LED TOPICS

General Information on relevant features of LED luminaires.

Subject Explanation

Lifetime LED luminaires (L70) For all luminaires, normal lighting is indicated:

– The average life span (IEC 62.717) LxB50 at Take 25 degrees. Lx can vary from 70 to 90 depending on the product and the corresponding life span up to 100,000 hours .- Light source lumen maintenance factor (LLMF) 50,000 hours, B50, Take 25º. This is a factor from 0 to 1.0. For industrial fittings, please state:
– The average life span (IEC 62.717) LxB50 at maximum Ta. Lx can vary from 70 to 90 depending on the product and the corresponding lifespan goes up to 100,000 hours.
Lifetime LED driver / power supply The life of LED drivers in our luminaires is typically at least 50,000 hours at maximum specified. Take value, at least 25 °. Normal error rate is maximum 10%. Special drivers have a lifespan of up to 100,000 hours at maximum specified take value.

LED lifetime documentation

Lifetime of module and driver is documented by measuring the components Tc point temperature (Tc point is a specific point on the component) and compares with the component’s maximum set Ta value.

All tests, measurements and certification are carried out at recognized European laboratories and certification institutes

What is Ta Value

The luminaires are tested and approved to ambient temperature (Ta) of 25 °, unless otherwise stated.
What if one of the LEDs on the LED module does not work anymore? A standard method is that a single fault on an LED module that contains multiple diodes will result in a short circuit instead of an open circuit. The short circuit will ensure that the current is passed through the module and that the remaining diodes will continue to work.

What is the lumen of LED luminaires?

We indicate the actual light output or “lumen output” on all our LED luminaires. Display and lamp design directly affect the net effect.

What is the variation in lumen across modules / luminaires (within the same LED generation)?

The variation in lumen on different luminaires is typically +/- 10%. This means that the lightning from a luminaire is stable, but will vary slightly between many luminaires.

What is the color temperature?

Color temperature measured in Kelvin.

What is color tolerance?

The color tolerance of luminaires is expressed in MacAdam steps. The more steps, the higher the tolerance. You can find an explanation of this in our LED section on our website. Most luminaires have an initial tolerance of 3 MacAdam steps. It equals +/- 100K at 3000 Kelvin, but this tolerance rises at higher color temperatures.

What is color stability over life?

A slight change in color can be experienced over time due to changes in the LED. [The change is usually not visible, but may in some cases lead to a higher MacAdam tolerance, for example. 4 steps instead of 3 steps.

What is Ra value?

Ra value is in most luminaires 80. Some products may have another Ra value (eg Ra 90).

Does Ra value change over life?

The Ra value for is usually set with a minimum value, ie. that the Ra value will never come below the stated Ra value over the life of the luminaire.

What is the chemical compatibility (corrosion resistance) of the LED module?

Certain types of LED packages tend to break down from chemical substances such as fluroids, sulfur oxide and others.

In the presence of such gases, particular attention should be paid to the selection of LED types.

In addition to standard specifications, Tecvision can design and produce exactly the specifications where mats are needed.

 

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