PoE Technology to Revolutionize the Next Iteration of LED Lighting Systems|
Article - August 28, 2017 By LarsonElectronics.com
PoE Technology to Revolutionize the Next Iteration of LED Lighting Systems
In the past decade, LED adoption has increased rapidly, along with the rise of the Internet-of-Things (IoT). For individuals who aren’t familiar with IoT trends, the most important thing to understand is that the two (IoT and LEDs) are closely related to each other.
Most smart gadgets on the market today use some LED diodes to enhance visual notifications, using blinking lights or colorful arrays. LEDs are suitable for such applications due to their compact and energy efficient builds. But going beyond notifications, LEDs are capable of operating via Power-over-Ethernet (PoE) technology – the same method used to power low-powered electronics – facilitated by a CAT3 to CAT7 Ethernet cable.
IEEE 802.3af and 802.at
LEDs are perfect candidates for PoE technology. The units are low voltage and capable of operating on DC power without a noticeable decrease in performance. During operation, an average LED lighting system that consumes 10 watts of power could easily run on the 802.3af PoE standard, capable of supporting up to 15.4 watts of power, or 802.3at, which can handle up to 25.4 watts of power (also compatible with 802.3af – not designed as a replacement). In the future, the IEEE 802.3bt standard will allow up to 90 watts of power, extending its applications to a wider range of LED lighting systems.
It is important to consider that the category of the cable used is critical to maximizing performance. A CAT3 cable (or better) is needed to get the most out of IEEE 802.3af (over a 44V DC to 57V DC range); while CAT5 (or better) cabling is required for yielding the benefits of IEEE 802.3at (over a 50V DC to 57V DC range).
Configurations and Benefits
In a typical PoE-powered LED lighting system, the fixture is connected to a compatible unit that is capable of facilitating PoE, such as an injector (also known as a midspan), which feeds power into the network cable. This component is found near the other core pieces of the system, such as the modem and mainstream power source (outlet). Some modern network switches already have this feature baked into the system, allowing operators to forego the need to install an external PoE injector. In such configurations, low voltage DC power is fed through the Ethernet cable, which also facilitates the transmission of data.
The advantages of using PoE to power LED lights are numerous. First, less wiring is required during installations. As a result, less time and funds are needed to complete installations. Without the limitations of wiring, PoE systems can reach sections of the building without adequate access to power. This also makes installation in such places easier, allowing flexibility in catering to different types of mounting configurations
With power and data managed through a single source, the number of critical points of failure is decreased, improving productivity and reliability. This benefit played a vital role in the performance of PoE-powered lighting systems during Super Bowl XLVII. A power outage that took out elevators, monitors and kiosks for up to 35 minutes did not affect the stadium’s Wi-Fi network and PoE-powered fixtures connected to the network because the system was running on an emergency battery.
Next, PoE-powered LEDs are safer to use. Low voltage DC power that is being utilized by a network is less hazardous to work with and around, compared to mainstream AC power from an outlet.
For operators, PoE connections are essential to smart networks. They make controlling, measuring and monitoring LEDs easier, with the use of a robust sensor or communication module. A smart LED fixture would be able to collect a myriad of data, from temperature and humidity to occupancy. Instead of relying on a traditional light switch, a PoE-powered luminary could automatically turn on when an individual enters the room, and turn off when the person leaves. Because the lighting system is connected to the network, individuals connected to the network could control the lights using a controller or mobile/computer application. They don’t even have to be near the smart fixture – as long as they have access to the network, they could, technically, control the features of the luminary.
According to analysis by director of business management and electrical engineer Alec Makdessian and Thong Hunyh, the power efficiency of PoE-capable lights is considered to be better than an AC-powered system, but only when the output power is low and the length of the CAT5 or CAT6 cable is short. Additionally, the amount of power during transmission is not strong enough to power large lighting systems, even at the limits of PoE technology.
During installations, it is also recommended to take the possibility of electrical noise or interference into consideration, to prevent sensitive electronics from malfunctioning when operating nearby PoE-powered LED fixtures.
A major risk in using network-powered lights is the possibility of power outages stemming from the network. In an earlier example provided, a lighting system that was connected to the Wi-Fi network of the stadium hosting Super Bowl XLVII was able to stay operational because it was connected to emergency backup power. The opposite could also happen, with the Wi-Fi network losing connection to power, resulting in loss of lighting.
Lastly, IoT systems, unfortunately, are plagued with serious security issues. Without a secure network, hackers could easily compromise the network and take control of the lights. For businesses, this is a major barrier for adoption. Flickering the lights or shutting them down could greatly affect operations. For example, if PoE lighting systems installed in conference rooms were compromised by a hacker, a business would need to move meetings to a different part of the building, until operators are able to regain control of the network.