LED shop lighting -- basic guidance?

[james_s]

I think 12,000 cycles is more than adequate for anything other than perhaps an animated sign or scrolling marquee, that's probably greater than an order of magnitude more cycles than a typical CFL can tolerate. CFLs gained such a bad reputation so the early LED bulbs were over-engineered, manufactures knew that they weren't going to be able to sell expensive bulbs if they didn't live up to the claims this time around. It's pretty nice, I have not had to change a light bulb in 3 years. I've never been able to say that before. In fact the one new "problem" that I have is that I occasionally have to remove a bulb to clean the dust off it.

[Kjelt]

The first cfl bulb called the yelly jar from the 80s had an average lifespan > 20 years, it had an copperiron ballast

[rrinker]

I'm giving up on LED lighting (at least for now).  The 20year bulbs at the home warehouse stores die in about a year, or about 20% of mine did.  Just installed a high output florescent fixture 4 x 50w tubes and I'm very happy with it.  200w ~20000 lumens.  I wired it to be able to only use half the tubes if need be.  Two tubes are still bright enough for almost everything I need to work on.

Interesting, as I've replaced pretty much every ligth bulb in my house with an LED one, usually the Utilitech ones from Lowes, not the fancy name ones. I even have some that specifically say not to use in enclosed fixtures in my enclosed fixtures int eh kitchen - for 2 1/2 years now. Not one has failed. I gave up on the can that was at the landing for the basement stairs - every CFL I put in there died in a month. I finally got an LED replacement one - been there for a year now, still works even when SOME people in my house leave the dang thing on 24/7. Even my backyard floods I replaced with LEDs, 4x 150 watt incandescents replaced with LEDs that in total are less than 100 watts.

 The garage lighting I really need to replace with the tube replacements, but I often don't use the lights out there. I am redoing the basement to accommodate my model railroad, which will use the LED strips to light Room lighting will be a few 2x4 fixtures int eh drop ceiling with either LED tube replacements or panels, but they will only be used during construction and so forth. The train layout will have 2 decks, each deck lit by multiple LED strips. The ones I installed on my electronics bench are super bright, but too bluish, but the same ones are available in a warm white color. I have another reel I got cheap on Amazon to mess around with. Based on the brightness, I figure 2 rows of the white plus a row of RGB (use to do a reddish dawn/dusk transition as well as blue for night effects. One thing I need to do is build some controllers for dimming - I need far too many strings to run it all from one power supply. Won;t be too difficult, Arduino using PWM driving some power MOSFETs, I'm thinking some low power RF to link the master to each slave controller to dim the white and control the color of the RGB. The RGB reel I have comes with a controller than can feed multiple downstream slave controllers but talk about Wun Hung Lo quality products... plus it only does 16 steps per color, so the range of colors is very limited. With 255 steps per color it should eb able to make a much nicer range of colors. Mostly just thought experiments for now but once I finish a few other projects I plan to order some parts and mock some of this up to see how well it works in practice.

[james_s]

The first cfl bulb called the yelly jar from the 80s had an average lifespan > 20 years, it had an copperiron ballast

The Philips SL, I had one of those a Philips rep gave me when I was about 5 years old and my dad took me to a lighting industry convention. Choke ballast with preheat start, that's about as gentle on the cathodes as it gets. They were not very efficient by modern standards though, and they had rather lousy color rendition, and they were bulky and heavy, but they were quite revolutionary at the time.

[CatalinaWOW]

Led bulbs also have a limited amount of soso actions.
Good brands put this on the package. Mine says 30000 hrs or 12000 soso actions.

8+years for a light that is turned on and off twice a day.  Sounds fairly good to me.  Also probably conservative (in the sense that it defines that start of the uptick in the failure rate curve with a moderately broad distribution of actual failures) since the power on and off transients shouldn't be nearly as stressing as they are in a CFL.  I suspect the real life limit for LED bulbs is solder fatigue in the joints at the LED chips themselves due to thermal expansion and contraction.  So there will be a real separation between the houses which operate high quality solder lines and those that don't. 

Every CFL failure I have ever had was in the ballast/start electronics, and was much earlier than necessary due to the choices that were made to reduce costs.  I have literally never seen a CFL bulb with the darkening associated with cathode erosion.

[Kjelt]

I personally thought it was the onoff inrush current stress on the capacitor that limited the lifetime but can be mistaken

[james_s]

I had lots of CFLs wear out the cathodes. The ones in my outdoor lights that switch once then run all night would get heavily blackened at the ends. The cathodes got so worn out that they ran hot and melted the plastic the ends of the tube sat in. The whole tube would take on a gray look as the phosphor was so hammered. I had one in the hall light which was typically turned on when I got home and run all evening, it eventually got noticeably dim and the color had become a bit yucky. One night I heard a small crack noise followed by a brief hiss. An autopsy revealed the arc had moved to the cathode support post, melted that and the thermal shock cracked the glass and let air in.

Most of them though failed due to the ballast. I repaired a number of them that popped the capacitor between the cathodes that allows preheating.

[SeanB]

The first cfl bulb called the yelly jar from the 80s had an average lifespan > 20 years, it had an copperiron ballast

The Philips SL, I had one of those a Philips rep gave me when I was about 5 years old and my dad took me to a lighting industry convention. Choke ballast with preheat start, that's about as gentle on the cathodes as it gets. They were not very efficient by modern standards though, and they had rather lousy color rendition, and they were bulky and heavy, but they were quite revolutionary at the time.

Still have a number of CFL adaptors, that are a regular B22 base, but you can fit in any regular PL lamp from 7W to 13W, with integral starter ( thus any 2 pin PL lamp) and it will run them. The lamps typically lasted 5-8 years on 24/7/365, and for those as dusk to dawn use the lamps did over 10 years, though of course I did use decent Osram or Phillips lamps. Those that are off brand do not last long, worst was a emergency relamp ( stock was due in a week, but needed the lamp now) that lasted 3 days before failing.

Now with the LED lamps I have a string of downlighters that used R80 reflectors, and I used to get around a year out of the Phillips R63 lamps I used, but started to use LED A shape lamps instead where they fitted in there. Interesting in that there are still 2 R63 lamps in there doing sterling duty, while there have been 4 LED lamp failures, which is sad considering the lamps have a rated life of 30k hours, but do not seem to be able to reach it based on the early data.

So, changed lamp type, and made a note that Radiant is not a good supplier of ANY lamp, and the fittings are no good either, just that they often are Hobson's choice in a pinch. Now using a cheaper one ( and saw yesterday Osram has one for the same price, just have to see if they are available in the cool white E27 base, and if they fit the downlighters) and have started marking on the base the install date, to get a life term.

Did pull out an old ( circa 1995) CFL adaptor I repaired around 1997 ( when they cost around $30 each, so fixing the stock faults of blown 1N4002 diodes and fusible resistor, yes a 200V rated diode on a 230VAC mains) and which had been sitting in a rarely used foyer since then. Still worked, though of course did take 5 minutes to come to full brightness, and still had the 10W PL lamp from there in it. Replaced with a 60W B22 incandescent, as this likely will last decades.

Funny thing is the metro still will install incandescent lamps in substation rooms and service corridors, where the light might only be turned on once a decade or so, but must work when needed, as CFL and LED lamps are not guaranteed to still work after 10 years sitting baking in the sun every day.

[james_s]

Incandescent lamps do still have a place, at least so long as they are in mass production. If it's only going to be used once in a rare while, the electricity saved by a more efficient source is not outweighed by the higher cost. For a long time, traffic signals retrofitted to LED were done only on the red and green, the amber was left incandescent because it gets so little use in comparison. The new ones are all LED though, the cost has fallen to where it doesn't matter and the same will likely eventually happen with things like the metro lamps you mention.

For 95% of domestic use though it baffles me why so many people still use incandescent bulbs. Sure they're cheap, but unless your power is free you will pay vastly more in electricity to run one than it costs to buy the LED bulb. I haven't used incandescent in my house in 15 years, except for the bulbs in my oven, microwave and a couple of lava lamps. Even my refrigerator has had an LED bulb in it for about 6 years.

[CatalinaWOW]

It is actually fairly recent that a dispassionate analysis left incandescent completely behind.

CFL beat incandescent by analysis, but the real life results had the higher price of the bulbs with much shorter than projected life eat up the power savings.  They had other flaws like lack of dimming and RF noise generation (unless you further killed the economics by buying very high end products).

LED prices have dropped dramatically over the last few years, and they have been out long enough to demonstrate real reliability.  So now they are clearly the answer.  It has only been 2-4 years since the tipping point was reached.  That is a very short time to change peoples minds who have been doing something one way for decades, and have had the last time someone told them to change to something better blow up in their faces.

[james_s]

CFLs certainly did have disadvantages, but for the most part I was still able to apply them well, resulting in significant money saved. Where they really worked well was outdoor lighting that is on a photocell, starts once a day and runs all night, and indoor lighting like my hall light that is typically turned on when I get home and turned off when I go to bed. For more frequently switched applications like bathrooms and bedside lamps incandescent still compared favorably.

LEDs are far superior to both for almost everything. Prices are now down to where the cost is less than incandescent even not factoring in the energy, $5 bulb lasts ~20 times as long as a typical 750 hour incandescent. So far I tend to believe this, having had only one failure and I was abusing that bulb by running it for prolonged periods base-up in a fully enclosed globe despite explicit warning not to do so.

[nfmax]

LEDs still suffer from problems of EMI, though!

While the economics of replacing incandescents with LED are more or less a walkover now, the economics of replacing CFLs with LEDs are definitely not. I've replaced all incandescents except for the outside lights in the wood yard (which are on a PIR switch), and a couple of G9 halogen fittings which cannot accept LED bulbs*. but I'm swapping CFLs out only when they fail, get annoyingly dim, or I get too cross with the sloooow increase in brightness on switch-on.

* Yes, I know you can get G9 LED bulbs. They fit, but are so big they peek out of the top of the shade, and so poorly designed they cook the LEDs - one lasted less than 9 months

[james_s]

True, and some are much noisier than others. I had a couple of older EcoSmart bulbs that would totally swamp some of the bands on my scanner. The Philips and Cree bulbs seem to be reasonably clean but I lack a spectrum analyzer to do a proper test.