Fundamentals of connected lighting control systems
The combination of LED technology and intelligent lighting control systems has significantly lowered energy usage while simultaneously reducing operating expenses.
February 26, 2018 — Smart lighting delivers more than just illumination: the combination of LED technology and intelligent lighting control systems has significantly lowered energy usage while simultaneously reducing operating expenses and addressing ever-tightening building code requirements.
According to a July 2017 report published by the U.S. Department of Energy, “even though connected lighting controls were installed in less than 0.1% of all U.S. lighting systems in 2016, this technology is pivotal to maximizing future potential energy savings”. It’s clear we are at the early stages of a major industry shift, and the benefits have not been fully realized yet.
In addition to energy usage and code compliance, lighting control systems support a work environment sought by millennials, the incoming generation of employees. Millennials are looking for a different work environment than previous generations. They are knowledgeable and comfortable with technology, and expect mobility, modern tools and data to be available at their fingertips.
According to research from The Brookings Institution,1 millennials are expected to become 50% of the global workforce by 2020 and 75% by 2025. Progressive firms are creating more informal, communal and flexible work environments to attract and retain this demographic, and connected lighting control systems are playing a major role in defining these workspaces.
The role of LED technology in connected lighting
Technology has transformed the lighting industry. LED lights are up to 80% more efficient than traditional incandescent or fluorescent lamps, and have a much longer life. Potentially more important, this technology enables lighting to become part of the digital world. It is a natural partner to sensors and digital networks and, when partnered with an intelligent lighting control system, turns everyday lights into smart, connected devices.
By connecting each light point on a digital network, lighting can be centrally managed. Using information from sensors, smart lighting control systems are able to automatically adjust light to appropriate levels based on conditions such as occupancy or daylight availability. This saves on energy usage and contributes to comfort levels in the workplace.
Before leveraging a connected lighting control system, it is important to understand the different system types, architectures and network control protocols.
Stand-alone versus networked systems
There are two types of connected lighting control systems: stand-alone and networked. At a fundamental level, both are controllable systems that meet energy codes and offer significant energy savings. Choosing the best system depends heavily on the level of features and functionality needed, business strategy and requirements, allocated support resources, space size and whether an internet connection is required.
Stand-alone systems are best for small- to mid-sized spaces and offer the benefit of simple features with easy-to-use controls and require minimal installation and setup resources. These systems focus on energy savings and meeting code compliance and often can be connected to numerous systems for multi-system management.
One of the primary benefits of a networked system is that it can be managed remotely or by a third party. These systems offer advanced features and functionality, primarily for enterprises and larger spaces. While experienced specification, installation and commissioning resources are required, the focus of networked systems goes beyond energy savings and code compliance to include sophisticated offerings, like data analytics and advanced energy reporting features. Networked systems also allow for building automation system integration.
System architecture: wired, wireless or hybrid
Lighting control systems can be wired or wireless, or a combination of the two (hybrid). These terms refer to how control signals are communicated, not how a control device or luminaire receives power.
In a typical wired lighting control system, control signals are sent using communication wires whereas, in a wireless system, control devices communicate through the air using radio-frequency (RF) waves.
Hybrid solutions are implemented when one part of the building is wired and other parts are not. Wireless lighting control becomes an extension of the wired lighting network to provide coverage in hard-to-reach areas that cannot be wired.
Choosing a network control protocol
Network protocols define rules and conventions for communication between network devices, and are classified as proprietary or open.
Proprietary protocols are usually developed by a single vendor for the devices they manufacture. Other vendors may or may not support the proprietary protocol, so special gateway equipment likely will be required in multi-vendor environments. Open or standard protocols are agreed upon and accepted by the industry, and are not vendor-specific. Standard protocols often are developed by a collaborative effort of experts from different organizations.
Wireless control protocols include ZigBee, Bluetooth Low Energy (BLE), EnOcean and Wi-Fi.
• ZigBee is a standard protocol defined by the IEEE standards body. It was designed to be a low-power, low-data-rate, proximity wireless mesh network protocol, with the intention of being simpler and less expensive than other wireless network protocols such as Bluetooth or Wi-Fi. It offers a high level of security with 128-bit encryption.
• BLE offers 1-Mbps bandwidth and a range of up to 100 metres. The key advantages include consumer familiarity, a widely established ecosystem and a multi-vendor supply chain. Although it is considered a standard protocol, BLE is not open, as it must be licensed from the Bluetooth Special Interest Group.
• EnOcean is a standard that uses energy harvesting to power sensors and switches to operate without batteries or a wired energy source. Although it is considered a standard protocol, it is not open, as it must be licensed from EnOcean.
• Wi-Fi provides a higher bandwidth capacity than ZigBee, Bluetooth or EnOcean, but is typically more expensive and consumes more power than the alternatives.
Wired control protocols include 0-10V, DALI (digital addressable lighting interface), GreenBus II and Digital Multiplex (DMX).
• 0-10V is a standard analogue control protocol. It applies a DC voltage signal from <0V (minimum light output 0%; control wires short-circuited) to 10V (maximum light output 100%; control wires open) to produce a varying intensity level. Since the current through the LED remains unchanged, there is no colour shift at different dimming levels. 0-10V protocols are typically used for ballasts and LED power supplies to control dimming functions, where the dimming range of the power supply or ballast is limited.
• DALI is a non-proprietary, bi-directional protocol specified by international technical standard IEC 62386. It provides a single interface for all light sources and lighting control devices. This protocol not only permits devices to be individually addressed, but also allows multiple devices to be addressed simultaneously via multicast and broadcast messages. The DALI protocol can be used for communications and control of lighting equipment; not just ballasts, but also LED drivers, switching devices, emergency inverters, colour control, etc.
• GreenBus II is a DALI-based proprietary control protocol developed by Osram for connecting devices to the Osram Encelium networked light management system.
• DMX is a digital control protocol that can be used for a variety of devices to control options such as light levels, focus, light colour or rotation of lights. In a standard configuration, DMX control interfaces can provide up to 512 addresses, are programmable via software and/or mixing desks, and are suitable for complex lighting scene sequences. DMX is typically used for stage lighting and theatrical effects, but also can be used to control colour-changing LED applications.
The future of connected lighting
Choosing a smart lighting solution and understanding terminology,protocols, architectures and more can seem overwhelming. However, fully understanding the options available and examining the benefits they bring to a given installation will make all the difference as the world moves toward
smart connected lighting.
With benefits like significantly reduced energy consumption and related operating expenses—along with increased employee productivity, workplace satisfaction and improved occupant health and wellness — smart connected lighting is here to stay. Examining the unique space and occupant requirements, and identifying potential partners for a given project, will enable a seamless transition to a connected lighting control system.
1. “Brookings Data Now: 75% of 2025 workforce will be millennials,” Fred Dews, July 17, 2014, tinyurl.com/yab6euck.
Chuck Piccirillo is Head of Product, Lighting Network & Solutions, Osram Digital Systems, and is a lighting certified (LC) professional. He holds a Bachelor’s degree in Chemical Engineering from Clarkson University and an
MBA from Northeastern University.
This article originally appeared in the February 2018 issue of Electrical Business Magazine.
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