Cree® XLamp® XM-L LED 10,000-Lumen High-Bay Reference Design Table of Contents Introduction Introduction......................................................... 1 This application note details the design of a replacement Design approach/objectives................................... 2 high-bay luminaire using Cree’s XLamp XM-L LED. The The 6-step methodology........................................ 2 high flux output and efficacy offered by the XM-L LED 1. Define lighting requirements............................. 2 make it a particularly strong candidate for use in a 2. Define design goals......................................... 5 high-bay luminaire. The performance of the XM-L LED 3. Estimate efficiencies of the optical, thermal & means that it is not necessary to use hundreds of LEDs electrical systems........................................... 5 4.Calculate the number of LEDs........................... 8 CLD-AP96 rev 0A application note to match the light output of traditional metal halide and fluorescent high-bay lighting. 5.Consider all design possibilities......................... 8 www. cree.com/Xlamp 6. Complete the final steps: implementation and An XM-L LED-based high-bay luminaire not only offers analysis......................................................... 9 energy efficiency benefits but its long lifetime also Conclusions........................................................14 reduces maintenance costs in typically hard-to-reach Special thanks....................................................14 industrial and commercial applications. Reliance on any of the information provided in this Application Note is at the user’s sole risk. Cree and its affiliates make no warranties or representations about, nor assume any liability with respect to, the information in this document or any LED-based lamp or luminaire made in accordance with this reference design, including without limitation that the lamps or luminaires will not infringe the intellectual property rights of Cree or a third party. Luminaire manufacturers who base product designs in whole or part on any Cree Application Note or Reference Design are solely responsible for the compliance of their products with all applicable laws and industry requirements. Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo Copyright ©® 2010 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. and XLamp are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For Cree, the Cree logo and XLamp are registered trademarks of Cree, Inc. warranty information, please contact Cree Sales at [email protected]. Other trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. Cree, Inc. 4600 Silicon Drive Durham, NC 27703 USA Tel: +1.919.313.5300 XLamp xm-l 10,000-lumen High-bay Reference Design Design approach/objectives In the “LED Luminaire Design Guide”1 Cree advocates a six step framework for creating LED luminaires and lamps. All Cree reference designs use this framework, and the design guide’s summary table is reproduced below. Step Explanation 1. Define lighting requirements 2. Define design goals 3. Estimate efficiencies of the thermal & electrical systems optical, 4. Calculate the number of LEDs needed 5. Consider all design choose the best possibilities and 6. Complete final steps • The design goals can be based either on an existing fixture or on the application’s lighting requirements. • • Specify design goals, which will be based on the application’s lighting requirements. Specify any other goals that will influence the design, such as special optical or environmental requirements. • • • Design goals will place constraints on the optical, thermal and electrical systems. Good estimations of efficiencies of each system can be made based on these constraints. The combination of lighting goals and system effiiciencies will drive the number of LEDs needed in the luminaire. • Based on the design goals and estimated losses, the designer can calculate the number of LEDs to meet the design goals. • • With any design, there are many ways to achieve the goals. LED lighting is a new field; assumptions that work for conventional lighting sources may not apply. • • • • • Complete circuit board layout. Test design choices by building a prototype luminaire. Make sure the design achieves all the design goals. Use the prototype to further refine the luminaire design. Record observations and ideas for improvement. Table 1: Cree 6-step framework The 6-step methodology The goal of the design is an LED-based high-bay luminaire that can replace high-intensity discharge (HID) and 54-watt fluorescent T5 and T8 luminaires in commercial, industrial and warehouse applications. As a replacement luminaire, this design uses a form factor that is similar to traditional high-bay lighting currently in use. 1. Define lighting requirements Table 2 shows a ranked list of desirable characteristics to address in a high-bay luminaire design. Importance Critical Characteristics Units Illuminance distribution footcandles (fc)/lux (lx) Electrical power watts (W) Lifetime hours Luminous flux lumens (lm) Manufacturability 1 LED Luminaire Design Guide, Application Note AP15, www.cree.com/xlamp_app_notes/luminaire_design_guide Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 2 XLamp xm-l 10,000-lumen High-bay Reference Design Importance Important Characteristics Units Operating temperatures °C Operating humidity % RH Correlated Color Temperature (CCT) K Color Rendering Index (CRI) 100-point scale Ease of installation Table 2: Ranked design criteria for a high-bay luminaire Table 3 summarizes the ENERGY STAR® requirements for solid-state luminaires.2 There are no ENERGY STAR requirements for high-bay luminaires. Characteristic Requirements Light source life requirements: all luminaires The LED package(s) / LED module(s) / LED array(s), including those incorporated into LED light engines or GU24 based integrated LED lamps, shall meet the following L70 lumen maintenance life values (refer to Lumen Maintenance Requirements in the next section): • • • 25,000 hours for residential grade indoor luminaires 35,000 hours for residential grade outdoor luminaires 35,000 hours for commercial grade luminaires Lumen maintenance life projection claims in excess of the above requirements shall be substantiated with a TM-21 lumen maintenance life projection report. Lumen maintenance requirements: directional and non-directional luminaires The LED package(s) / module(s) / array(s), including those incorporated into LED light engines or GU24 based integrated LED lamps, shall meet the following • • • L70(6k) rated lumen maintenance life values, in situ: L70(6k) ≥ 25,000 hours for residential indoor L70(6k) ≥ 35,000 hours for residential outdoor, or commercial Compliance with the above shall be documented with a TM-21 lumen maintenance life projection report as detailed in TM-21, section 7. The report shall be generated using data from the LM-80 test report for the employed LED package/module/array model (“device”), the forward drive current applied to each device, and the in situ TMPLED temperature of the hottest LED in the luminaire. In addition to LM-80 reporting requirements, the following information shall be reported: • • • • • • sampling method and sample size (per LM-80 section 4.3) test results for each TS and drive current combination description of device including model number and whether device is an LED package, module or array (see Definitions) ANSI target, and calculated CCT value(s) for each device in sample set Δ u’v’ chromaticity shift value on the CIE 1976 diagram for each device in sample set a detailed rationale, with supporting data, for application of results to other devices (e.g. LED packages with other CCTs) Access to the TMPLED for the hottest LED may be accomplished via a minimally sized hole in the luminaire housing, tightly resealed with a suitable sealant if created for purposes of testing. All thermocouple attachments and intrusions to luminaire housing shall be photographed. CCT requirements: all indoor luminaires The luminaire (directional luminaires), or replaceable LED light engine or GU24 based integrated LED lamp (nondirectional luminaires) shall have one of the following nominal CCTs: • • • • • 2700 3000 3500 4000 5000 Kelvin Kelvin Kelvin Kelvin Kelvin (commercial only) The luminaire, LED light engine or GU24 based integrated LED lamp shall also fall within the corresponding 7-step chromaticity quadrangles as defined in ANSI/NEMA/ANSLG C78.377-2008. Color rendering requirements: all indoor luminaires The luminaire (directional luminaires), or replaceable LED light engine or GU24 based integrated LED lamp (nondirectional luminaires) shall meet or exceed Ra ≥ 80. 2 ENERGY STAR Program Requirements, Product Specification for Luminaires (Light Fixtures), Eligibility Criteria, Version 1.1, www. energystar.gov/ia/partners/prod_development/new_specs/downloads/luminaires/Final_Luminaires_Program_Requirements.pdf Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 3 XLamp xm-l 10,000-lumen High-bay Reference Design Characteristic Requirements Color angular uniformity requirements: directional solid state indoor luminaires Throughout the zonal lumen density angles detailed above, and five degrees beyond, the variation of chromaticity shall be within 0.004 from the weighted average point on the CIE 1976 (u’,v’) diagram. Color maintenance requirements: solid state indoor luminaires only The change of chromaticity over the first 6,000 hours of luminaire operation shall be within 0.007 on the CIE 1976 (u’,v’) diagram, as demonstrated by either: Source start time requirement: directional and non-directional luminaires Light source shall remain continuously illuminated within one second of application of electrical power. Source run-up time requirements: directional and non-directional luminaires Light source shall reach 90% of stabilized lumen output within one minute of application of electrical power. Power factor requirements: directional and non-directional luminaires Total luminaire input power less than or equal to 5 watts: PF ≥ 0.5 Transient protection requirements: all luminaires Ballast or driver shall comply with ANSI/IEEE C62.41.1-2002 and ANSI/IEEE C62.41.2-2002, Class A operation. The line transient shall consist of seven strikes of a 100 kHz ring wave, 2.5 kV level, for both common mode and differential mode. Operating frequency requirements: directional and non-directional luminaires Frequency ≥ 120 Hz Noise requirements: directional and non-directional luminaires All ballasts & drivers used within the luminaire shall have a Class A sound rating. Electromagnetic and radio frequency interference requirements: directional and non-directional luminaires Power supplies and/or drivers shall meet FCC requirements: • • • the IES LM-80 test report for the employed LED package/array/module model, or as demonstrated by a comparison of luminaire chromaticity data in LM-79 reports at zero and 6,000 hours, or as demonstrated by a comparison of LED light engine or GU24 based integrated LED lamp chromaticity data in LM-82 reports at zero and 6,000 hours. Total luminaire input power greater than 5 watts: Residential: PF ≥ 0.7 Commercial: PF ≥ 0.9 Note: This performance characteristic addresses problems with visible flicker due to low frequency operation and applies to steady-state as well as dimmed operation. Dimming operation shall meet the requirement at all light output levels. Ballasts and drivers are recommended to be installed in the luminaire in such a way that in operation, the luminaire will not emit sound exceeding a measured level of 24 BA. • • Class A for power supplies or drivers that are marketed for use in a commercial, industrial or business environment, exclusive of a device which is marketed for use by the general public or is intended to be used in the home. Class B for power supplies or drivers that are marketed for use in a residential environment notwithstanding use in commercial, business and industrial environments. Table 3: ENERGY STAR luminaire requirements The DesignLights™ Consortium provides requirements for a high-bay luminaire.3 Application Characteristic Minimum light output Zonal lumen density High-Bay and Low-Bay Fixtures for Commercial and Industrial Buildings High-Bay-Aisle Lighting 10,000 lm 10,000 lm ≥ 30% 20–50° ≥ 50%, 20–50° ≥ 30%, 0–20° Minimum luminaire efficacy 70 lm/W 60 lm/W Allowable CCTs (ANSI C78.377-2008) < 5700 K < 6000 K Minimum CRI L70 lumen maintenance Minimum luminaire warranty 70 70 35,000 hours 35,000 hours 5 years 5 years Table 4: DesignLights Consortium high-bay luminaire requirements 3 Technical Requirements Table v1.6, DesignLights Consortium Qualified Products List - Non-Residential Applications, www.designlights. org/solidstate.manufacturer.requirements.php Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 4 XLamp xm-l 10,000-lumen High-bay Reference Design 2. Define design goals Table 5 shows the design goals for this project. Characteristic Unit Minimum Goal Target Goal Light output lm 10,000 10,000 Power W 150 < 150 Luminaire efficacy lm/W 66 70 Lifetime hours 50,000 50,000 CCT K 5,000 5,000 CRI 100-point scale Power factor 75 > 75 0.9 > 0.9 Table 5: Design goals 3. Estimate efficiencies of the optical, thermal & electrical systems We used Cree’s Product Characterization Tool (PCT) tool to determine the drive current for the design.4 For the 10,000-lm target, we estimated 93% optical efficiency and 85% driver efficiency. We also estimated a solder point temperature of 85 °C. LED System Comparison Rep The PCT output highlighted in Figure 1 shows that, at 2.4 A, sixteen XM-L LEDs provide sufficient light output to meet 1 the design goals. System: 10,000 Target Lumens : 93 Optical Efficiency: Current (A) LED 1 Model Flux Optic Tj (ºC) T6 [280] Price SYS # LED SYS lm tot 1.500 23 1.600 22 1.700 21 1.800 20 1.900 19 2.000 18 2.200 17 2.400 16 2.600 15 2.800 15 3.000 14 0.000 #N/A Figure 1: PCT view of the LED 2 Model Cree XLamp XM-L {CW/NW/WW} $ 85 10225.8 10313.8 10338.8 10302.9 10208.3 10056.9 10191.8 10200.8 10092.2 10579.7 10290.6 #N/A of number Flux Price - SYS W 120.09 123.5 126.17 128.1 129.26 129.65 136.04 140.81 143.89 155.62 155.99 #N/A used LEDs (none) Tj (ºC) $ 2 - SYS lm/W 85.1 #N/A 83.5 #N/A 81.9 #N/A 80.4 #N/A 79 #N/A 77.6 #N/A 74.9 #N/A 72.4 #N/A 70.1 #N/A 68 #N/A 66 #N/A #N/A #N/A and drive current #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A This document is provided for informational purposes only and is not a warranty or a specification. For product specifications, please see the data Copyright © 2009-2011 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree, the Cree logo a Because this reference design is targeted as a replacement high-bay luminaire, the design has a form factor similar to incumbent luminaires. The optic is a commercially available 16-inch diameter reflector commonly used in HID high-bay 4PCT is available at pct.cree.com Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 5 XLamp xm-l 10,000-lumen High-bay Reference Design luminaires. The LED array size and arrangement is designed to fit this reflector. To maximize the luminaire’s light output, we painted the inside of the reflector with reflective white paint. Figure 2: High-bay reflector Thermal Requirements The thermal solution is a key factor in the success of this reference design, as the LEDs are concentrated at the center of the luminaire. To make this design feasible, we worked with two partners to design and fabricate a custom metal core printed circuit board (MCPCB) and heat sink. MCPCB As shown in Figure 4, this high-bay luminaire design has sixteen XLamp XM-L LEDs arranged in a closely spaced 4 x 4 rectangular array. To handle the high power density we used a special copper MCPCB from Rayben.5 As shown in Figure 3, where a typical MCPCB has a copper trace layer and a dielectric layer to transfer heat to the aluminum base layer and on to the surrounding environment, the Rayben MCPCB in this design has a “micro heat exchanger” (MHE) layer to transfer heat to the copper base layer and offers greater heat transfer capability. The electrically neutral thermal path of the XM-L LED makes this possible. Figure 3: MHE thermal substrate 5Model MHE 301, Rayben, www.rayben.com/English/contact/contact.asp Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 6 XLamp xm-l 10,000-lumen High-bay Reference Design Figure 4: MCPCB with XM-L LEDs Heat Sink This reference design uses a custom vapor-chamber heat sink by Steady Heat & Mass Transfer Technology Academy Ltd, shown in Figure 6.6 As Figure 5 illustrates, the heat sink has a unique vapor chamber design to enhance thermal conductivity and heat dissipation. A special liquid is vacuum sealed in a chamber formed between the heat source, in this design the MCPCB, and the heat fins. The heat from the MCPCB causes the liquid to evaporate; the vapor condenses on the cooler part of the chamber to enhance cooling and collects on the base near the heat source to repeat the cycle. Figure 5: Heat sink design Figure 6: Heat sink attached to heat sink support 6 Model HBEXC-98D160L200-S, Steady Heat & Mass Transfer Technology Academy Ltd., www.cnvc.cc Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 7 XLamp xm-l 10,000-lumen High-bay Reference Design We performed thermal simulations to verify this thermal design is sufficient. Figure 7 shows the thermal simulation results for the design. The simulated solder point temperature (TSP) is 72 °C. Figure 7: Thermal simulation of XM-L high-bay heat sink Driver We used a market-ready constant-current driver that fits within the heat sink support and matches the design’s current and voltage range.7 The high-bay luminaire design can also accommodate locating the driver separate from the luminaire. Figure 8: Driver 4. Calculate the number of LEDs Using Cree’s PCT, we determined that sixteen XLamp XM-L LEDs produce sufficient light to meet the 10,000-lm design goal. 5. Consider all design possibilities There are many ways to design an LED-based high-bay luminaire. This reference design aims to show that the XM-L LED enables a high-bay luminaire offering superior performance. The XM-L LED offers a wide range of color temperatures. We selected a neutral white LED for this high-bay luminaire design, shown highlighted in Table 6. 7Model HLG-150-54A, Mean Well USA, Inc., www.meanwellusa.com Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 8 XLamp xm-l 10,000-lumen High-bay Reference Design AME : 10875-G.IES CCT Range Color Min. MATION (From Photometric File) Neutral White 3,700 K Max. 5,000 K Base Order Codes Min. Luminous Flux @ 700 mA (lm) Order Code Group Flux (lm) T4 240 XMLAWT-00-0000-000LT40E3 T5 260 XMLAWT-00-0000-000LT50E3 T6 280 XMLAWT-00-0000-000LT60E3 Table 6: XM-L order codes 6. Complete the final steps: implementation and analysis 2 Bay Reference Design Using the methodology described above, we determined a suitable combination of LEDs, components and drive conditions. This section describes how Cree assembled the high-bay luminaire and shows the results of the design. e Textured High Bay Reflector Prototyping Details We verified the dimensions to ensure a correct fit. NAIRE1.OUTPUT = component 10443 LM Following the recommendations in Cree’s Soldering and Handling 6 VDC2.and 113.7 Watts Application Note for the XM-L LED, with an appropriate solder paste and reflow profile, we reflow soldered the LEDs to the MCPCB.8 3. We ran the LED DC input wires through an enclosed channel in the heat sink. The channel runs the length of the heat sink and insulates the LED DC input wires from the heat and moisture in the heat sink. 4. We soldered the LED DC input wires to the MCPCB. N.A. (absolute) lit up. N.A. (absolute) 6. We applied a thin layer10463 of thermal conductive compound to the back of MCPCB and attached it to the heat sink with screws. cy N.A. 7. We secured the heat sink support to the end of the heat sink with screws. ng (LER) 92 8. We connected the LED DC input wires to the driver DC output wires with 113.7 connectors. 1.00 9. We fit the LED driver into the heat sink support. This is an optional step as the Directtype. This driver can be located apart from the driver is a remote standalone 0) 0.64 luminaire or a centralized dedicated power line can be directly wired to the 70) 0.64 luminaire. to the heat sink with screws. onal) 10.We secured the reflector 1.00 11.We performed final testing Circular 0) 0.00 ft 0) 1.33 ft (Diameter) 0.00 ft 5. We tested the connection by applying power to the LEDs and verified the LEDs Figure 9: Assembled high-bay luminaire ready to test 8Cree XLamp XM-L LED Soldering and Handling, Application Note AP54, www.cree.com/~/media/Files/Cree/LED%20Components%20 and%20Modules/XLamp/XLamp%20Application%20Notes/XLampXM_SolderingandHandling.pdf /sq.m) e Average 45-Deg Average 90-Deg Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 9 XLamp xm-l 10,000-lumen High-bay Reference Design Results Thermal Results Cree verified the board temperature with a thermocouple to confirm that the thermal dissipation performance of the heat sink aligns with our simulation. As shown in Figure 10, the measured solder point temperature was 61 °C, which shows that the heat sink is sufficient for this design. TSP Solder Point Temperature 61 °C T2 PCB Temperature T3 Heat Sink Temperature 56 °C 50 °C Figure 10: Thermal measurement Based on the measured solder point temperature of 61 °C, the junction temperature (TJ) can be calculated as follows. TJ = TSP + (LED power * LED thermal resistance) TJ = 61 °C + (7.8 W * 2.5 °C/W) TJ = 81 °C Estimated LED lifetime Figure 11 shows the calculated and reported lifetimes, determined using the TM-21 projection algorithm, for the XM-L LED at a 2-A input current at three solder point temperatures. The duration of Cree’s XM-L HEW LM-80 data set is 6000 hours at a 2-A drive current. The TM-21 methodology limits the projection to six times the duration of the LM-80 data set. Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 10 XLamp xm-l 10,000-lumen High-bay Reference Design TM-21 Lifetime Report LED I Data Set Tsp Sample Size Test Duration α β Calculated Lifetime Reported Lifetime 1 45°C 25 6,048 hrs 1.459E-07 9.847E-01 L70(6k) = 2,340,000 hours L70(6k) > 36,300 hours XLamp XM-L White 2000 mA 2 55°C 25 6,048 hrs 9.543E-07 9.887E-01 L70(6k) = 362,000 hours L70(6k) > 36,300 hours 3 85°C 25 6,048 hrs 2.155E-06 9.834E-01 L70(6k) = 158,000 hours L70(6k) > 36,300 hours Reported Calculated Reported 110 105 100 95 % Luminous Flux 90 85 45°C (LM-80) 80 55°C (LM-80) 85°C (LM-80) 75 45°C (TM-21) 70 55°C (TM-21) 65 85°C (TM-21) 60 55 50 1,000 10,000 100,000 1,000,000 10,000,000 Time (hours) Figure 11: XM-L TM-21 data Figure showsis the calculated and reported XM-L or LED, interpolated from the data shown Figure 11, This 12 document provided for informational purposeslifetimes only and is for not the a warranty a specification. For product specifications, pleaseinsee the datameasured sheets available at www.cree.com. at the 61 °C TSP for the XM-L LED in this design. Although this design operates at a slightly higher current Copyright © 2011 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree, the Cree logo and thanXLamp the 2-A level oftrademarks the TM-21 dataInc. set, Cree’s experience with the XM-L LED gives us reason to expect that, with a are registered of Cree, reported L70(6k) lifetime greater than 36,300 hours and a calculated L70(6k) lifetime of 302,000 hours at 2 A, the Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 11 XLamp xm-l 10,000-lumen High-bay Reference Design TM-21 Lifetime Report high-bay luminaire to easily meet the 35,000-hour DesignLights Consortium L70 lumen maintenance requirement when operating at a measured 2.3 A.9 Ts1 XLamp XM-L White 2000 mA Tsi (Interpolated) Ts2 55°C 61°C 85°C 328.15 K 334.15 K 3191.23 1.5965E-02 1.136E-06 9.861E-01 L70(6k) = 302,000 hours L70(6k) > 36,300 hours L70(6k) = 302,000 hours L70(6k) > 36,300 hours 358.15 K LED I Tsp Tsp Ea/kB A α β Calculated L70 Reported L70 Calculated Lifetime Reported Lifetime 9.543E-07 9.887E-01 L70(6k) = 362,000 hours L70(6k) > 36,300 hours 110 45°C (LM-80) 105 % Luminous Flux 2.155E-06 9.834E-01 L70(6k) = 158,000 hours L70(6k) > 36,300 hours 55°C (LM-80) 100 85°C (LM-80) 95 45°C (TM-21) 90 55°C (TM-21) 85°C (TM-21) 85 61°C (LM-80) 80 75 L70: 302,000hrs 70 65 60 55 50 1,000 10,000 100,000 1,000,000 10,000,000 Time (hours) Figure 12: XM-L TM-21 data with TSP = 61 °C This document is provided for informational purposes only and is not a warranty or a specification. For product specifications, please see the data sheets available at www.cree.com. 9 That is, after 35,000 hours of operation, the LED will still deliver at least 70% of its initial luminous flux. Copyright © 2011 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree, the Cree logo and XLamp are registered trademarks of Cree, Inc. Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 12 XLamp xm-l 10,000-lumen High-bay Reference Design Optical and Electrical Results We obtained the results in Table 7 by testing the luminaire in a 2-meter sphere at steady state.10 As the table shows, the luminaire meets the 10,000-lm target goal using less than 150 W of power and compares favorably with published data for two comparison metal halide luminaires. The XM-L high-bay luminaire also exceeds the DesignLights Consortium efficacy, CCT and CRI requirements. Unit DesignLights Consortium High-Bay Requirement Comparison Metal Halide High-Bay Luminaire Comparison Pulse Start Metal Halide High-Bay Luminaire XM-L High-Bay Luminaire Result Luminous flux lm 10,000 10,427 9,676 10,737 Power W - 175 150 125 Characteristic Luminaire efficacy lm/W 70 64 66 86 CCT K < 5,700 K ~ 5,000 ~ 5,000 5,154 CRI 100-point scale 70 65 65 75 A - Current 2.3 Table 7: XM-L high-bay luminaire steady-state results Goniometric measurements show a consistent beam shape and light distribution for the XM-L high-bay luminaire.11 8802 6602 4401 2201 Figure 13: Angular luminous intensity distribution of XM-L high-bay luminaire The light intensity and distribution data in Table 8 show the XM-L high-bay luminaire effectively illuminates the area in which it is installed. 10Testing was performed at Cree’s Durham Technology Center. 11Ibid. IES files for the high-bay luminaire are available at www.cree.com/~/media/Files/Cree/LED%20Components%20and%20Modules/ XLamp/XLamp%20Reference%20Designs/Design%20files/ xml_high-bay_ies. Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 13 XLamp xm-l 10,000-lumen High-bay Reference Design Height Illuminance Diameter 1.3 m 4.2 ft 507.0 fc 5457.4 lx 1.3 m 4.3 ft 2.5 m 8.3 ft 126.8 fc 1374.3 lx 2.6 m 8.5 ft 3.8 m 12.5 ft 56.3 fc 606.3 lx 3.9 m 12.8 ft 5.7 m 16.7 ft 31.7 fc 341.0 lx 5.2 m 17.1 ft 6.3 m 20.8 ft 20.3 fc 218.3 lx 6.5 m 21.4 ft 7.6 m 25.0 ft 14.1 fc 151.6 lx 7.8 m 25.6 ft Table 8: XM-L high-bay light intensity and distribution Conclusions This reference design illustrates the excellent performance of a high-bay luminaire based on the Cree XLamp XM-L LED. The efficacy of the XM-L LED allows a relatively small number of LEDs to match the light output of comparison luminaires with better color consistency without the metal halide’s slow start-up times and ultraviolet light. The lighting-class performance of the Cree XLamp XM-L LED makes it an attractive design option for an LED-based high-bay luminaire. Special thanks Cree would like to acknowledge and thank the following partner companies that collaborated in the successful prototyping of this luminaire. • Rayben • Steady Heat & Mass Transfer Technology Academy Ltd. Reliance on any of the information provided in this Application Note is at the user’s sole risk. Cree and its affiliates make no warranties or representations about, nor assume any liability with respect to, the information in this document or any LED-based lamp or luminaire made in accordance with this reference design, including without limitation that the lamps or luminaires will not infringe the intellectual property rights of Cree or a third party. Luminaire manufacturers who base product designs in whole or part on any Cree Application Note or Reference Design are solely responsible for the compliance of their products with all applicable laws and industry requirements. Copyright © 2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 14