How is the MTBF rating for the led highbay fixture? · MTBF and qualified for you or not. OK LED...

OK LED Lighting Limited Shenzhen, China [email protected] +86-755-27381641 www.okled.com

How is the MTBF rating for the led highbay fixture?

Mean time between failure(MTBF) means the average time between failures of the led highbay fixture. To answer this question we need to know what are the critical parts for the LED lights.

The critical parts for the LED lights.

1) The LED driver.

2) LED chip

The other parts are plastic or aluminum, which I think it will not fail in a short time or never fail.

What the main component for this led highbay fixture used?

So if we could know what this led highbay fixture main components. The MTBF risk will be much lower. This HiCloud LED HighBay Fixture use Meanwell brand driver, and Nichia LED.

mailto:[email protected]

http://www.okled.com/?from=faq-mtbf-foot


When we open remove the driver from the fixture, we could find out this label behind the driver. This label will tell you what kind of driver it is. What's the IP Rating, certificate, voltage and current issue. HiCloud LED HighBay Fixture driver lists: 100W 120W and 150W HiCloud HB use the same item of driver which is HBG-160-48A. 200W HiCloud High Bay use this item driver HBG-240-48A The LED is very small component. There is no any label on the LED chip. But we can let you know that we use original Nichia LED chips imported from Japan directly.

Find the spec of the High Bay driver.

We could download these driver information from these links: http://www.meanwell.com/search/HBG-160/default.htm http://www.meanwell.com/search/HBG-240/default.htm When we click the above links, we will see that we could find out the spec, report, certificate etc documents.



http://www.meanwell.com/search/HBG-160/default.htm



HiCloud High Bay MAX wattage range is 200W. So Let's check the 200W HiCloud Highbay fixture driver spec. 1) We're glad to see that the driver features words shows that Meanwell offer a five years warranty. And 40000 hrs @ Tc 70℃ guarantee. Tc means Tcase, which is the driver housing case temperature. This data is very important it means that if the original driver manufacturer could give OK LED a five years warranty. OK LED will not have excuse or pressure to give end user a five years warranty. 2) HBG-240-48A driver efficiency is 93%. So the 200W HiCloud High Bay driver real output power is 200W X 0.93 = 186W And the HBG-240-48A driver output rated power is 240W. So the 200W High Bay driver only




working at load of 186W / 240W = 77.5 % 3) On the spec it shows the working temperature range for this driver is from -40 to 70℃ ambient temperature. I think everyone knows that if the LED driver continuously working at 70℃ ambient temperature for 24hrs a day will sure affect the lifespan. But we get to know that 70℃ is ambient different with Tc. Do you still remember that Meanwell write on the spec feature that it could work at least 40000hrs @ Tc of 70℃? Tc is the driver housing temperature not driver ambient. To find out the real data, we could read this file: http://www.meanwell.com/search/HBG-240/default.htm This above file include the reliability test result as below:

If anybody has electronics background, he will know that the capacitor part is the shortest lifespan part in the driver. Meanwell should use very high quality capacitor, it shows that if the driver working at 75% load, it could last more than 60000 hrs, @ 60℃ Ta. HiCloud 200W high bay works at 77.5% load. Meanwell have finished the DMTF accelerated life test, this driver at least cloud last 40000 hrs @ Tc 70℃. Right now, the only issue is to find out what's the Tc for HiCloud 200W High Bay fixture driver. Let's hand on this topic and see some information about the LED chip.

Find out the spec about HiCloud LED High Bay fixture LED chip.

As soon as we open http://www.nichia.com. We will be redirect Nichia homepage.




http://www.nichia.com/


Nichia put 757D series on the first banner of the website. It means that this LED chip is their main product, both of quality and performance. And everything should be good or it will not put it to top of their website. Of course, the fastest way to know the LED chip good or not is to ask if it has 10000hrs LM80 test report or not. LM80 is DOE approved method for measuring lumen depreciation of solid-state (LED) light source. If your supplier cannot provide you LM80, don't believe it will have more than 50000 hrs lifespan or even 30,000 hrs lifespan. The below picture is cut from the LED chip used in HiCloud High Bays 10000hrs LM80 test report.

Case temperature or Ts means the temperature at the LED chip soldering point. TM-21 projection(10K) means that this LED chip just finished 10K hours testing and it's proved to last longer than 60K hours at certain temperature and certain current. And when if it finished 16K hours testing in near future, the data would be updated to about 90K hrs L70 lifespan.




We could also download its spec. And see the features for this LED chip.

What cares about most should be the forward current, and Junction Temperature. We have to find out what the HiCloud High Bay uses. HiCloud High Bay 100W 120W 150W & 200W uses the same die casting aluminum heat sink. So if the 200W don't have temperature issue, the other item should not have. So clients should care about the 200W most.

The 200W HiCloud High Bay uses 252 LEDs. Based on calculation, we could know that its driving current is about 120mA, it is still far away from the max driving current 200mA. If the driving current don't have issue, what we need to care about most should be the thermal management. The below picture is quotes from Nichia LED specification.




Nichia tell us that LED die temperature is affected by PCB thermal resistance and spacing on the board. Comparing with competitors, we are much better at this. Our board size is 234mm, each LED has may be 1cm spacing

While our competitors only use this such small size COB LED chips, each LED may be less than 1mm spacing.

So LED spacing is not an issue for HiCloud High Bay. The next thing is Tj = LED chip soldering point temperature + resistance temperature. The resistance temperature = LED wattage X LED Thermal Resistance = 120mA x 6.4V X 11 = 8.5℃ So the next factor is the LED chip soldering point temperature Ts. Plus the driver case temperature Tc. If you get both of these two factor from us. you will know whether our products MTBF and qualified for you or not.




To know the real temperature of HiCloud LED Highbay Fixture.

Most of un-qualified factories temperature test is based on around 25℃. I don't think it's fair for our dear clients. As we all know, the high bays are often installed near the metal roof where is very hot in summer. So we tried to test the data as real as possible. So we test the fixture as high as @ 45℃ ambient temperature and running after 4 hours.

Do you see that, we put the sensor inside of the lens. Because we sell the lights with IP65 rating, we want to test the data as accurate as possible. Lots of suppliers may remove their high bay lens to test the temperature, which I think is accurate at all. Because the air can cool down the LED chip temperature. And we test the LED temperature at the hottest soldering point Sorry, to know the final temperature answer, you need to contact [email protected] Or visit http://www.okled.com to contact our sales people.



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How is the MTBF rating for the led highbay fixture? · MTBF and qualified for you or not. OK LED...

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