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Thread: The hidden, extremely costly LED lighting maintenance

  1. #1
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    The hidden, extremely costly LED lighting maintenance

    LEDs should not be placed into commercial application without specification item "lamp shall not blink upon failure, and failed lamp shall not repeatedly flash upon power up"

    Commonality between LEDs and CFLs: They're both prone to misapplication, because, most of them specifically disapprove enclosed fixtures and enclosed fixtures are far more common than enclosed rated lamps.

    The outcome is the same. Reduced lamp life.


    Commonality between LEDs and some induction: While failing HPS sodium can be annoying, it's tolerable. The most common cause of outage for LED and induction is ballast failure. Unfortunately, not all LED ballast engineers did not incorporate non-blinking fault mode. They can act erratic and blink or strobe for a long time without killing itself within a few days like CFL. They can exhibit temperature dependent failure such as working normally, but blinking at a turn signal pace after a few hours of burning at ambient over 75F. Without specifying a non-blink requirement, failing LED ballast can blink extremely annoying and demand an immediate service call.

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    Quote Originally Posted by Electric-Light View Post
    ..... Without specifying a non-blink requirement, failing LED ballast can blink extremely annoying and demand an immediate service call.
    I love service calls.
    Once in a while you get shown the light
    In the strangest of places if you look at it right. Robert Hunter

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    Is there a question or are we just getting lectured?
    "Electricity is really just organized lightning." George Carlin


    Derek

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    I think its a good lecture, or opportunity to learn from others mistakes.

    If LED retrofits are part of your business, warranty issues happen if temperature limits are not carefully considered.
    Roger Ramjet NoFixNoPay

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    Quote Originally Posted by Electric-Light View Post
    LEDs should not be placed into commercial application without specification item "lamp shall not blink upon failure, and failed lamp shall not repeatedly flash upon power up"
    Only if you insist on that spec for all lamp types.

    (We know you don't like LEDs, there's no need to keep pressing the point.)

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    Quote Originally Posted by zbang View Post
    Only if you insist on that spec for all lamp types.

    (We know you don't like LEDs, there's no need to keep pressing the point.)
    When new solution causes a problem in the field that was not a problem with traditional solutions, adding requirements to everything can complicate things and add up cost. Earlier implementation of electronic ballasts had a problem not being able to tolerate ordinary surge.. and now there are specs in the manufacturing of electronic ballasts pertaining to surge tolerance.

    It would be an unnecessary burden to add these requirements to magnetic HID ballasts or transformers.

    Induction CFL and LED excited solid state fluorescent street lights are the technologies used today that often fail with highly distracting flashing or blinking having a short constant, for an extended period of time due to ballast failure. A malfunctioning traditional technology can cycle, but the time constant is in the order of minutes.

    It takes a several to several tens of times of voltage to engage to start a discharge lamp and the voltage plummets to normal level. There's a huge gap in drop-in and drop-out voltage.

    LED lamp elements also stays non-conductive and suddenly starts letting current when you hit the threshold voltage, but LEDs have almost no such gap in drop-in and drop-out and it's common for failing LED ballast to oscillate somewhere between disco light and turn signal rates. The amount of complaints depends on psychological nuisance factor of the rate and rhythm.

    You can drive your car with one headlight out until you get a chance to fix it. However, if one of the light is flashing like a police car light, you can't drive around like that even for a short period. This could happen if you experience a headlight LED ballast failure if the ballast is not specifically inhibited from failing like this. Failure is a failure that requires a repair, but the impact of failure is dramatically different.

    LED money savings claim absolutely ignore the cost of priority service to deal with blinkers that could have been put aside for routine maintenance. This one call can wipe out many years of savings. Further cost increase is that many LED fixtures are not repairable, so a dead wall pack isn't a re-lamp or a repair. It becomes a permit required fixture change out.

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    Quote Originally Posted by Electric-Light View Post
    When new solution causes a problem in the field that was not a problem with traditional solutions, adding requirements to everything can complicate things and add up cost. Earlier implementation of electronic ballasts had a problem not being able to tolerate ordinary surge.. and now there are specs in the manufacturing of electronic ballasts pertaining to surge tolerance.
    Hmmm..........

    FWIW, and I have made this point before, we have been using LED indicator lamps on drives and controls panels for decades.
    Typically like this:



    The justification wasn't on energy savings. It was reliability. In 25 years I know of not one single failure.
    Si hoc legere scis nimium eruditionis habes.

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    Quote Originally Posted by Besoeker View Post
    Hmmm..........
    FWIW, and I have made this point before
    Yes, you have and it's irrelevant. It's like attesting to the reliability of a cooling fan at the back of a computer that seldom experience motor drive failure in a discussion about a 100 hp system in an industrial plant. Those LEDs are driven at very low power and ballasted passively with a single resistor. Line voltage LED indicator consumes over 95% of milliwatts of power used in the ballast resistor but the total power is so little that it does not have heat dissipation concerns. The power density of lamps you keep talking about is essentially zero.

    Build an A19 bulb using 3 LEDs/juntions in series with a series resistor ballast thermally bonded to the metal body and set the resistor so the whole thing only consumes one watt, and you will enjoy similar durability as the indicator lamps you keep talking about but you have a ballast loss of about 25% operated from a native 12v DC source. This is how 12v rope LEDs are setup. Realistically, ballasting loss is 35-40% since utility to 12v DC power supply is only 80-85% efficient.

    Since common usage demands a drop-in replacement, comparable output, low flicker and have a better than CFL lm/W, the lamp will inevitably rely on transistorized LED ballast which is the weak link that blows up and cause disagreeable behavior as it fails.


    Concerning LED light bulbs, they're often inappropriately used to replace CFLs which are also inappropriately installed in a fixture designed for 40 or 60W A19 lamp. This happens, because enclosed rated lamps are rare. It is because there's a significant technical challenge to building a lamp that can maintain the rated output in this environment and survive the rated life because it is a technical challenge to build an effective electronic ballast (effective means maintain flicker level comparable to incandescent lamp) that can survive this environment to be able to have desirable rated life span. You should have some skepticism on 800 lm LED that says suitable for use in enclosed fixtures as well as being dimmable. Some of them internally use the second 0-10v like input on the ballast tied to a temperature sensor and dim the lamp and support enclosed fixture by dimming the lamp. This meets realistic specs for motion activated security lights when full output for the first five minutes means full output for intended purpose but its not ok for dusk-to-dawn use.

    You have 8-12w (depending on design age and model) going into the size of a baseball for a 60W equivalent, 800 lm lamp. Thermal loading into the body is higher for LEDs than CFL as CFLs can shed quite a bit more of energy as infrared than LED.
    Enclose it within a fixture. The more heat that has to be rejected by conduction means the hotter the lamp body gets.

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    Quote Originally Posted by Electric-Light View Post
    Yes, you have and it's irrelevant. It's like attesting to the reliability of a cooling fan at the back of a computer that seldom experience motor drive failure in a discussion about a 100 hp system in an industrial plant. Those LEDs are driven at very low power and ballasted passively with a single resistor. Line voltage LED indicator consumes over 95% of milliwatts of power used in the ballast resistor but the total power is so little that it does not have heat dissipation concerns. The power density of lamps you keep talking about is essentially zero.
    Most of the lights in our house are LED. Including the kitchen spotlights.
    Admittedly, we have been here just a bit over ten years and not a single LED failure. Maybe we just got lucky.
    Si hoc legere scis nimium eruditionis habes.

  10. #10
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    Quote Originally Posted by jumper View Post
    Is there a question or are we just getting lectured?
    I agree what the point, as my experience is very positive.
    Before we (a city) converted to LED signal heads, I would typically get a call at 2:00 am for a lamp out, call a second person, roll a bucket truck to replace a lamp. With LEDs in place now for 15 - 20 years I may get one call a year to replace a lamp.
    Plus we don't have to do annual lamp changes that take weeks of working nights.
    Energy savings are considerable, take an 8 phase intersection, 4 thru movements and 4 left turns with 165 watt inc lamps, do the math when you convert to a 20 watt head.
    The LED signal displays are very reliable few failures and have at least a 5 year warranty.
    Moderator-Washington State
    Ancora Imparo

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