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What does “Dimmable” mean  in the LED world?

Organized by: Organized by:

As Presented By: Eric Lind, Lutron 5 March 16th, 2011 2011 LEDucation 5   – March 16 New York, NY


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What does “dimmable” mean in the LED world?

Eric Lind Lutron Electronics Co., Inc


1 2 3 4 5

Dictionary Terms Expectations LED Technology and Control Options Technical Concerns The Energy Story and Next Steps

1 Dictionary Terms Orientate Conversate Dimmable Redolent ‘suggestive;’ at best, that is what dimmable infers

1 Dictionary Terms None of us recommend lamps that are

‘bright’ None of us recommend fixtures that provide

‘more than a few lumens’ We cannot afford to use the equally wishy-washy term that no one understands of


‘Dictionary’ Terms Proposed LED Labeling System (SSL Quality Advocates)

Missing: 1. Dimming Performance 2. Rated Life

2 Customer Expectations Incandescent lamp performance: • Color temperature • CRI > 90 • Light output controlled easily through voltage reduction Incandescent dimming performance: • Smooth and continuous to < 0.1% • No flicker or shimmer • No pop-on • No drop-out • No dead travel • Use of standard controls: $3 - 200 6

Dimming Expectations • We can dim – And have been for 80+ years (autotransformers)

• We should dim, independent of source – energy savings and efficiency (ASHRAE 90.1 – 2010) – space flexibility; ability to change the light level based on the activity – ambiance; dining vs cleanup – productivity; different light levels for different people (age, preference) – safety and comfort; is it better to enter a dark space or a space at 5%? – extended system life

Dimming Expectations Control Factors: ASHRAE 90.1-2010 draft • Manual, continuous dimming control or programmable multi-level dimming control


• Programmable multi-level dimming control using programmable time scheduling


• Multi-level occupancy sensors


• Automatic continuous daylight dimming


Dimming Expectations Measured vs perceived light: • Measured light: the amount of light as shown on a light meter • Perceived light: the amount of light that your eye interprets due to dilation • 20% measured = 45% perceived


The Challenge

(and the opportunity)

In order for LEDs to take the place of existing light sources, they need to be controllable â&#x20AC;&#x201C; with details.


3 LED Technology and Control Options LED Lamp:

LED Fixture:


LED Control Options Line voltage control: • Forward Phase control – Incandescent and magnetic low voltage (MLV) dimmers

• Reverse Phase control – Electronic low voltage (ELV) dimmers

• 3-wire control – Fluorescent (F) dimmers

• Power-line carrier

Low voltage control: • • • •

0-10V Digital (DALI, EcoSystem®) DMX-512 DC 12

LED Control â&#x20AC;&#x201C; Phase control Forward Phase Pro: Largest installed base Con: Hit or miss performance with LEDs

Reverse Phase Pro: Typically performs better than forward phase Con: More expensive than forward phase and requires neutral wire 13

LED Control: Low voltage analog 0-10V Standard: IEC 60929 Annex E-1 Pro: Industry standard control type Con: Poor performance with line noise and long wire runs


LED Control: Low voltage digital DALI Standard: IEC 62386-101, -102, -201, -202, ... Pro: Individual addressing of fixtures and flexible control wiring Con: System startup and programming required, slow response time if sequences or color changing is required 15

LED Control: Low voltage digital DMX-512 Standard: USITT 512-A Pro: Color mixing and varying color intensity, fast time response Con: More complex wiring and integration for general illumination


LED Control - Performance Questions •

What is the dimming range?

Does this performance include any of the following: • • • • • •

Flicker Pop-on Drop-out Audible noise (not EMI) Dead travel Long start times (>2 seconds)

Will you see color shift?

What is the THD for the lamp or fixture?

What is the rated life?

4 Technical Concerns • Current inrush spikes can cause the LED lamp to appear like a much higher wattage product to the dimmer • Applying too many LED loads to a dimmer may cause the dimmer to fail prematurely or trip the circuit breaker, even if the dimmer or circuit rating has not been exceeded! • Maximum number cannot be determined by “dimmer’s capacity and the fixture’s rated wattage” • Ask your controls manufacturer.

Inrush Current (@ turn on)

Inrush Current – INC vs LED

Technical Issues Still Being Evaluated • Electromagnetic Interference (EMI) or Radio Frequency Interference (RFI) – For fixtures with dedicated drivers and LED modules, pulse width modulation vs constant current reduction

• Arc-Fault Breakers tripping (independent of previously mentioned overload condition)

5 The Energy Story and Next Steps “We will not need to dim LED lighting because we will be saving so much energy.” - Anonymous “The success of our industry has created a behavioral script that we expect the downlights overhead to dim.” - Mark Lien (paraphrase of August 2010 LD+A article) “The test of a first-rate intelligence is the ability to hold two opposed ideas in mind at the same time and still retain the ability to function.” - F. Scott Fitzgerald 22

The Energy Story Power vs. Measured Power Usage vsUsage Measured Light forLight an LED Fixture for Lutron LED drivers

(example shown is a fixture with a dedicated LED Driver)



80% 60% 40% 20% 0% 0%






Measured Light 23

Next steps Standards emerging: • NEMA dimming white paper (standard in process)

What to do now: • • • •

Mock-up, mock-up, and mock-up Use products from companies that you trust Consult published control compatibility information Ask LED product manufacturers the following questions before purchasing their product (next slide) 24

Next steps LED product manufacturer checklist: 1. 2.

What is the dimming range of the product? What type of dimmer does the product operate on? • Forward phase control • Reverse phase control • 0-10V • DALI • DMX-512 3. Is the dimming range smooth and continuous? Is the light level stable at every dimmed level or are there points of flicker? Is the color consistent throughout the dimming range? Is the performance consistent with one lamp/fixture per dimmer and two or more fixtures per dimmer? 4. What is the minimum and maximum number of fixtures/lamps that can be used on a dimmer or control system? 5. Have they tested multiple dimmers/control system of the same type from multiple manufacturers?


Thank you

Eric Lind Lutron Electronics Co., Inc


What Does "Dimmable" Mean in the LED World?