Inching toward a greener, future-proof cabling infrastructure
This year saw noteworthy milestones in the development of cabling infrastructure standards for smart buildings. In March, the Telecommunications Industry Association (TIA) released the ANSI/TIA-568.5 Single Pair Ethernet (SPE) cabling standard. Four months later, TIA released the ANSI/TIA-862-C Intelligent Building standard with technical updates and topologies that facilitate connecting and powering IoT devices, including the addition of SPE standards (in alignment with 568.5). Recently, the National Fire Protection Association Standards Council voted to issue the 2023 National Electrical Code (NEC) with Class 4 fault-managed power that will expand the use of energy-saving direct current (DC) power over low-voltage cabling, which is incentivized by the U.S. Green Building Council’s LEED version 4 pilot credit Direct Current Power Systems.
These milestones encourage cabling infrastructure design and implementation practices that improve connectivity and sustainability in smart buildings—but the market remains in its infancy. The lack of actual products available on the commercial market complicates new-project design. But technology providers can adopt strategies today to help future-proof infrastructure for tomorrow.
More is not better
Per 862-C, the recommended media for smart buildings is Category 6A (Cat 6A) or higher performing cabling. In fact, one of the significant updates from 862-B, released in 2016, is the removal of Category 6 as a recognized media. Cat 6A is a four-pair copper cable that supports data transmission speeds up to 10 gigabits per second (Gbps) simultaneously with up to 90 watts of Power over Ethernet (PoE) to a distance of 100 meters. That makes it the ideal cable for security devices, digital displays, wireless access points, LED lights, and energy-saving smart shades and windows that require fast transmission speeds and/or high power.
While deploying a Cat 6A cabling infrastructure is the current best practice for the bulk of connected devices, the tide may be changing. “Over the past decade, the industry did an excellent job of coming together around four-pair Cat 6A as a single technology and building on it,” says Ronna Davis, director of market development strategy and technology at CommScope. “But we also know that, globally, we need to reduce copper and embodied carbon in our buildings. The caveat is that we need to do it in a way that does not decrease the utility of smart building networks or the ability to bring more power and bandwidth out to the edge.”
"[G]lobally, we need to reduce copper and embodied carbon in our buildings. The caveat is that we need to do it in a way that does not decrease the utility of smart building networks or the ability to bring more power and bandwidth out to the edge."
Davis’ sentiment is echoed by Henry Franc, technology solutions architect at cabling and connectivity manufacturer Belden and chair of TIA’s TR-42 committee, which is responsible for the development and maintenance of premises cabling standards including 862-C. “For many years, the approach to connecting more devices and providing more bandwidth has been to add more cables, but that’s not sustainable,” he says. “The structures our cabling supports can no longer support our waste, and global challenges are pushing us to evolve sooner rather than later. With the addition of technologies like SPE and hybrid copper-fiber cabling, 862-C is more responsive to the environment it’s intended to serve and more relevant to all stakeholders in the smart building ecosystems: telecommunications, electrical, architectural, and mechanical.”
The promise of Single Pair Ethernet
For low-speed, low-power building automation systems (BAS) devices like controllers, actuators, meters, and sensors, SPE supports data transmission speeds up to 10 megabits per second and delivers up to 7 watts of power over single-twisted-pair cabling to at least 1,000 meters. Importantly, it offers the operational benefits of Ethernet to BAS and reduces embodied carbon with only a single pair of copper conductors. SPE cabling, chipsets, and testers are now available, but the active equipment and end devices needed to deploy functioning systems are still in initial development.
That doesn’t mean smart building technology designers need to wait, according to Bob Voss, chair of the SPE subcommittee of the Ethernet Alliance and distinguished engineer at cabling and connectivity manufacturer Panduit. “Testing has demonstrated that traditional fieldbus cabling doesn’t have the geometry to adequately support Ethernet, but we have found that SPE cabling supports traditional protocols just fine,” he says. “That allows new smart buildings to deploy SPE cable today for migration to Ethernet, while maintaining backwards compatibility with existing systems.” With the benefits of SPE already being realized in industrial automation, he adds, manufacturers that make both industrial and BAS platforms are now accelerating their SPE product development road map for smart commercial buildings.
Though supply chain constraints have slowed progress, BAS devices and controllers able to accommodate SPE ports will start hitting the market next year. “Instead of talking about the promise of SPE in nebulous and conceptual terms, we are now working on real-world applications,” Franc says. “I expect to see a number of new products released in 2023—not just cable and connectors, but switches, sensors, and the like.”
“Instead of talking about the promise of SPE in nebulous and conceptual terms, we are now working on real-world applications.”
In the interim, designers need to tread carefully due to established BAS design conventions and protocols. “We need BAS manufacturers to approve SPE cabling for their warranted systems before we can recommend installing it,” Davis says. “SPE cabling could be implemented on a case-by-case basis, but only after designers have done their due diligence. While BAS manufacturers expect to move to Ethernet for improved security, uniformity, and customer demand, their road maps are complicated due to the sheer number of protocols, services, and devices their platforms support.” She expects that large end users with building and industrial automation and a vested interest in SPE will be instrumental in getting more BAS manufacturers on board.
New ways to power
Debuting in the 2023 NEC as Article 726, Class 4 fault-managed power, or digital power, is another technology that will affect smart building cabling infrastructure. Unlike Class 2 DC power, which cannot exceed 60 volts and is limited to 100 watts (and to 100 meters when delivered as PoE), Class 4 DC voltage can go up to 450 volts. At these higher voltages, Class 4 can deliver more power with less copper over greater distances—and with less embodied and operational carbon. For example, with a single-pair 16 AWG cable, Panduit’s fault-managed power system can deliver more than 200 watts of Class 4 power to 2,000 meters, compared to just 14 watts of Class 2 power. Class 4 also improves safety by intelligently limiting the amount of energy that can go into a fault, mitigating risk of shock or fire.
Class 4 power’s entry into the NEC will drive demand and innovation, leading to the development of devices that can accept DC power. In the meantime, a handful of vendor-specific Class 4 systems, including transmitters, receivers, and UL-certified Class 4 cable, are available now with more expected to hit the market next year.
“While big chillers and other power-hungry mechanical equipment will continue to need higher [alternating current] power voltages, Class 4 fault-managed power is going to rapidly change power architecture in commercial buildings,” Voss says. “And it won’t be PoE or fault-managed power; rather, they will coexist together. To plan for the future, smart building cabling designers can specify a zone-type architecture where fault-managed power is transmitted to receivers that convert it to Class 2 power, like PoE, for powering end devices.”
"To plan for the future, smart building cabling designers can specify a zone-type architecture where fault-managed power is transmitted to receivers that convert it to Class 2 power, like PoE, for powering end devices."
Class 2 or Class 4 power also can be delivered via copper conductors in hybrid copper-fiber cables, which have fiber strands for high-bandwidth, long-distance data transmission. Addressed in 862-C, these cables can eliminate the need to deploy and manage telecom rooms for connecting and powering smart devices in large and remote locations, such as warehouses, parking garages, and outdoor spaces. Hybrid copper-fiber cables also eliminate the need for multiple Cat 6A cables; per cabling standards like 862-C, the latest Wi-Fi 6/6E requires two Cat 6A cables to support the bandwidth requirements, if copper cabling is the medium specified in an installation.
Emerging Wi-Fi 7, which is expected to support up to 30 Gbps for augmented reality, video streaming, and expanded IoT applications, will need even more bandwidth. Deploying more Cat 6A cables to each access point is not sustainable, Davis says: “Future Wi-Fi 7 access points will be connected via hybrid copper-fiber cable to support the sustainability, densification, and faster deployment that our customers are asking for.”
An omnipresent conundrum
While industry standards and codes foster new ways to connect and power smart building devices, they sometimes preempt market availability of equipment and devices. “The frustrating part is that you can see the tantalizing technology and even become an evangelist for what it could be, but it often seems just out of reach,” Franc says. “Right now, the best recommendation we can make is to deploy available standards-based copper and fiber cables based on the technologies being deployed today and the technologies likely to be deployed within a reasonable amount of time. But don’t be afraid of newer innovations that use SPE, hybrid copper-fiber cables, or new Class 4 power.”
Every project and owner has a different risk tolerance. Davis recommends that all parties stay informed of upcoming technologies and project applications. “While standards and codes are addressing SPE and Class 4 power, it’s still early,” she says. “But within the next few years, we will see significant changes in smart building cabling infrastructure as solutions become more readily available. So if it’s not for this project, it very well could be the next.”
