Maintenance Factor on LED Lighting Calculations and ... · cie 154:2003 aec confidence on led...

Maintenance Factor on LED Lighting Calculations and Lasting Life Standards

Different MF on LED and HID?

6/3/2014

NO! The MF has the same criterias for both technologies

AEC confidence on LED technology

24/02/2012 AEC Illuminazione S.r.l. 3

MF = FMS x LMF x LSF x LLMF

Luminaire Maintenece

Factor optical unit

Lamp Survival Factor

mortality factor of the sources

Lamp Lumen Maintenence

Factor

Surface maintenance

Factor (interior)

MAINTENANCE FACTOR

CIE 154:2003


24/02/2012 AEC Illuminazione S.r.l. 4

MF = LMF x LLMFxLSF

LMF LLMF-LSF

IP degree Kind of source

Screen characteristics Operating Conditions of

Light source (Temperature, current)

Enviromental conditions

Design Life

Which parameters have an effect on these factors?

Luminaires maintenance factor (optical unit)

Depreciation factor of luminous flux of light

sources (LED)

MAINTENANCE FACTOR

CIE 154:2003


Why MF 0.8? On HID Luminaires is common practice to apply MF of 0.8

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LSF12kH = 0.98 LLMF12kH = 0.95

LSF X LLMF = 0,93aprox


Why MF 0.8? LMF: Luminaire Mainenence Factor

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MF= LMF x LSF x LLMF = 0.88 x 0.95 x 0.97 = 0.81 (Glass Diffuser) MF= LMF x LSF x LLMF = 0.81 x 0.95 x 0.97 = 0.74 (Plastic Diffuser)


MF= 0.8 Only if IP66 and Glass Diffuser

Why MF 0.8?

On HID Luminaires is common practice to apply MF of 0.8

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MF on LED Luminaires

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Life Time @ Lm output 80%

• Ta = 25°C

• LT@LM80 = 60khr


Life Time @ Lm output 70%

• Ta = 25°C

• LT@LM70 = 100khr


MF has to be related to Luminaire Lifetime Lxx

MF(*) 0.8 for a declared Lifetime of 66.900 hrs (L80)

MF (*) 0.7 for a declared Lifetime of 106.900 hrs (L70)

(*) Semplified not considering the LMF

For longer lasting life you need to overlit +30%

MF(*) 0.8 for a declared Lifetime of 106.900 hrs (L70)

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MORE ACCURATE WITH LMF

Different tecnologies on optical unit


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OPTICAL DESIGN HIGHER MAINTENANCE FACTOR

Plastics, Acrylic (PMMA – polymethyl methacrylate) and Polycarbonate (PC)

Degradation is generally from dirt and atmospheric contaminants, and material ageing. Inappropriate use of, or exposure to solvents can produce rapid degradation as the plastic structure is attacked. Regular cleaning with mild detergent and water will restore clarity. Remove intense grime with white spirit or other cleaners specifically formulated for PMMA or PC, and rinse well. Abrasives and scourers will demage the surface and add diffusion. Adhesives used in construction or fixings mus be compatible otherwise degradation (short to long term) may occur.

Polycarbonate

Its principal advantage over PMMA is its (initially) higher strength and resistance to impact. However the material degrades in the presence of UV – daylight, and UV – emitting lamps. The effect is accelerated by temperature. It is important therefore to keep the material service temperature below around 90° - 100°C, particularly when UV is present (e.g. by ensuring the lamp wattage used in the luminaire is limited appropriately). The degradation can be rapid.

Cie 154:2003


OPTICAL DESIGN

THE CHOICE OF GLASS RATHER THAN POLYCARBONATE LENSES HAS BEEN WELL EVALUATED AND PROVEN.

Long term depreciation of reflector and diffuser materials Outer glazing: Rifractors and diffusers: Glass Glass is easily cleaned to restore the original finish.

Cie 154:2003

HIGHER MAINTENANCE FACTOR

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Loss of transparency of different materials

GLASS

PMMA

POLYCARBONATE


Loss of transparency of different materials

• Ta = 25°C

• Loss < 10%

A well managed LED source can last longer than the optical unit!

LED after 25.00 hrs


Effects of a bad experience will be evident after a while…

MAINTENANCE FACTOR

CLOUR CHANGE!

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Loss of transparency can be faster than LED depreciation…..

MAINTENANCE FACTOR

COLOUR CHANGE! Abu Dhabi – 2 MONTHS AFTER INSTALLATION, ONLY.

350mA driven LED – SUPPOSED to be 6000K

6/3/2014


6/3/2014

MAINTENANCE FACTOR

MF = LMF x LSF x LLMF

Luminaire Maintenece

Factor optical unit

Lamp Survival Factor

mortality factor of the sources

Lamp Lumen Maintenence

Factor


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LMF LLMF

IP degree Light Source Type

Screen material and characteristics

Operating Conditions of Light source

(Temperature, current)

Enviromental conditions

Design Life

Which parameters have an effect on Maintenance factors ?

MAINTENANCE FACTOR FROM CIE 154:2003


6/3/2014

+ LMF

LLMF+LSF

PMMA

PC

GLASS

70%

75%

80%

85%

90%

95%

100%

10000 100000


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MAINTENANCE FACTOR

Which is th maintenence factor i have to consider to have the minimum lighting level required by the standard after 50.000 hrs?


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=

= x

x

MFGLASS (50khr) = 0,95 x 0,9 = 0,85 GLASS = 1 x 0,95 = 0,95

PC = 0,8 x 0,95 = 0,76

50khr = 0,9

50khr = 0,9 MFPC (50khr) = 0,76 x 0,9 = 0,68

70%

80%

90%

100%

10000 100000

70%

80%

90%

100%

10000 100000

70%

80%

90%

100%

10000 100000

70%

80%

90%

100%

10000 100000

Total MF 0,95

LMF(Screen+Dirty) LLMF+LSF(LED)


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ME3a

MFGLASS (50khr) = 0,95 x 0,9 = 0,85

MFPC (50khr) = 0,76 x 0,9 = 0,68

LED_IN 1B 4.5 72 – 9950 lm 115 W

EXPOSED LENSES – 9950 lm 115 W

ME3a

33 luminaries 3,8 kW/km

40 luminaries 4,6 kW/km

+20% power and luminaires


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MAINTENANCE FACTOR

Parameters to check:

- Operating Temperature

- Operating Current

- Optical Unit material

- Lasting Life Declared for the Luminaire

Enought?

NO!

The standards on how the parameters are delivered must be taken in consideration


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LASTING LIFE – B20L80 or IESNA TM21 Metric life Standard

reference Chip LED

manufacturers methodology employed critical failures Number of LEDs used in the

fitting

IESNA TM-21 (declared by AEC in all units)

And 'the only official standard America (IESNA)

ALL Based on a set of LEDs under test (test set by the standard IESNA LM-80. Reports are based on LM-80 test 6000-10000 hours at various temperatures and currents of a set of 25-100 LEDs. the measured values are used to extrapolate the values in the long term

It takes no account of the critical failures that may occur in the 6000-10000 hours of the LM-80 test. If they did the data extrapolated to long-term (es.50.000hr) would be strongly negative in terms of the life led by distorting the actual results. THE METHODOLOGY IS NOT 'TO SUTABLE FOR COPLETE LED LUMINAIRES!

Does not take into account whether aluminaire is composed of 1, 10 or 100 LEDs (consider what happens in a unit with 3 or with 100 LEDs when an LED is burned ...). And 'therefore useful to evaluate the life of the individual LEDs, but not the unit or module equipped with these LEDs.

BxxLyy LED (Declared by AEC devices with LEDs from OSRAM, then all of the first generation, the A2 LED relamping and DEKA)

EU standards on the way. EN 62717

OSRAM, SEOUL,e altri ma NO CREE

Based on a set of LED under test. There are no official reports as they are not regulated methods (the standard EN 62717 does not cover the test methodology, but only how to declare the data and their significance). The manufacturers give only the final result tabellato or curves. Theoretically, one can extrapolate from the LM-80 reports.

Here we introduce the concept of-Failure Fraction = fraction of failure Bxx is the fraction of the samples considered in which, within the stated time, the fault occurs Lyy. We distinguish: Bxx is the depreciation Cxx are critical failures Fxx is the combination of Bxx and Cxx The final wording is LyyFxx or LyyBxx ALSO THIS METHOD IS NOT 'SUITABLE FOR LUMINAIRES WITH MORE THAN 1 LED

Same as above


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LASTING LIFE – B20L80 or IESNA TM21 Metric life Standard

reference Chip LED

manufacturers methodology employed critical failures Number of LEDs used in the fitting

BxxLyy Luminaire (Declared by the AEC for all devices with LUMILEDS, so Italo and new generations Ledin, ILO, XMOD, RELAMPING TABLED))

No standard yet, but only the manufacturer's data .... For now only LUMILEDS declare the data in this form. NOT to be confused with the previous

LUMILEDS Based on the batch of LEDs under test + special statistical analysis to take account of the number of LEDs used into the luminaire

Here we introduce the concept of-Failure Fraction = fraction of failure Bxx is the fraction of the samples considered in which, within the stated time, the fault occurs Lyy. We distinguish: Bxx is the depreciation Cxx are critical failures Fxx is the combination of Bxx and Cxx The final wording is LyyFxx or LyyBxx THIS METHOD IS 'SUITABLE FOR COMPLETE LUMINAIRES

It takes into account how many LED fixture components. Only LUMILEDS provides this information, but does not disclose the algorithm. AEC developed an algorithm that, starting from reports LM-80 as a data base (then a base which is common to all manufacturers of LEDs and is regulated), by some statistical algorithms, manages to get the screw according to the number of LEDs in an apparatus.


6/3/2014

LASTING LIFE – L80F20 or IESNA TM21

Here we list the different ways of declaring the lasting life on datasheet from the most restrictive to the less restrictive one:

L80F20Luminaire: The statistic is considering the led mounted in the

luminaire’s optical unit, and it takes in consideration how many LED per luminaire and the Failure Rate is Included. F20 means that minimun the 80% of the equipement are following this rule. LLMFxLSF

L80F50Luminaire: The statistic is considering the led mounted in the

luminaire’s optical unit, and it takes in consideration how many LED per luminaire and the Failure Rate is Included. F20 means that minimun the 50% of the equipement are following this rule. LLMFxLSF


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LASTING LIFE – B20L80 or IESNA TM21


L80F20: The statistic is considering the LED onlyt. The Failure

Rate is Included. B20 means that minimun the 80% of the equipement are following this rule. LLMFxLSF

L80F50: The statistic is considering the LED onlyt. The Failure

Rate is Included. B50 means that minimun the 50% of the equipement are following this rule. LLMFxLSF


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LASTING LIFE – B20L80 or IESNA TM-21


IESNA TM-21: The statistic is considering the LED only. The Failure

Rate is NOT Included. The depreciation is the average depreciation of the lot (close to B50, but different method). LLMFF only


6/3/2014


Let’s compare the two different lasting life diagrams: B20


T-LED 0H x.7-36_B20_Ta25.pdf

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Let’s compare the two different lasting life diagrams: TM-21


T-LED 0H x.7-36_TM21_Ta25.pdf

6/3/2014


Let’s compare the two different lasting life diagrams: Overlap B20-TM-21


T-LED B20-TM21.pdf

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ITALO

WHAT TO CHECK ON THE PRODUCT SHEET

6/3/2014

ITALO

6/3/2014

ITALO

italo-1-product-sheet-1.pdf

6/3/2014

ITALO

THE PRODUCT SHEET MUST SPEAK CLEARLY

The product sheet is part of the contract between supplyer and customer therefore must be clear avoiding any kind of misundertoondings.

italo-1-product-sheet-1.pdf

SEE SOME EXAMPLES

Product Warranty & Latent Defect

A product warranty (http://en.wikipedia.org/wiki/Warranty) is covering from assembling defects. It means that the good is well designed for the scope, but that lot or that particular item has a defect (i.e. the guy in the assembly line is wrong operating on few items). Those kind of defects shows up in few months, not in years. So 5 years warranty is more than enough. If you ask to let them show you the competitors warranty terms, they all cover from assembly defects, and they not cover (like ours) failures caused by overvoltage or other external issues.


http://en.wikipedia.org/wiki/Warranty

Product Warranty & Latent Defect

An hidden or latent defect (http://en.wikipedia.org/wiki/Latent_defect) is a defect on wrong design of the good. The latent defect will appear also if the good is well assembled and installed. If a product has not a lifetime limit (like 70.000h L80) is very difficult for the customer to proof that what he bought is not performing as the expectation (like a car or a computer). In LED street lighting case, together with the good we deliver a datasheet, which is part of the contract where the lifetime is well described and the installation requirements are well specified by the user manual of the lantern. It means that if the lot of the product sold, is not respecting what written on datasheet, including lifetime. The customer can claim for latent defect.

Buying a luminaire where the performance and lasting life is not clearly show, put the customer in weak position – Warranty itself is not enough!


http://en.wikipedia.org/wiki/Latent_defect

Now the question is…

WHAT DID YOU CHOSE LAST TIME?

WHAT WILL YOU CHOSE NEXT TIME?


Thanks for the attention


Ing. Stefano Toti

[email protected]

Maintenance Factor on LED Lighting Calculations and ... · cie 154:2003 aec confidence on led...

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