such fixtures. I have tried many and thrown away a lot of money in the process.

You can define away a problem if it makes you feel better, but if your question is why do people not run out and mass adopt these otherwise wonderful "retrofit" bulbs, the answer is staring right at you.

* PS - in the US, 37% of households are renters. Those folks are not in a position to "just replace the fixtures". They're stuck with what the landlord installed.


That's funny because I have dozens of these bulbs that haven't been designed yet in my house, many of which have been in service since 2011 and they work just fine. A majority of the lights in my house are enclosed ceiling fixtures, I did have a few early LED lamps fail but most have been fine, I've almost forgotten what it's like to change a lightbulb.
 

Offline mikerj

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Re: New LED lights reliability
« Reply #48 on: February 07, 2019, 04:47:52 pm »
Hi!

SMD LEDs are foolish vintage crap.
Try  new  technology https://en.wikipedia.org/wiki/LED_filament
https://youtu.be/25j2C4jq2HI

Perfect if you like really flickery lights that aren't compatible with dimmers.
 

Offline 001

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Re: New LED lights reliability
« Reply #49 on: February 07, 2019, 05:06:34 pm »
Perfect if you like really flickery lights that aren't compatible with dimmers.

I cant see any flicker on it with my phone (but phone can help to see fliker at notebook screen)
 


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