Informative notes on luminaire lifetime
v. 2.2
Dear Customers,
we would like to focus your attention on some important issues that help to better understand the difference in meaning of the term “bulb life,” depending on whether it is used in “common jargon” or in the text of legal regulations applicable to commonly used LED bulbs, also referred to as “LED Retrofit.”
In this way you will be able to better delineate your expectations as a consumer and to some extent limit the reasons for “disappointment” when faced with an interruption in operation that is generically blamed on a manufacturing defect but is, in fact, very often related to the product’s reached performance limits.
The lifespan (e.g., 15,000 hours) of a light bulb, a figure listed on the packaging, is therefore not exclusively indicative of the period of illumination you will be able to enjoy. There are other operating parameters, established by regulations, which, intersecting with the “pure duration” of light emission, can determine, in fact, an additional limit to the possibility of using a bulb, that is, shorten its “life.”
For example: the number of ignition cycles allowed before the occurrence of a possible failure can strongly affect this result.
In other words, a light bulb subjected to more switching on and off than intended in the design (and by EU standards) would have every right to cease functioning, even if the light-emitting part, i.e., the actual LED, had not yet reached its end of life.
Experimental tests, supported by surveys of the home habits of us all, confirm, for example, that the “kitchen” is the most “visited” room of all, and therefore, LED lighting equipment, as well as fluorescents and halogens, are subjected to a very high number of cycles, which very often crosses the pure life of the light source, leading on a practical level to its not being fully utilized.
The most recent reference standards consider, for example, the:
Maximum acceptable “premature” failure rate:
- not exceeding 10.0 % after 3,000 hours of operation and 1,200 on-off cycles;
This implies that up to 10 percent of the bulbs produced/part of the group tested could-rightfully-not exceed 3,000 hours of operation.
Definition of “bulb life”
The regulations state that “the life of the bulb” is represented by:
- the number of hours between the start of the use of and the time when for 50 % of the light source population the light output has gradually decreased to a value below 70 % of the initial luminous flux.
Further indexes:
- Lamp survival factor at 3 000 hours: ≥ 0.90
- Luminous flux maintenance:
– at 3,000 hours: ≥ 0.70
– at 15,000 hours: ≥ 0.93
– at 20,000 hours: ≥ 0.95
– at 30,000 hours: ≥ 0.96
– …
This means that:
an amount of up to 10% of the bulbs produced/factoring part of the group tested may not exceed 3,000 hours of use, and that after 3,000 hours of use, an amount of up to 30% of the bulbs produced may no longer emit “light” in the amount originally intended. In other words, while still functioning, it may emit less than the “nominal” amount of light.
The limits set for these parameters, intersecting with each other, thus determine the actual usability of the bulb.
So, all these requirements, although they may sometimes appear contradictory, nevertheless represent the overall average performance level available in the market.
Ultimately, the Legislature intended to establish a threshold of minimum performance that would provide an initial level of certainty for the consumer, anticipating that free competition would then drive manufacturers to offer improved performance that exceeded the minimum performance limits established by regulations.
You now have a clearer idea of what to “expect” from an “LED Retrofit” bulb.
Our designers, along with production facilities, have been guided by design and execution limits that exceed the requirements of regulations. This contributes to a significant possibility of superior enjoyment of the benefits to be demanded by them.
All of the above shows us that product “lifetime” expressed in terms of hours is, therefore, only one of the parameters describing the usability performance of an “LED Retrofit” bulb.
Finally, keep in mind that any industrial product-like all human artifacts-has a “defect rate” anyway.
This rate is still present regardless of the efforts that manufacturers make to contain it as much as possible.
Moreover, in the case of LED Retrofit bulbs, since worldwide production involves several billion pieces annually, it is obvious to all that the “reasons of mathematics” dictate that nonetheless some bulbs will still carry construction defects and that, despite countless checks, some of them will still manage to reach the user.
In such cases, there is room for warranty action against manufacturing defects.
On the packages are the most important information discussed so far.
Your choices can therefore be better guided by knowledge of all these elements.
Finally, please keep in mind that, until proven otherwise, it can never be ruled out a priori that the origin of a malfunction is due to a cause external to the product, and only a “particularly exaggerated” technical analysis, on the product that has stopped working, can confirm the true reason for the malfunction.
In this regard we point out that LEDs, which form the basis of modern Retrofit bulbs, are, by their design and construction nature, highly sensitive to voltage fluctuations and electrostatic discharge, conditions that can also lead to irreparable failure.
The issue related to isolation and transient electrical phenomena is strongly felt, and is the subject of wide discussion, as modern electronic equipment, which now fills our lives, is exposed to the possibility of not withstanding them. For example, it is well known to all that uninterruptible power supplies, which are connected to most of our computers, perform not only the function of “battery back-up,” but also that, no less important, of protecting from these phenomena the equipment to which they are connected.
One of the most effective solutions is to use surge “arresters,” placed upstream of the installation and with proper grounding of the system.
Let us also not forget that all performance obtained during certification, and ultimately offered by mass production, is verified by sophisticated instrumentation and obtained in constant, controlled temperature environments and with the use of stabilized power supplies. All conditions not always found in everyday use
All these phenomena are well known to us and urge us to share in your expectations and your desire not to incur any of these ill-fated events.
Events that, while allowed by the standards, may irritate and create discomfort because they limit the performance expectations of the chosen product.
Warranty interventions all engage in an attempt to limit those inevitable annoyances that the end user must endure in dealing with a case of malfunction due to supposed manufacturing defect.
These interventions thus contribute, together with the continuous work of designers and production, to the constant improvement of the products.
Do you still need help?