Frequently Asked Questions
Most Frequently Asked Questions
What are the advantages to using LED luminaires?
LEDs bring several advantages to the lighting industry, including high efficacy and durability, and, with superior life over other lamp sources, their required maintenance is greatly reduced. This translates into energy savings, maintenance savings, and environmental sustainability. There is also the potential for greater optical control (more controllable source), dimming, instant on/off, and reduced rate of lumen depreciation (potential for long application life).
How do you verify the performance of your products?
The performance of all of our products is verified by accredited independent 3rd party laboratories.
How many LED fixtures do I need compared to other sources, i.e., incandescent, CFL, etc.?
There are many different types of lighting, housings, trims, accessories, and lamp types available. Please refer to the Product Spec Sheet for photometry information.
Why does the identical LED chip package lumen depreciate at different rates from manufacturer to manufacturer?
Unlike previous technologies, LED manufacturers have a much greater impact on the rate of lumen depreciation based on their luminaire designs. Thermal design plays a critical role in the rate of lumen depreciation. Therefore you should see variation in lumen depreciation from manufacturer to manufacturer, as well as within different product families offered by the same manufacturer.
Are Cree LED lights ultra-efficient?
Compared to conventional technologies, Cree LED Lighting products can deliver the same amount of light using as little as 10 to 15% of the power. This huge reduction in energy consumption can enable consumers to save hundreds of dollars over the life of each light.
The Value of Cree LED Lighting
A Cree LED Lighting product, like the LR6TM downlight, can replace a 65 watt light while using only 10.5 watts. In its 50,000 hour lifetime it will consume about 525 kilowatt-hours, costing about $63. During that time, it will never need to be replaced.
The Cost of Incandescent Lamps
A typical 65 watt light lasts for 2,000 hours. To match the light output and longevity of a Cree LED Lighting downlight, traditional lighting would consume 3,250 kilowatt-hours, and need to be replaced about 25 times, costing over $465.
It's a simple story...saving over $400 in electric and relamping costs, for every downlight you replace.
Are your products consistent in color and/or intensity?
Our products are all designed to meet ENERGY STAR® requirements for spatial uniformity, meaning they must all be within 4 equivalent MacAdam ellipses.
Do Cree LED lights produce UV and/or IR emissions?
Unlike incandescent and fluorescent light sources, Cree LED Lighting products produce virtually no light in the ultraviolet (UV) or infrared (IR) spectrums.
What does "Lifetime 50,000 hours" mean?
Useful life has been defined as the number of hours an LED device can operate until it emits only a certain percentage of its original lumen output. For general illumination applications, vision research suggests that 70 percent of original lumen output is the level where end users begin to notice a drop in light levels. This metric is indicated as L70. The Illuminating Engineering Society of North America (IESNA) published LM-80-08, IES Approved Method for Measuring Lumen Maintenance of LED Light Sources. Cree tested our LED lamps for long-term lumen maintenance consistent with LM-80 methods to demonstrate L70 life after more than 6,000 hours of testing and got the number 50,000 hours under normal operating conditions. Also the performance of all of our products is verified by accredited independent 3rd party laboratories. Please note, any initial condition or parameter change will affect the useful life of LEDs in different ways.
What's the difference between 2700K and 3500K?
Correlated Color Temperature (CCT) is defined as the color of light given off by a particular light source that most closely represents the light emitted from a perfect blackbody radiator when heated to a certain temperature.
Why are LEDs considered a GREEN technology?
LEDs are environmentally friendly on many fronts. First, unlike HID (High Intensity Discharge) lamps LEDs contain NO mercury. In addition, some LED luminaires are RoHS (Restriction of Hazardous Substances) compliant and have been designed to provide more than a decade of near maintenance-free service. That means no re-lamping which means no waste.
Assuming an HID fixture is re-lamped every two years, that’s five re-lamping cycles over a 10 year period.
Just imagine the benefits of choosing LED:
- No concern over proper disposal (hopefully not simply thrown in a landfill) of old HID lamps containing harmful mercury.
- No fuel used and the accompanying pollution to service those fixtures.
- Greatly reduced potential for lane closures and other productivity and inconvenience-related costs associated with maintaining an HID system.
- No natural resources lost to produce the replacement lamps that contain mercury.
- No fuel used to move old-technology lamps from the factory (most likely overseas), to the distributor, to the contractor, to the job site.
It's important to keep in mind all the positive and powerful ripple effects that using LED technology can have on the environment.
Are your fixtures/housings fire rated?
Fire rating depends on the housing, and currently none of our housings are fire rated. Our downlight products are designed for fire rated housings.
Are your products plenum rated?
We do not currently offer any plenum rated products.
Are your products compliant with the Trade Agreements Act (TAA)?
TAA Compliant Products
TAA refers to the Trade Agreements Act (19 U.S.C. & 2501-2581), which is intended to foster fair and open international trade. TAA requires that the U.S. Government may acquire only “US-made or designated country end products."
This act requires that contractors must certify that each end product meets the applicable requirements. End products are "those articles, materials and supplies to be acquired for public use.” This includes items which have been “substantially transformed” in the U.S.
Cree’s TAA compliant products are manufactured and/or assembled in the U.S. and are approved to be acquired by the U.S. Government for use. These products are also compliant with GSA Schedules.
The following products are only TAA compliant when the designation -US is included in the ordering number, which specifies that the product is "U.S. Manufactured."
LR6TM Family: LR6 LR6-DR650 LR6-DR1000 LR6-277V LR6-DR1000-277V
LE6
Architectural Troffers - CR Series: CR24 CR22 CR14
2' x 2' Architectural Lay-ins - LR24TM Family: LR24-32SKA35 LR24-38SKA35
Can a CFL housing be converted to LED?
If the CFL housing is pin-based with an integral housing, then no. If the CFL housing is an incandescent housing with a CFL installed in it, then refer to the Recommended Housing List for compatibility.
General
What are the advantages to using LED luminaires?
LEDs bring several advantages to the lighting industry, including high efficacy and durability, and, with superior life over other lamp sources, their required maintenance is greatly reduced. This translates into energy savings, maintenance savings, and environmental sustainability. There is also the potential for greater optical control (more controllable source), dimming, instant on/off, and reduced rate of lumen depreciation (potential for long application life).
How do you verify the performance of your products?
The performance of all of our products is verified by accredited independent 3rd party laboratories.
How many LED fixtures do I need compared to other sources, i.e., incandescent, CFL, etc.?
There are many different types of lighting, housings, trims, accessories, and lamp types available. Please refer to the Product Spec Sheet for photometry information.
Why does the identical LED chip package lumen depreciate at different rates from manufacturer to manufacturer?
Unlike previous technologies, LED manufacturers have a much greater impact on the rate of lumen depreciation based on their luminaire designs. Thermal design plays a critical role in the rate of lumen depreciation. Therefore you should see variation in lumen depreciation from manufacturer to manufacturer, as well as within different product families offered by the same manufacturer.
Are Cree LED lights ultra-efficient?
Compared to conventional technologies, Cree LED Lighting products can deliver the same amount of light using as little as 10 to 15% of the power. This huge reduction in energy consumption can enable consumers to save hundreds of dollars over the life of each light.
The Value of Cree LED Lighting
A Cree LED Lighting product, like the LR6TM downlight, can replace a 65 watt light while using only 10.5 watts. In its 50,000 hour lifetime it will consume about 525 kilowatt-hours, costing about $63. During that time, it will never need to be replaced.
The Cost of Incandescent Lamps
A typical 65 watt light lasts for 2,000 hours. To match the light output and longevity of a Cree LED Lighting downlight, traditional lighting would consume 3,250 kilowatt-hours, and need to be replaced about 25 times, costing over $465.
It's a simple story...saving over $400 in electric and relamping costs, for every downlight you replace.
Are your products consistent in color and/or intensity?
Our products are all designed to meet ENERGY STAR® requirements for spatial uniformity, meaning they must all be within 4 equivalent MacAdam ellipses.
How does ambient temperature affect LED efficiency?
LED fixtures must be designed with junction temperature thermal management as a key component and use the correct LEDs. These products will then be robust enough to operate in most ambient temperature applications. Unlike fluorescent sources, cold temperatures do not impact the performance of LEDs.
If an LED fixture has lower initial lumen output than a traditional HID light, how can LED claim to deliver lumens more efficiently than HID?
When you average delivered lumens over the course of 60,000 hours, you'll see that LED outperforms a 400-watt MH lamp operated in a horizontal position. (60,000 hours is used for this comparison to show three full life cycles of the HID.)
The MH's lumen depreciation, as well as optical and ballast losses, quickly reduce output of the HID system. Note that there are three relamps over 60,000 hours.
Conversely, LED has significantly better lumen maintenance and a more efficient driver. Also note that the LED fixture typically doesn't need relamping from zero to 60,000 hours.
Combine this with Beta's exclusive NanoOptic® and LED outperforms MH over the course of the life of the fixture.
Result: the LED's average delivered lumens is 74% higher than HID over 60,000 hours.
How long is 100,000 hours?
Based on how long a fixture is illuminated per day, here's what 100,000 works out to:
Hours of Operation: 100,000 hours is:
24 hours a day 11.4 years
18 hours per day 14.8 years
12 hours per day 22.8 years
8 hours per day 34.2 years
How much are your products?
Cree LED Lighting products are sold through distribution. The following link will help you to locate your closest Cree LED Lighting distributor for pricing requests:
Is Cree an Energy Star® partner?
As an ENERGY STAR® partner, Cree LED Lighting supports the ENERGY STAR program and its efforts to inform consumers and to protect our environment for future generations. Products that earn the ENERGY STAR for Solid-State Lighting meet energy efficiency and performance guidelines set by the U.S. Department of Energy. These guidelines help to protect consumers' interests by ensuring that qualifying products meet certain efficacy, lifetime, color rendering and color quality specifications. Cree LED Lighting is proud to offer a variety of ENERGY STAR qualified products, which meet and exceed these guidelines.
| Performance Values for LED Downlights | ENERGY STAR® partner Minimums | Cree LED Lighting |
| Efficacy | 35 LPW | 46 to 80 LPW |
| Color Rendering Index | 75 | 90 |
| Rated Lifetime | 25,000 hours | 50,000 hours |
| Minimum Lumen Output ≤4.5" diameter | 375 lumens | 515 or 540 lumens |
| Minimum Lumen Output >4.5" diameter | 575 lumens | 650 or 1000 lumens |
Is each Cree LED Lighting product tested before it is shipped?
Yes, each Cree LED Lighting product is individually tested and tuned to the optimal color point before shipment.
Isn’t a lumen, a lumen (spec sheet comparisons)?
The Illumination Engineering Society (IES) classifies varying light distribution patterns into different categories or “types” (i.e., Type II, Type III, etc.), but within these classifications are a fair amount of variation. For example, two manufacturers may both have products that are classified as a “Type III” distribution, but from a light distribution standpoint both products could vary greatly. Therefore, assuming any two products with the same IES classification will provide identical or even a similar light distribution pattern is a mistake. Only by looking at each product separately at the application level can such comparisons be made.
Where have LEDs been used in the lighting industry?
LEDs began to be used in the lighting industry in the late 1990’s typically in aesthetic, effect, or specialty lighting applications, including architectural highlighting. The use of LED luminaires in applications such as street lighting, area lighting, parking structures, security lighting, and even general lighting for interior spaces is viable today both economically and from an illumination performance standpoint.
Are your products compatible with emergency backup systems?
Yes, with inverter-style battery backup systems that produce true sinewave outputs.
Indoor
Are your fixtures/housings fire rated?
Fire rating depends on the housing, and currently none of our housings are fire rated. Our downlight products are designed for fire rated housings.
Are your products plenum rated?
We do not currently offer any plenum rated products.
Are your products compliant with the Trade Agreements Act (TAA)?
TAA Compliant Products
TAA refers to the Trade Agreements Act (19 U.S.C. & 2501-2581), which is intended to foster fair and open international trade. TAA requires that the U.S. Government may acquire only “US-made or designated country end products."
This act requires that contractors must certify that each end product meets the applicable requirements. End products are "those articles, materials and supplies to be acquired for public use.” This includes items which have been “substantially transformed” in the U.S.
Cree’s TAA compliant products are manufactured and/or assembled in the U.S. and are approved to be acquired by the U.S. Government for use. These products are also compliant with GSA Schedules.
The following products are only TAA compliant when the designation -US is included in the ordering number, which specifies that the product is "U.S. Manufactured."
LR6TM Family: LR6 LR6-DR650 LR6-DR1000 LR6-277V LR6-DR1000-277V
LE6
Architectural Troffers - CR Series: CR24 CR22 CR14
2' x 2' Architectural Lay-ins - LR24TM Family: LR24-32SKA35 LR24-38SKA35
Can a CFL housing be converted to LED?
If the CFL housing is pin-based with an integral housing, then no. If the CFL housing is an incandescent housing with a CFL installed in it, then refer to the Recommended Housing List for compatibility.
Are your fixtures grounded?
Our downlight and troffer products are attached directly to earth ground at installation. Our lamp products are not.
Are any of your products compatible with shallow housings?
Some of our downlight products are compatible with shallow housings.
Are your products difficult to install? Do I need special wiring, dimmers, etc.?
Our products are designed to be easy to install with no special tools or experience needed, using conventional dimmers and wiring. Please reference our installation information for detailed documentation.
Are your products Title 24 compliant?
Our products meet California and Washington state Title 24 requirements.
Are your products UL certified?
All Cree LED Lighting products are UL certified. Please visit the UL website to find more details about our certifications to UL standards.
Can any part of your products or trims be painted?
Painting, staining, or otherwise altering our products voids the warranty.
Can I use higher gauge (smaller) wiring since your products draw much less current?
Although Cree LED Lighting products run at much lower current levels than typical lighting, wiring size is determined by local code requirements and by the NEC.
What is the ceiling hole size required for your housings?
Refer to the Product Spec Sheet or Installation Instructions for the specific products.
Do you offer sloped ceiling options?
We do not currently offer downlight products designed for sloped ceilings; however, our lamp product family is compatible with most sloped ceiling housings.
Do your products change light color when dimmed?
No. All of our current products are designed to maintain light color consistent through the dimming range.
Outdoor
Are your fixtures suitable for in-ground fixtures?
At this point Cree LED Lighting doesn’t have any products for in-ground lighting applications.
How are LEDs able to outperform HID?
Super-bright white LEDs have the advantage of minimal lumen depreciation, better optical efficiency and high lumens per watt. LEDs also have a vastly longer life span than traditional lamp sources. The luminaire must be designed to leverage these inherent advantages of LEDs. A total systems approach is needed for an LED product to bring all these features together.
Cree luminaires also have an environmental advantage in that they contain no mercury, are RoHS compliant, last longer and produce less waste. In fact, 20 to 25% (by weight) of the product is made using post-consumer recycled materials (aluminum castings and extrusions). Furthermore, 70% (by weight) of Cree fixtures are readily recyclable. The remaining LED circuit boards, drivers, wires and connectors are all non-hazardous, mercury-free, and RoHS compliant.
Housing
The fixture goes up into housing, but drops back down slightly
Wedge some wooden shim material between the housing and the ceiling material to secure it firmly.
The fixture won't stay firmly in recessed housing
Extend mounting clips perpendicular (90°) from the fixture, then insert straight up into the recessed housing.Search Recommended Housing List for compatibility.
The fixture won't go far enough up into the housing
Refer to the Installation Instructions where it states to remove the adjustable socket bracket prior to installation.
Check Recommended Housing List for compatibility. If it's a shallow 6" housing, such as the Halo H27 series, the LR6-GU24 and CR6-GU24 will work, as the GU24 socket base is much shorter than an E26 Edison screw base.
Mechanical
On the H4, the hanger bars won't allow enough movement to place the fixture off-center
Remove the small brake screws from the ends of the hanger rails, allowing more movement.
Electrical
Only one switch works in 3-way configuration
Cree LED Lighting products are no different than conventional lighting loads when connected to 3-way switching circuits. Check the wiring instructions provided with the switch for proper connection.
Dimming
General guidance for dimming
Incandescent dimmers are designed for "resistive" loads, and typically rated for at least 600 watts. They have a requirement called "minimum holding current", which is the minimum amount of electrical current flowing through them to keep the dimmer firing properly.
Cree LED Lighting downlight and lamp products have electronic drivers that are "reactive" (capacitive and/or inductive) and draw very little power (10-11 watts). These two factors result in electrical current that is just barely above the minimum holding current for most dimmers, and below it for others. There are other factors specific to the installation site, such as neutral-to-ground integrity, power line noise coming from the utility or other loads, and source impedance. With the minimum holding current requirement barely being met, these other factors can cause the current to dip below that threshold, resulting in occasional dimmer mis-firing which can result in a faint flickering coming from the lights.
Cree LED Lighting tests its products with a variety of dimmers, and makes recommendations regarding compatibility based on those results, but cannot guarantee performance.
The LR4™ and LR6™ product families are designed to dim down to ~25% of full brightness, then turn off when dimmed below that. Due to the nature of LED light, this can appear more like 40%-45% when looking directly at the fixture. Examining the room being illuminated will give a more accurate perception of actual brightness.
The CR6™ and LR24™ products are designed to dim down to 5% of full brightness. Due to the repetitive peak currents generated by the inrush current of LED lighing fixtures, Cree products should be treated as a 75 watt load when sizing dimmers.
Light comes on at full brightness, but dimming range is limited
Incompatible dimmer: Check Recommended Dimmer List for compatibility
Improper wiring/connection of dimmer: Check wiring instructions with dimmer to ensure dimmer is connected properly
Too many or too few fixtures on dimming circuit: Refer to Recommended Dimmer List for minimum and maximum number of fixtures recommended per dimmer.
Dimmer "Low End Trim" is set too high: Determine if dimmer has a "Low End Trim" adjustment, and adjust it all the way down
Faulty dimmer: Replace dimmer
Faulty light fixture: Replace light fixture
Light comes on at full brightness, then turns off when dimmer is turned down
Incompatible dimmer: Check Recommended Dimmer List for compatibility
Improper wiring/connection of dimmer: Check wiring instructions with dimmer to insure dimmer is connected properly
Too many or too few fixtures on dimming circuit: Refer to Recommended Dimmer List for minimum and maximum number of fixtures recommended per dimmer.
Faulty dimmer: Replace dimmer
Faulty light fixture: Replace light fixture
Light does not come on at any dimmer setting
Incompatible dimmer: Check Recommended Dimmer List for compatibility
Improper wiring/connection of dimmer: Check wiring instructions with dimmer to insure dimmer is connected properly
Open circuit between dimmer and fixture: With dimmer fully turned up, check the voltage level at the fixture socket. It should be ~110vac.
Faulty dimmer: Replace dimmer
Faulty light fixture: Replace light fixture
Light "flickers" or "pulses" when dimmed
- Check Recommended Dimmer List for compatibility.
- Turn off adjacent loads to see if flickering stops. If it continues, noise is likely coming from outside the home or building. Replace dimmer with one that provides better noise attenuation. Cree LED Lighting recommends the Lutron Skylark SF-10P (single-pole) or SF-103P (3-way).
- Replace dimmer.
- Disconnect light fixtures one at a time to determine which one is causing the rest to flicker. Replace the faulty one.