Poe and LED LIGHTING
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THE BEGINNERS GUIDE TO PoE AND LED LIGHTING Hubbell Premise Wiring A VERY BRIEF HISTORY OF LIGHTING TECHNOLOGY Power over Ethernet (PoE) lighting has been a buzz worthy topic in both the lighting and network cabling worlds for several years, yet much of the information that surrounds it is unclear or often misunderstood. This whitepaper focuses on the practical applications of PoE, as well as creating an understanding of how we have reached this point in the advancement of lighting technology. 18TH CENTURY 20TH CENTURY THE NEXT GENERATION Gas lighting Neon lighting, fluorescent lamps, LED Power over Ethernet (PoE) and compact fluorescent light bulbs technology for LED PRE-HISTORY 19TH CENTURY 21ST CENTURY Torches, Oil Lamps, Candles Kerosene lamps, LED filament light bulbs, incandescent light bulbs LED screw-in light bulbs To understand the convergence of light-emitting diodes lasted longer than incandescent bulbs and consumed (LEDs) and PoE, it’s helpful to first understand the main approximately one-third of the energy. This finding driver in technological change and advancement within allowed fluorescent to prevail as the lighting of choice the lighting industry. Economists and social scientists for the next several decades until the next driver of theorize that technological innovation is a result of one lighting advancement surfaced. of two opposing models: The “push” model, meaning Following the 1973 oil crises and subsequent broader that advancement – often in the form of a product – energy crises, the need to save energy again created is pushed out to the marketplace fulfilling an unknown a demand. This time, industry research resulted in the need, or the “demand-pull” model which begins with a development of the Compact Fluorescent Light (CFL). market need followed by research, development and Arriving on the market in the mid-1980’s, CFL attained ultimately the launch of a new product. Essentially and eventually surpassed cost parity with fluorescent economic conditions, demographics and our social within the first few years of the 21st century. environment drive the acceptance or denial of technological innovation and progress. Throughout In the United States, lighting accounts for approximately the 20th century, advancements in lighting technology 9.5 percent of the average total electricity consumed by were a result of both models. the residential sector, increasing to 11 percent in the commercial sector. However, improving efficiency in The initial push of fluorescent lighting research from lighting technology has led to decreased consumption in the late 1920’s and early 1930’s transitioned to a recent years. A snapshot from an average office building demand-pull model during World War II as U.S. factories fifteen years ago would place that figure closer to 20 which were working overtime sought out more efficient percent, or even higher depending on the climate zone. lighting. Research determined that fluorescent lights How does this information relate to technology in 2017? The Beginners Guide to PoE & LED Lighting | 2 MAKING THE CASE FOR LED Today’s LED bulbs are also six to seven times more energy efficient than “conventional incandescent lights, cut energy by more than 80 percent, and can last more than 25 times longer. Taken together, these advancements have led to rapid deployment in the past few years in both commercial and residential applications. In 2012 alone, more than 49 million LEDs were installed in the U.S. – saving about $675 million in annual energy costs – and as prices continue to drop, LEDs are expected to become a common feature in homes across the country. ” — U.S. Energy Department’s website To further substantiate this data a USA Today article by Kellie Ell from June, 2017 states that in recent years the price of an LED light bulb has dropped by 85 percent and that since 2009. In addition, the number of LED bulbs installed in U.S. households has jumped from less than 400,000 in 2009 to 78 million in 2014. The article goes on to compare the ten year costs of an incandescent, halogen and LED light bulb (60 watt GE LED bulb with an average kilowatt/hour cost, purchased from a national retailer). The costs for each bulb were: INCANDESCENT HALOGEN LED $78.80 $76.80 $17.25 The evidence overwhelmingly suggests that higher front end costs of an LED bulb are quickly offset by low operational, maintenance and replacement costs, providing an ROI that’s easy to quantify. The Beginners Guide to PoE & LED Lighting | 3 OPPORTUNITIES AND LIMITATIONS: PRESENT DAY PoE Compared to traditional incandescent or CFL bulbs, LED continuously escalating. Although most PoE systems do bulbs have a significantly lower wattage requirement, not utilize the maximum allowable current on all four which has acted as a catalyst for the development of pairs, the proposed application standard (IEEE 802.3bt) PoE lighting technology. specifies that up to 1A per pair can be supplied to the device over the structured wiring system. PoE is a method of transferring low voltage power and data over the same category cable. It is not a new Concurrently, the TIA is developing TSB-184-A which innovation, but has a history dating back to 2000 when describes the steps recommended to support these Cisco first applied the technology to power Voice over increasing power requirements. Maximum current Internet Protocol (VoIP) phones, causing its popularity levels for a structured cabling system are set and based to grow exponentially. IEEE first set standards for PoE on; copper cross sectional area, de-rating necessary in 2003 with the ratification of 802.af, which allowed for for bundling, maximum cable capacity, maximum 15.4 watts of power injected (13.5 watts delivered) on environmental temperature, and the maximum each port, utilizing a power source and a power device. allowable temperature rise in the cable. It has been assumed that connectors do not represent the limiting Initially the most common devices were VoIP phones, IP factor in the system. This assumption is generally cameras, wireless access points, intercom, Network Time correct, however improperly designed connectivity Protocol wall clocks, sensors and access controls. This may not support the required current without standard was limited to power over two cable pairs. detrimental effects. IEEE 802.3at, also limited to two cable pairs, was passed in 2009, however with an increase to 30 watts injected In addition to normal UL and NEC safety standards, (25.5 watts delivered). the next level of verification assures that the connectors can continuously conduct required current levels without Nate Herring, Senior Product Manager for Hubbell overheating. Excessive heating can reduce electrical Premise Wiring provided this insight into the performance characteristics of connectors. Plus, heat development and advancement of PoE, noting its can increase the likelihood of failure in the form of trace potential as well as limitations: severing or de-lamination of the printed circuit board “Proliferation of PoE enabled devices and systems FR4 substrate. New standards allow for power insertion continues to drive the need for higher levels of DC on all four pair combinations. As a result, the maximum power over structured cabling systems. This is being expected current through a connector is 1A on each of driven by a rapid increase in the total number of PoE the four pairs. devices deployed with each device requiring more The current carrying capacity of connecting hardware power. Through the iterations of IEEE 802.3af, IEEE is determined by the thickness and width of the current 802.3at, and now IEEE 802.3bt, the maximum current carrying printed circuit board (PCB) traces (a trace is the drawn across the cabling infrastructure has been The Beginners Guide to PoE & LED Lighting | 4 continuous path of copper lines on a PCB). Industry designed to exceed this minimum industry requirement design rules suggest that a 0.0015” thick (1 oz.) trace on all current carrying paths. Hubbell conducts power that is 0.015” wide is capable of handling 0.55A of testing to ensure that connectivity exceeds minimum current with less than 10 degrees Celsius of temperature requirements and provides at least a 50% current rise (50 degrees Fahrenheit). Hubbell Premise Wiring carrying capacity margin over existing and proposed connecting hardware products have always been applications.” OPTIMIZING LED WITH POE The advantages of LED lighting for new construction Recently, PoE lighting has also been explored as a or as a retrofit are evident, but what are the additional method to improve security, particularly in high- real life benefits of powering LED lighting via PoE? occupancy buildings such as schools and hospitals. As with traditional LED lighting, cost savings is a The technology can be setup to change color during major factor. Some estimates provide a minimum security threats, helping to identify a clear path of 15 percent savings in total cost of ownership over towards emergency exits. In addition, it can even be a ten year period when LED lighting and controls used to inform security personal of the location of the are combined with PoE. In commercial buildings, threat or hazard. lighting systems have historically been powered by a dedicated 227V AC infrastructure, requiring the Spanning beyond security and safety, PoE capabilities installation of additional control sensors in some have also been applied to support health and instances as a secondary network. This ultimately wellness. For example, light levels and temperature adds to the building’s capex and opex through can be adjusted to more effectively simulate a natural increased maintenance costs. range of light in windowless habitable spaces. This “healthier” lighting can help minimize the adverse Adding to smart building capability, PoE can be effects on circadian rhythms (your 24 hour internal used to deliver critical building data captured clock or sleep/wake cycle) typically experienced with through the lighting system – such as movement traditional artificial light.