How Can They Offer A 10-Year Warranty?
written by August Kruesi
Chief Technology Officer, Big Shine LED
How Can They Offer a 10 Year Warranty?
When we examine the state-of-the-art components in LED lighting, we learn that the electronic driver is the primary sub-assembly that typically fails. Inexpensive drivers may fail in two or three years—even less if the building has voltage fluctuations or adverse conditions. Except for specialized drivers, the vast majority of industry standard drivers are warranted by their manufacturers for either three or five years—seven years with a few selected models. But, it’s becoming common to see LED lighting for sale claiming a “10-year warranty. This makes me wonder, “How can companies offer a warranty beyond the natural life of the product?”
What Does Limited Really Mean?
The answer becomes apparent when we carefully read the actual warranty documents. Every warranty is “limited.” There are always restrictions, conditions, and exclusions. A buyer can never really understand the warranty just from the advertised term. It’s important to read the fine print.
In reviewing a cross section of warranties from major lighting suppliers, we see that many 10-year warranties include a limit on the operating hours. For example, one 5-year warranty limits it to a total of 22,000 hours of usage—this is only 2-1/2 years if the lights are operating around the clock. Another warranty, boasting of a 10-year term, limits use to only 4,000 hours a year. This is less than a 5-year warranty that has unrestricted hours. Even if you can live with this restriction, can you prove it when it’s time to replace fixtures under the warranty?
I also came across a 10-year warranty that only applies to the LED fixture—the driver is covered by a separate warranty. And the driver warranty is only five years. Some LED fixture warranty terms begin with the date of purchase, while others start from the date of manufacture. In other words, the clock was already running for months, maybe even years, before you purchased your fixtures.
Why Don’t Drivers Last for Ten Years or More?
Every driver circuit requires capacitors. The aluminum electrolytic capacitor is used everywhere in such applications because it is very effective (Figure 1). However, capacitors may have latent defects that don’t show up when the capacitors are first installed and tested. Their electrical performance will look the same but later, as the capacitor is stressed by ripple currents, overvoltage spikes, vibration, an increasing number of charge/discharge cycles and temperature swings, the capacitor will begin to break down and fail. Internal shorts may develop, the electrolyte can leak or slowly evaporate, and eventually, the driver will no longer be able to power the LED chips. Of course, a non-electrolytic capacitor can also be used, but the cost is much higher.
Figure 1. The Typical and Widely-Used Electrolytic Capacitor
Even if a capacitor does not have any defects when manufactured, its life is strongly affected by high temperatures. In general, the life of the capacitor will be cut in half for every 10° C increase in temperature. As a result, the manufacturers of LED drivers impose strict limits on the maximum case temperature; if the specified temperature is exceeded, even once, the driver manufacturer’s warranty is void. If we review the specifications for the leading manufacturers and impose a typical delta T vs. the maximum driver case temperature, the environment restrictions become very evident (Figure 2). It is not uncommon for ceiling temperatures to approach 45° or 50° C (113° or 122° F) and even higher in many commercial and industrial buildings during summer months. LED fixture manufacturers pass on this same restriction to the end user in the form of operating temperature and/or cumulative operating hours restrictions.
There is a second approach that some fixture manufacturers are taking. In order to offer the 10-year warranty, some are, in effect, offering a service warranty. Anticipating a certain failure rate for the driver, additional cost is added to the product to enable driver replacement down the road. This requires a careful balance between the grade of driver built into the fixture and the projected failure rate. Every driver has different characteristics and performance, so it will be wise for the user to select a lighting manufacturer that understands the technical issues well and is honest and open about the limitations of technology.
Figure 2. Lighting Fixture Operating Temperature Restrictions Implied by Driver Manufacturer’s Maximum Case Temperature Limits
Unfortunately, many lighting companies are using the LED lighting 10-year warranty as an advertising gimmick. They know the 10-year warranty will grab your attention. However, this catch phrase becomes very deceptive when they bury exclusions and limitations in the fine print. Table 1. below highlights just a few of the differences.
The process of filing a warranty claim can also be arduous and require you to remove fixtures that have failed, ship them back to the manufacturer, and then wait, possibly for a number of weeks, while the manufacturer examines each failed fixture and determines it to be faulty. In the meantime, your building is missing a number of lighting fixtures, or you extend the aggravation by only sending back a few fixtures at a time.
Big Shine LED doesn’t believe in playing the warranty game. We offer you a solid 5-year warranty, backed by a BBB A+ rating, and a commitment to provide excellent customer service. Our customers refer new business to us because we honor all of our promises.
Table 1. 10-Year Warranties have become a sales gimmick. Please compare for yourself.
Big Shine Also Offers You a Seven- or Ten-Year Extended Warranty
Big Shine recognizes that many purchasing decisions are made based on the excitement of a 7- or 10-year warranty. We don’t want to lose your business, nor do we want to see you miserable in a few years, trapped by warranty exclusions. We can offer you an extended warranty, following the service warranty model, and will do so without the fine print restrictions that other companies are using. We want you to always be our satisfied customer. If this is of interest to you, we invite you to contact us to learn more about this option.
About the Author: August Kruesi, Big Shine LED Chief Technology Officer
August Kruesi‘s career spans 40 years in renewable energy, aerospace, medical devices, and advanced composites. Mr. Kruesi holds U.S. and international patents. He earned a B.S. in Mechanical Engineering, M.S. in Integrative Health Science and Black Belt Certification in Design for Six Sigma (DFSS). He is Instructor Emeritus for his class, Research Methods in Integrative Medicine. Lighting is not new to Kruesi, great-grandson of John Kruesi—a Swiss-born scientist and Thomas Edison’s “right-hand man,” who worked on all of Edison’s most important developments, including the electric light bulb.
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