PoE-powered lighting approaches and considerations

The technology holds promise for cabling-system installers and managers. Like other emerging technologies, it requires planning and consideration.

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The technology holds promise for cabling-system installers and managers. Like other emerging technologies, it requires planning and consideration.

Power over Ethernet (PoE) or remote-powered lighting is a technology that, by many accounts, holds significant promise for professionals who specify, design, install, or manage communications cabling systems. It is a current example of a building system that can operate over the type of wiring typically used to support data transmission. Additionally, in many cases an intelligent lighting system can operate on less energy than a traditional lighting system in the same building space.

On Berk-Tek’s website, the company explains, “More and more organizations are seeing the cost savings and efficiency benefits of converging their building automation systems onto their IP [Internet Protocol] networks. Smart lighting is one area of building automation that is growing rapidly and will quickly become the preferred technology for lighting in schools, hospitals and other enterprise facilities. It offers greater control over building automation applications, is cost/energy efficient, and provides an improved user experience.

“LED lighting solutions have been used within the enterprise space for quite some time,” Berk-Tek continues. “There are numerous advantages to incorporating your lighting system into your IP networks [including that doing so] can provide you with actionable data to improve the efficiency of your business. For example, based on analytics gleaned from your smart lighting system, you could reconfigure your floor space to improve your space utilization from 80 percent to 90 percent.”

Bright horizon

A cynic’s definition of a “promising technology” may be one that hasn’t yet amounted to very much. As of mid-2018, that definition could apply to intelligent PoE-powered lighting. “There are reasons PoE lighting adoption has been slow—by some reports only about 2 percent in the United States,” explained Transition Networks product manager GlenNiece Kutsch. “Control systems have been proprietary, not interoperable, costly, and complex to install and reconfigure.” Despite that, she emphasized, there are reasons to believe that technological improvements will lead to wider adoption. “The cost and performance of LED lighting itself has been gradually improving, so that’s one thing that will allow us to see improved adoption in the future,” she said. Furthermore, she added, “improvements in PoE as well as PoE++ will open the door to cover more of the LED lighting that exists.”

As of the time of this writing, the completion of the IEEE’s 802.3bt specification was imminent—on track for September 2018. That specification will introduce higher standardized levels of power distribution via twisted-pair cabling. Kutsch noted that the power levels specified in the 802.3at standard covered approximately 20 to 25 percent of LED luminaires available in the market. “The 802.3bt specifications should cover about 70 percent or so of luminaires.”

If a cabling contractor is proposing a PoE-based lighting system to an end-user customer or is preparing to carry out such an install, the system’s design and layout are essential to the project’s success. In the technical document “Zone Cabling and Coverage Area Planning Guide: 60W PoE Lighting Applications,” Siemon points out that it “recommends that PoE lighting device coverage areas be planned to have a radius no greater than 13 meters (43 feet) to optimize the number of cables (i.e. more than 96 cables becomes difficult to manage) needed to support the typical density of PoE lighting devices in this space and to align with other zone cabling systems supporting fifth-generation (IEEE 802.11ac) and future WiFi applications. This practical guidance also simplifies the design task of overlaying the zone cabling system supporting building automation and other IP devices with the zone cabling system supporting PoE lighting devices.

“Although multiple coverage areas may be arranged in a variety of patterns throughout a building space (e.g. hexagon-shaped, grid-shaped or leg-shaped), a grid-based pattern most easily supports a PoE lighting system deployment because luminaires are typically arranged in a grid-based fashion. In this case, a coverage area with a 13-meter radius translates to an 18-meter-by-18-meter [60-foot-by-60-foot] grid. Multiple coverage areas may be arranged throughout the building space to support PoE lighting connections and devices as needed. Unless the telecommunications room (TR) has limited accessibility, coverage areas that are in close proximity to the TR can be connected directly to the floor distributor without passing through a service concentration point. For optimized design efficiency, Siemon recommends that zone enclosures be positioned at least 30 meters from the TR.”

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Transition Networks’ 24-port managed PoE++ switch line supplies up to 90 watts of power per port for applications like PoE lighting. Features like device-management software and autodiscovery can be beneficial to installers and users of PoE lighting systems.

More design considerations

Panduit’s manager of network architecture, Brian Kelly, authored the paper “PoE Lighting Benefits and Design Considerations,” in which he also addresses a zone-cabling architecture’s ability to support this application. “Zone cabling is a standards-based structured cabling strategy where all system networks are converged within common pathways from the TR to consolidation points,” Kelly explains. “This strategy is well-positioned to enable PoE lightingdeployments.”

Within that paper, Kelly also addresses other cabling-architectural considerations, including whether PoE switches should be centralized or distributed. He says, “The most common strategy is a centralized deployment, where the PoE switches are centrally located in the TR. From the TR, copper cable runs to a patch panel within the zone enclosure, then from the patch panel to the lighting troffers.

“The distributed strategy results from newer, smaller PoE switches designed for a distributed architecture. The PoE switch is in a zone enclosure, usually in the ceiling, closer to the lighting troffers. This allows for lighting troffers to be at a greater distance from the TR and uses less cable. The uplink from the TR to zone enclosure box can be fiber or copper. Fiber connections allow for greater distance.”

Transition Networks offers a portfolio of PoE switches for applications like lighting. Kutsch pointed to the company’s Smart Managed PoE+ and the more-recently introduced Smart Managed PoE++ switches, emphasizing the switches’ “embedded device-management software. The switches have features including PoE scheduling,” she explained, “which allows users to set up timeframes for devices that only need power during certain hours. The switches also report the power being used by the attached devices, which makes energy-consumption reporting easier.”

Another of the switches’ features is the ability to autodiscover and remotely configure powered devices. They offer topology, floorplan, and Google Maps views. These capabilities are useful for cabling installers as well as cabling-system end users, Transition Networks points out, because they essentially provide as-built drawings. “You can input a floorplan and drag-and-drop powered devices onto that floorplan,” Kutsch pointed out.”

Like other switches from Transition Networks, the Smart Managed PoE series devices offer Auto Power Reset, which monitors and when necessary, automatically restarts edge devices. This saves network administrators from having to manually restart such devices.

Another type of convergence

Additionally, Kelly considers converged versus separate building automation and lighting networks, noting that converging the enterprise local area network into the building automation and lighting network is not suggested. “Traditionally building automation networks have been operated by a separate, dedicated network,” he explains. “Building automation networks have also tended to be controlled by facilities/operations teams with little to no IT involvement in the day-to-day operations of the network. With the introduction of PoE lighting, some of these traditional arrangements must transform to better accommodate the requirements that PoE lighting can apply to a network.

“Building automation networks provide services such as access control, security cameras, and environmental sensors. Whether to converge these services with the lighting network is a choice that must occur prior to installing the PoE lighting network.

“Several requirements must be met to successfully converge a building automation and PoE lighting network. First, all building automation components must be IP-based or can be connected to an IP network through an adapter or converter. Second, the installed network cabling must be capable of handling PoE (generally 28 AWG to 22 AWG twisted pair copper cabling). Finally, to gain the full value of a converged building automation and PoE lighting network, a single pane of glass management software package would be required.”

Siemon concludes its planning guide by advising, “There are a number of large variables that must be considered prior to identifying the PoE lighting system that is best suited for a particular building environment, and the process to design and deploy lighting devices and balanced twisted-pair cabling in coverage areas can be complex and confusing. As a result, Siemon recommends the use of a digital lighting partner to provide assistance in designing and installing the low-voltage cabling systems for PoE lightingdeployments.”

As PoE lighting’s promise begins to be fulfilled, planning and technical considerations will increase the likelihood of success.u

Patrick McLaughlin is our chief editor.

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