Power over Ethernet PoE Surge Protector

Power over Ethernet PoE Surge Protector

Created by: Glen Zhu | Updated Date: December 15th, 2023

Power over Ethernet PoE SPD

Now ethernet has emerged as the dominant standard for wired networking, providing high-speed data transmission and reliable connectivity. Its widespread adoption has revolutionized the way people communicate and share information.

How do surges threaten networks?

Ground potential surge due to a nearby lightning strike to the ground:

A lightning strike to the ground is comprised of multiple strokes, each varying in intensity, leading to currents in the tens of kiloamps. The currents flow through surface layers like soil and rock, resulting in substantial voltages due to the ground’s imperfect conductivity. In extreme cases, direct strikes can reach 100kA to 200kA.

Given the ground’s imperfect conductivity, lightning currents create significant potential differences across the Earth’s surface. For instance, with 100kA flowing through a relatively modest ground resistance of 10 ohms, a ground potential surge of 1 million volts can develop over several meters of ground.

In the proximity of a ground strike, two buildings separated by some distance will undergo varying potential shifts. The electrical earths of these buildings, interconnected through systems like rods and mats, may momentarily display significant potential differences. If a cable, like a LAN cable, links the buildings, equipment in one may be exposed to the relative ground potential of the other, potentially causing damage when current flows due to destructive breakdown within the LAN equipment. The surge voltage is contingent on factors such as the location of the lightning strike, its current, ground resistivity, and the distance between the buildings, as illustrated in Figure 1.

Figure 1 – Ground potential surges caused by a cloud-to-ground strike

Side flash:

Figure 2 depicts the occurrence of side-flash. In this scenario, lightning strikes an air termination and descends down a surface conductor of the building. The voltage along a cable, influenced by rapidly changing current and the cable’s self-inductance, plays a crucial role.

Side-flash becomes a concern when cables, sharing the potential of the surrounding earth, run close to non-metal-clad walls. The scenario is rather extreme, and the resulting current can lead to substantial damage. However, with modern construction techniques incorporating bonded and earthed structural metalwork, such occurrences should be relatively infrequent.

Figure 2 – How side flash occurs

Surges induced by capacitive or inductive coupling:

Voltages induced by capacitive or inductive coupling pose a threat to LAN and Ethernet systems. These induced voltages can result from the close proximity of electrical circuits or devices carrying alternating currents. Capacitive coupling occurs when an electric field causes voltage differences between nearby conductors, while inductive coupling involves the mutual induction of voltages in nearby conductors due to changing magnetic fields.

The induced voltages can lead to interference and disruptions in LAN and Ethernet communications. The coupling effect may introduce unwanted signals, noise, or distortion into the network, affecting the integrity and reliability of data transmission.

Figure 3 – Surges induced by capacitive or inductive coupling

Ethernet cables

Ethernet cables, often referred to as network cables, serve a fundamental role in networking by connecting various devices such as routers, modems, switches, and computers. Acting as the conduits for data traffic, these cables enable access to local area networks (LANs) and the internet. Despite the prevalence of Wi-Fi technology, ethernet cables remain crucial, especially in business environments where a hardwired network ensures consistent, high-speed connectivity. Unlike Wi-Fi, ethernet-connected devices are immune to sudden drops in performance caused by obstructions or interference.

Structured cabling serves as a versatile and consistent connection infrastructure accommodating diverse services such as analog telephones, ISDN, and various network technologies. Structured ethernet cables help protect ethernet from lightning and surge effects.

Its primary advantage lies in its adaptability, allowing seamless integration of new tasks without the need to replace cables or connection components. This system offers application-independent and universal cables that are not tied to specific network topologies, manufacturers, or products, ensuring compatibility with both current and future protocols.

Comprising three hierarchical levels, a universal cabling system starts with campus backbone cabling, connecting the campus distributor to building distributors using optical fiber cables for data networks. Building backbone cabling follows, linking building distributors to floor distributors through optical fiber cables and balanced 100-ohm cables. The third level, horizontal cabling (floor distributor), encompasses cables for workstations on a floor, typically utilizing copper cables or 62.5 µm optical fiber cables to connect to telecommunication outlets.

Ethernet cables, which serve as the backbone of networking, are categorized based on bandwidth, data rate, and shielding. Shielding is a crucial factor in protecting cables from electromagnetic interference (EMI) and radiofrequency interference (RFI), which can affect signal integrity. Shielded Twisted Pair (STP) cables, for instance, feature additional shielding to minimize external interference. The shielding becomes especially important in environments with high EMI or RFI, such as industrial settings.

The choice between shielded and unshielded cables can significantly impact surge protection within the network. By shielding against electrical interference, cables help minimize the risk of surges affecting data transmission.

In the context of structured cabling, the shielding of ethernet cables can be particularly relevant in scenarios where reliable and uninterrupted connectivity is critical. For instance, in environments with heavy machinery or other sources of electromagnetic interference, opting for shielded cables at both the horizontal cabling (floor distributor) and backbone levels can enhance the overall robustness of the network and contribute to ethernet cable lighting protection.

Ethernet cables are commonly terminated using RJ45 connectors, with options like molded connectors and snagless connectors providing durability and protection. Patch cables, featuring connectors at both ends, are shorter and ideal for connecting devices within proximity.

Beyond the traditional types, innovative ethernet cables, such as slim cables with reduced diameter, flat cables suitable for specific use cases, and armored cables designed for outdoor applications, offer flexibility and adaptability in various scenarios.

In special conditions, considerations like fire safety may necessitate cables with higher resistance and lower toxicity, while antibacterial cables find applications in environments where preventing bacterial infections is crucial. Power over Ethernet (PoE) technology enables the simultaneous transmission of power and data over a single cable, a valuable feature for devices like IP cameras and wireless access points.

Electromagnetic compatibility concept (EMC)

In the rapidly evolving landscape of technology, where information seamlessly courses through the intricate veins of our digital infrastructure, the significance of dependable and interference-free communication cannot be overstated. Within Ethernet networking, Electromagnetic Compatibility (EMC) operates discreetly yet significantly, contributing to the reliability of data transmission.

Ethernet cables, often overlooked components of connectivity, harbor an essential feature: shielding. Shielded Twisted Pair (STP) cables incorporate an added protective measure to specifically repel unwanted electromagnetic interference. The shielding serves as impervious armor, deflecting electrical noise away from the vital conductors and safeguarding the integrity of the transmitted signal. It represents the primary defense against imperceptible forces that could otherwise disrupt digital communications.

In the realm of Electromagnetic Compatibility (EMC), grounding acts as a stabilizing force, steadfastly maintaining the equilibrium of the system. Adhering to proper grounding practices for networking equipment – encompassing routers, switches, and servers – establishes a stable reference point for electrical currents. It not only prevents equipment from becoming a source of interference but also ensures the entire network operates within a harmonious electrical environment.

The intertwining of twisted pairs within Ethernet cables isn’t just for show; it’s a purposeful design to minimize interference and ensure smooth data transmission. This design is like a well-rehearsed routine, where each element is carefully calculated to sustain communication amidst the complexity of electromagnetic signals.

In the world of networking, standards are crucial. Organizations like the International Electrotechnical Commission (IEC) and the Institute of Electrical and Electronics Engineers (IEEE) set benchmarks for Electromagnetic Compatibility (EMC). Following these standards ensures that networking devices can coexist harmoniously, sharing the electromagnetic spectrum without causing disruptions. The adherence aligns with regulatory principles on the data highway, preventing collisions and ensuring a smooth flow of information.

EMC design

To sustain the effective performance of data networks in the context of evolving requirements, careful consideration of electromagnetic compatibility (EMC) is paramount. Assessing the electromagnetic environmental conditions involves evaluating potential sources of interference, the quality of electrical energy, lightning strike risks, and possible emissions.

To safeguard data transmission against interference, a comprehensive EMC strategy should be integrated into the network design, which includes a detailed earthing and equipotential bonding concept covering cable routing, structure, active components, lightning protection, signal line shielding, and surge protection.

Key Measures for EMC and Uninterrupted Data Transmission:

Spatial Separation: Detect and isolate potential sources of electromagnetic interference, such as transformer stations or elevator drives, from components within the information technology realm.

Cabling Infrastructure: In regions affected by potent radio transmitters, utilize enclosed, grounded metal conduits. Contemplate the utilization of optical fiber cables to establish connections for end devices, thereby fortifying isolation.

Circuit Isolation: Enforce the creation of distinct circuits for end devices, integrating noise filters and uninterrupted power supply systems as warranted.

Avoiding Parallel Installation: Abstain from the concurrent installation of power and data lines for end devices grappling with substantial loads or acknowledged interference origins.

Shielded Data Cables: Deploy shielded data cables, grounded at both terminations, and seamlessly integrate patch and connecting cables into the overarching shielding framework.

Equipotential Bonding: Infuse reinforcement, such as intermeshing, into the potential equalization structure designed for metal enclosures and shields.

Riser Duct Arrangement: Assure the shared usage of riser ducts by shielded data cables and power lines in the building backbone region, averting the adoption of separate ducts and sustaining a 20 cm gap between diverse cable types.

Horizontal Cable Routing: Route power lines for devices and pertinent data lines along the same cable path, maintaining separation with designated webs. In horizontal expanses, uphold a maximum 10 cm distance between power and data lines.

Lightning Protection Integration: In scenarios where a lightning protection system is in place, uphold prescribed safety distances between power/data lines and external elements of the lightning protection infrastructure.

Optical Fiber Usage: Choose optical fiber cables for the interlinking of information technology cables across different edifices, particularly in the context of campus backbone cabling.

Surge Protection: Deploy surge protective mechanisms within power circuits and horizontal cabling frameworks to shield against transient occurrences arising from both switching activities and lightning discharges.

Power Installation Strategy: Execute a TN-S system for the power infrastructure to preclude interference currents impacting data line shields.

Equipotential Bonding Hub: Instate a centralized hub for potential equalization, aligning with the power installation (PEN) at a specified locale within the structure, such as the service entrance room.

By adhering to these measures, the network can effectively mitigate electromagnetic interference, guaranteeing reliable data transmission even in the face of increasing demands.

Figure 4 – Shielded connection on both ends to prevent equalizing currents

Figure 5 – Equipotential bonding of a shielded cable system

Protective effect

Ethernet networks exhibit a strong protective capability, safeguarding the secure and efficient transmission of data. Key to this safeguarding is the assurance of data integrity facilitated by inherent features and protocols like TCP/IP, integrating error detection and correction mechanisms. Expanding further, the network’s defensive arsenal incorporates stringent security measures against unauthorized access and potential threats, utilizing encryption protocols and firewalls. These collective measures bolster the overall protective effect, reinforcing the security posture of Ethernet networks.

Addressing the critical concern of network reliability involves the integration of redundancy and fault-tolerant features. Redundant paths within the infrastructure enable uninterrupted data transmission, even in the event of component failures. The fault tolerance ensures the seamless operation of critical systems, alleviating the impact of disruptions and contributing to the inherent protective nature of the network.

Crucial to enhancing performance and resilience are Quality of Service (QoS) mechanisms and physical layer protection. QoS prioritizes various traffic types, affirming efficient network operations, particularly for time-sensitive data like voice or video. The protective measures extend to the physical layer, involving shielded Ethernet cables and surge protection devices that guard against electromagnetic interference and voltage spikes. These measures play a significant role in upholding signal integrity and preventing damage to connected equipment, reinforcing the network’s resilience.

Ethernet networks integrate sophisticated monitoring tools, including Intrusion Detection Systems (IDS), to elevate their protective capabilities. Continuous performance monitoring enables real-time issue identification, empowering proactive troubleshooting and maintenance. The proactive approach strengthens the network’s protective measures by addressing potential problems before they escalate.

Scalability emerges as a key attribute, allowing seamless expansion without compromising performance. The scalability contributes to the network’s enduring protective effect, accommodating growth and evolving operational requirements. Additionally, Ethernet networks play a pivotal role in disaster recovery plans, implementing backup and recovery strategies, redundant systems, and offsite data storage for enhanced protective capabilities.

In the realm of electromagnetic compatibility (EMC) testing, Ethernet networks must demonstrate defined immunity to conducted interference. Immunity levels, ranging from 1 to 4, are contingent on test levels, underscoring the necessity for diverse immunity levels tailored to environmental conditions. Surge arresters assume a crucial role in constraining conducted interference to acceptable levels, preserving that the immunity of terminal devices is not breached. The product family introduces an SPD class sign, simplifying the selection of surge arresters aligned with the specific requirements of terminal devices.

Well-sized surge arresters are crucial for shielding terminal devices from voltage and energy peaks, ultimately improving the overall availability of installations. As communication networks evolve into high-frequency realms, a comprehensive EMC concept becomes imperative, encompassing lightning and surge protection for both buildings and systems. The comprehensive strategy supports the seamless operation of networks and underscores the protective capabilities of Ethernet networks amid ever-evolving technological landscapes.

Surge Protective Devices

For optimal surge protection, collaboration between electricians, IT experts, and the device manufacturer is essential. Coordination of measures for various systems should be undertaken, necessitating the involvement of specialists such as engineering consultants, especially for large-scale projects.

Figure 6 – Diagram illustrating the application of surge protection devices in buildings.

To provide thorough protection against overvoltage surges in the networking system, it is essential to install a systematic array of network surge protectors at critical locations within the building or compound where the networking infrastructure is deployed.

At the core of the electrical system, the main distribution board is equipped with a strong defender against high-energy surges – the type 1 surge protective device FLP25-275/3S. The smart placement helps the system’s durability by effectively handling and diverting potentially damaging voltage spikes. In localized circuit distribution, sub-distribution boards employ reliable type 2 surge arresters SLP40-275/4S, chosen for their ability to manage and suppress moderate surges.

As the network extends to the server, intricately connected to the Ethernet infrastructure, a crucial line of defense is established at the entrance point.

Here, type 3 surge protectors, exemplified by the TLP-255/2S, come into play.

Designed to provide targeted protection against low-energy transient voltage events, TLP-255/2S fortifies the integrity of the networking components.

Deploying these surge protectors safeguards the server, a vital data exchange hub, from disruptions caused by minor voltage fluctuations.

Deploying these surge protectors safeguards the server, a vital data exchange hub, from disruptions caused by minor voltage fluctuations.

Power over Ethernet (PoE) and surge protection

Power over Ethernet, or PoE, describes any of several standards or ad hoc systems that pass electric power along with data on twisted-pair Ethernet cabling. This allows a single cable to provide both a data connection and enough electricity to power networked devices such as wireless access points (WAPs), IP cameras and VoIP phones.

Power over Ethernet (PoE) has become a fundamental technology in modern network deployments, offering the simultaneous transmission of data and electrical power over a single Ethernet cable. As organizations increasingly rely on PoE to power various devices such as IP cameras, access points, and sensors, securing a resilient surge protection system is essential for preserving network integrity and protecting connected equipment.

PoE systems are susceptible to electrical surges that can originate from various sources, including lightning strikes, power grid fluctuations, and industrial equipment operations. The DT-CAT 6A/EA ethernet surge protector is specifically designed for equipment connected to Power over Ethernet networks and is perceived as one of the best ethernet surge protectors. The device protects networking from being damaged from transient overvoltage surges and can be applied to network transmission speed up to 10 Gigabit and category 6A. And of course, it is applicable for ethernet networks with lower categories.

The transient protection circuit employs high-energy gas discharge tubes (GDT) and a network of fast-response silicon avalanche diodes (SAD) to ensure precise clamping of exceptionally large surge events.

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