AIA/CES Provider Number: 50111167

EE300: Lighting Control of LEDs, Part 2: Wired Control of LED Lighting

Course Number: 000000003002

Educator: Kevin Willmorth

 

EDUCATION CREDIT

At the end of this course, participants will be able to complete an online exam, with a passing grade of 70+% to qualify for LEU (NCQLP) credit and 

80+% for LU/HSW hours (AIA/CES). Upon a passing grade, you will be able to download a Certificate of Completion for each type of credits. For LC

certification maintenance (LEUs), credits are self-reported. For AIA /CES, Lighting Controls Association will report credit earned for this course to AIA

CES.

NO ENDORSEMENT BY ACCREDITING ORGANIZATIONS

This course is registered with NCQLP and AIA CES for continuing professional education. As such, it does not include content that may be deemed

or construed to be an approval or endorsement by these organizations of any material of construction or any method or manner of handling, using,

distributing, or dealing in any material or product.

 

COPYRIGHT

This presentation is protected by US and International copyright laws. Reproduction, distribution, display and use of the presentation without written

permission of the Lighting Controls Association is prohibited.

DISCLAIMER

The information contained in this course has been obtained from sources believed to be reliable. Damages arising from errors, omissions or damages

as a result of the use or misuse of the data or information contained in this course are not the responsibility of the Lighting Controls Association,

National Electrical Manufacturers Association, ZING Communications, Inc., Lumenique, LLC or their employees or members. All information

contained in this course is published for professionals seeking information about the subjects contained therein. It is not the intent of this course

provide professional services such as design, engineering or consulting. If these services are sought, they should be rendered by properly trained,

registered, regulated and insured professionals.

 

COURSE DESCRIPTION

This course provides a working understanding of control

methods for LED lighting products and how to integrate these methods into modern lighting design.

White-light LEDs offer the potential of energy savings and long service life. The good news is that with few exceptions, control of most white-light LED

products is possible using existing control system architecture, including dimming and remote-sensing applications.

In Part 2 of this course, the dynamics of wired control of LED lighting is explored, including automatic white light shifting and lumen maintenance

features.

Image courtesy of Cree, Inc.

LEARNING OBJECTIVES

At the end of the course, participants will be able to:

Identify controls appropriate for various LED lighting applications

Generally match equipment, control method and protocol to equipment and applications

Identify opportunities for utilizing automatic lumen management control

Understand the range of standards applicable to wired controls used in lighting applications

LED DRIVERS AND POWER SUPPLIES

Most LED products require devices to condition incoming power and

control the energy flow passing through the LEDs within, including converting incoming power from AC to DC. LED drivers control power flowing

through the LED product by either maintaining a constant voltage or constant current. Power supplies may be integrated into the driver or mounted

separately.

As there are no special demands made by LED products that require special switching control, switching and relay-based control of LEDs can be

effected the same as with fluorescent loads.

For dimming, it is important to note that not all LED products can be dimmed. Special LED drivers and power supplies are required; the product must

be rated as dimmable.

There are several methods for achieving dimming, including phase cut power line side control, separate line voltage control and low voltage control in

either analog or digital forms. Achieving satisfactory results requires matching the type of control with the driver and/or power supply components.

Image courtesy of Lutron Electronics

2-WIRE LINE-VOLTAGE DIMMING

The simplest control system is 2-wire line-voltage dimming. This refers to any control placed on the power line feeding an LED product, usually 120V

AC. Products designed for line-voltage control use either standard wall-box dimmers or remote dimmer modules designed for line-voltage

incandescent, magnetic and electronic low-voltage incandescent, or line-voltage dimmable fluorescent loads. Due to large variations in dimmer

characteristics and LED driver system designs, compatibility of line-voltage controls and driver system are not universally assured.

Image courtesy of Lumenique

PHASE-CUT TRIAC (FORWARD OR LEADING EDGE) DIMMING

Wall-box dimmers control current flow to connected loads by modifying the sine wave using one of two approaches. The most common incandescent

dimmer design is called a triode for alternate current, or TRIAC, design. This is simple low-cost design that switches power OFF at the leading edge

of the sine wave for a period of time and then switches it back ON, producing a sudden voltage jump from zero to whatever the line voltage is at the

end of the dim cycle time.

This abrupt change, and switching the load ON and OFF, will disrupt the proper operation of LED driver and power supplies not designed to function

on TRIAC-dimmed circuits.

Image courtesy of Lumenique

PHASE-CUT MOSFET (TRAILING EDGE) DIMMING

Through use of specialized transistors and small logic processors, trailing-edge dimmers maintain the leading edge of the sine wave, ramping voltage

up from zero and eliminating the abrupt surges that occur with TRIAC-based dimming. This circuit design was developed to control electronic loads,

improving power supply performance and reducing electromagnetic interference (EMI).

Using these dimmers to control LED systems, however, requires special circuiting within the LED power supply and/or driver to accommodate input

power fluctuations.

UNIVERSAL WALLBOX AND PORTABLE DIMMER CONTROLS

To address some of the issues of retrofit lamps and mixed sources in spaces requiring dimming, new generations of dimmers have been introduced.

These dimmers are designed to operate dimmable compact fluorescent and LED products as well as halogen and incandescent. Specialized circuitry

and filtering inside these dimmers produce better control operation and fewer EMI issues.

Images courtesy of Lutron Electronics

RETROFIT LED PRODUCTS WITH INTEGRATED DRIVER CIRCUITS

LED retrofit lamps that operate on standard dimmers are an excellent upgrade to

bring the energy savings of LEDs into lighting systems with existing controls. In applications with existing dimmers, look for compatible retrofit

products designed to operate with them. These products use special circuitry to maintain proper function with dimmers. Note, however, that not all

lamps designed to operate on conventional dimmers will work with all dimmer products. To ensure the controls in use and the selected retrofit lamp

are compatible, consult the manufacturers.

Images courtesy of Cree, Lighting Science Group and Lutron Electronics

STANDARDIZATION OF FORWARD PHASE-CUT DIMMING

NEMA’s standard, SSL 7A-2013, Phase-Cut Dimming for Solid-State

Lighting: Basic Compatibility, was developed to address compatibility between lamps, luminaires and forward phase-cut wallbox dimming controls.

Products labeled as 7A or SSL 7A compliant are intended to be universally compatible. Zhaga specifications incorporate SSL 7A.

Image courtesy of the U.S. Department of Energy

AUTOMATIC CONTROL

The majority of energy-saving applications for lighting

control involves use of automatic lighting controls. LEDs are not adversely affected by frequent switching or dimmed operation. In applications where

line-voltage control is used, there is nothing inherent to LED lighting that precludes it being controlled in the same manner as any other light source.

Occupancy sensors, photocontrols, remote switching and connection to building power management systems remain very similar to fluorescent or

incandescent controls.

CONTROL METHODS AND PROTOCOLS: 3-WIRE LINE-VOLTAGE DIMMING

Three-wire line-voltage dimming, developed for fluorescent dimming, involves a third line-voltage dimmed control wire. Products designed for 3-wire

line-voltage control use either wallbox dimmers or remote dimmer modules. Since power supplied to the LED driver is maintained at full power, with

control signal provided separately, issues of dimming range and product compatibility are significantly reduced over simple line-voltage wallbox

dimming controls.

Image courtesy of Lumenique

CONTROL METHODS AND PROTOCOLS: 0-10V

0-10V control establishes a consistent Class 2 wiring interface that is light source agnostic. All connected luminaires include a logic circuit that

interprets their total dimming range from lowest to highest, within the common range of 0V to 10V. For LED systems that incorporate power supplies

and drivers to maintain constant current or constant voltage to the LED sources, the use of 0-10V control is the most universally available dimming

capability. This allows the use of the already well established system components used for fluorescent lighting, and is fully compatible in mixed

source applications. The only requirement is to utilize a separate control for each luminaire type, never mixing sources on one control. This applies to

mixing LED products as well as mixing LEDs with other sources.

Images courtesy of Lumenique and Lutron Electronics

CONTROL METHODS AND PROTOCOLS:  PHOTOSENSOR 0-10V DIMMING CONTROL

This type of control provides proportional luminaire output based on the input or received ambient light from a 0-10V sensor. The chart below depicts

the linear characteristics from a 0-10V photosensor that is linked to an LED dimming driver. A typical 0-10V sensor will need to be connected or

linked to a controller that will convert the sensor output into the appropriate driver voltage via the control algorithm.

Image courtesy of PLC Multipoint

CONTROL METHODS AND PROTOCOLS:  PHOTOSENSOR 0-10v SWITCHING CONTROL

A typical 0-10V or 1-10V photosensor can also be connected to a controller that has been programmed to provide daylight ON/OFF switching control

as depicted in the graphic below.

Image courtesy of PLC Multipoint

CONTROL METHODS AND PROTOCOLS: DMX

DMX512A is based on a Class 2 RS485 serial bus that uses XLR Style 5

pin connectors (basic F+DMX requires only three of these) or Cat 5 Ethernet cabling with 8P8C connectors (similar to RJ45). The bus speed is

relatively slow at a rate of 250 kbaud. Luminaires are connected in a series daisy chain with a termination resistor installed on the last luminaire.

Each connected luminaire is assigned a unique three-digit address either by 1) software based on location in the daisy chain, DIP switches or dials in

the luminaire, or 2) an electronic addressing module in the luminaire or in the system. The software will allow grouping to respond to identical

settings. While no two luminaires share the same address, they may be grouped as a single load outside the DMX universe and assigned to a

dimmer that is part of it.

Image courtesy of Lightronics

CONTROL METHODS AND PROTOCOLS: RS485

RS485 is a standard for balanced data multipoint communications, commonly

accomplished over three-, four- or five-wire cabling systems. The most common is used with the DMX512A controls protocol. Standard pin-out

connections assure installations comprised of several manufacturers’ products remain compatible.

CONTROL METHODS AND PROTOCOLS: ART-NET

Art-Net, a trademark of Artistic License Holdings, Ltd., is an open source protocol based on TCP/IP that allows transfer of large amounts of DMX512

data over wide-area wireless networks. The protocol uses universal addressing and supports more than 4,000 universes when operated on

1000BaseT Unicast networks or 40 universes on broadcast networks.

Image courtesy of Lumenique

CONTROLS PROTOCOLS: SMART CONTROL TECHNOLOGIES

The term “Smart Control” applies to a growing range of lighting or whole-building controls approaches that include two-way communications, a

network of controlled loads (lighting and other building systems), and various input components, such as sensors, time-clocks, user-activated controls

and system feedback loops from loads and power sources. All of the system components are connected through a computerized interface that

monitors input channels and feedback from active systems, to control loads to achieve a desired end result.

Smart controls may be wired system based, wireless or a combination of both. While there are no specific limits on how a smart controls system is

built, the common requirement is that all components be compatible to one another in order to facilitate the necessary uniform level of control and

intelligence processing.

Image courtesy of Lumenique

CONTROL METHODS AND PROTOCOLS: DALI

The Digital Addressable Lighting Interface, or DALI, is a standard lighting control protocol. As with DMX, each luminaire is assigned a unique address

and responds to data signals distributed through a common communication line. DALI further offers two-way communication capability, enabling

control systems to feed energy and maintenance information to a centralized point for analysis. Controls may be added anywhere along the low-

voltage communication bus.

Images courtesy of Lumenique, Philips Lighting and Creative Lighting

LOW-VOLTAGE LED CONTROL CONNECTION POINTS

The control wiring may not be to the luminaire location. In many cases, LED products utilize remote power supplies and power supply/driver

combinations. In every case, wiring of the control will always be to where the driver electronics are located.

Image courtesy of Lumenique

AUTOMATIC WHITE LIGHT COLOR SHIFT: DIM TO WARM

LEDs do not shift in color to a warmer color when dimmed like incandescent

lamps. For applications where the this effect is desirable to support a desired mood, without adding the complexity of color mixing controls, a growing

number of LED products are becoming available to deliver this effect automatically in response to dimmer setting.

This dim-to-warm effect is attained through mixing of different LED sources, driven by internal drivers, programmed to deliver a warmer color tone as

the light output is reduced.

Image courtesy of Cree

AUTOMATIC LUMEN MAINTENANCE CONTROL

In a conventional lighting system, light loss factors, including lumen depreciation, are added to the desired maintained light level. This results in initial

over-lighting that slowly declines to the target illuminance level as the system ages. The result is wasted energy and continually declining illuminance

levels.

By starting a system at a reduced energy level, then ramping up drive current over time using automatic or pre-programmed regulation that increases

power to the LEDs as the system ages, constant light output is maintained over most of the life of the LED product. Additionally, energy is saved and

service life is extended.

Outward appearance and photometric performance of luminaires featuring lumen management control is unchanged.

Images courtesy of Lumenique

ETHERNET POWER AND CONTROL BACKBONE: REDWOOD SYSTEMS APPROACH

Redwood Systems is a unique platform based on line-voltage conversion to constant-current low-voltage DC at a central location, similar to the layout

of a computer network server room. Luminaires, sensors and controls are connected to the power supply/driver engines using standard Cat5e

cabling. The application network is open, enabling customers and system partners to integrate Application Programming Interface (API) and

BACnet/IP protocols. The system is modular, with each central engine capable of powering 64 channels at 500mA, 20W per channel, 12-55VDC.

Luminaires produced with the appropriate RJ45 cable connectors and configured for connection to the Redwood Systems infrastructure are labeled

as “Redwood Ready.” Note that these RJ45 connected devices are not compatible in any way with DMX 512A products using the same connectors.

Image courtesy of Redwood Systems

CONTROL METHODS AND PROTOCOLS: BACNET

The Building Automation and Control Network (BACnet) is an open whole-building “smart” automation communication protocol developed by

ASHRAE. BACnet devices send and receive service messages that can be communicated over wired Ethernet, ARCNET and MS/TOP (master-

slave/token passing) LAN networks. BACnet can also include wireless connections by pairing it to other protocols such as ZigBee. BACnet addresses

building automation as a whole, encompassing lighting within a larger envelope of control needs including HVAC, security and building utility

operations.

Image courtesy of BACnet.org

CONTROL METHODS AND PROTOCOLS:  NTCIP 1213

The National Transportation Communications for ITS Protocol (NTCIP), published jointly by the American Association of State Highway and

Transportation Officials (AASHTO), the Institute of Transportation Engineers (ITE), and the National Electrical Manufacturers Association (NEMA), is

a series of documents addressing standards for communications protocols for transportation applications. NTCIP 1213 specifically addresses

Electrical and Lighting Management Systems (ELMS) protocols for two-way communications between automatic and manual control devices, data

collection centers and luminaires used in transportation applications. This standard includes both wired and wireless control protocols under a

uniform set of specifications specifically tailored to the transportation industry.

Image courtesy of the U.S. Department of Transportation

YOU’RE FINISHED

This concludes The American Institute of Architects Continuing Education Systems Course EE300: Lighting Control of LEDs, Part 2: Wired Control of

LED Lighting. You are now ready to take Part 3: Wireless Control of LED Lighting.

Please take a moment to provide feedback about your experience with this course.

You may also take the Comprehension Test to test your learning and to qualify for LEU (NCQLP LC) and LU/HSW (AIA CES) credit. A 70+% passing

grade is required for LEU credit and 80+% for AIA CES credit. Upon passing the test, you may download a Certificate of Completion on the Courses

page. If you are an AIA member, please email your course completion certificate to LCA with your AIA number.

 

EE300: Lighting Control of LEDs, Part 2: Wired Control of LED Lighting Quiz