3. February 2022

5 Min read

    Contents

      Written by Matthias Gerber

      Market Manager Local Area Networks

      PoE useful for smart buildings

      Power over Ethernet – supplying power using data cables – is an ideal way to supply power to building automation devices around the clock. The latest PoE generation even delivers current via all four twisted pairs of the data cable. That’s why it’s called 4PPoE.

      With 4PPoE, up to 90 watts of electrical power are feasible. This is more than three times as much as the previous standard – and more than six times as much as the original PoE standard. Ninety watts of power can be used to control, move, regulate or switch many Internet-enabled things in smart buildings. This is why many people also refer to it as high-power PoE. We even see 4PPoE as a door opener for ALL-IP smart buildings.

      Planning PoE precisely at all times

      As always with «hot» new technologies, there are a few critical aspects with high-power PoE that demand our attention. Users should try to keep a cool head and only venture into PoE installations and PoE applications with careful planning.

      Three «hot» factors influence the cabling with 4PPoE and thus also the quality of signal and data transmission in the LAN:

      • Cables and cable bundles heat up as a result of the current supply. The material suffers. Higher attenuation losses can affect data transmission in the LAN.
      • Disconnecting a plug connection under load causes sparks. Spark erosion can damage the spring contacts in the RJ45 adapters. Poor contacts = poor signal transmission.
      • Contact resistances on the wire contacts may increase if the contacting surfaces become loose, age, or corrode. This, too, has an adverse effect on data transmission.

      Here are three answers from R&M: Plan/specify correctly and implement accordingly. Select suitable products. Use the optimum connection technology.

      • With a PoE-compliant design, the cabling system can withstand higher temperatures. One of the most important preventive measures is to plan shorter links if required that take into account the underlying conditions of the installation. The shorter the cable run, the smaller the attenuation losses during data transmission and the greater the reserves for heating effects. The free PoE calculator from R&M helps you to compare cable types, diameters, bundle size, channel properties, and lengths. The PoE calculator is a practical Excel spreadsheet.
      • Whether an RJ45 socket will suffer from spark erosion depends on its mechanical construction and the contact design. These characteristics should be taken into account when selecting a product and specified accordingly. The IEC 60512-99-1/2 standards are available for this purpose.

      The connection technique of the signal conductor can also have a major influence. Therefore, the advantages and disadvantages of the prevailing wiring technologies should be taken into account when selecting a product: Insulation Piercing Contact (IPC) and Insulation Displacement Contact (IDC). Only IDC products should be selected for systems with continuously high PoE performance and when using 4PPoE. To make planning, product selection, and purchasing easier, R&M has introduced the PowerSafe quality seal for products with IDC connections.

       

       

      R&M is a leader in PoE

      Power over Ethernet is rightly generating high expectations. R&M is dedicated to PoE development and PoE cabling and, as a pioneer of IDC wiring technology, is setting standards here as well.

      Furthermore, R&M is on hand to help planners, system integrators, installers, and operators of cabling systems. In addition to the free PoE calculator, R&M also uses a PoE Demonstrator for training purposes. The tool shows how the attenuation of a transmission link increases as a result of heat generation in cables during PoE use and how the function can be ensured by shortening the length.

      And another practical tool

      R&M has developed a small, practical display device for PoE users, service technicians, and IT technicians: the PoE Indicator.

      If you want to find out at a glance which port offers PoE on multiple outlets, use the PoE Indicator instead of a simple dust cover. It contacts the signal pins and detects whether a PoE-capable network device (PSE) is waiting at the other end. This is indicated by a flashing LED. This saves time searching the network documentation.

      I would like to recommend our PoE video. Accompany installer Bob Smith on the path to the right PoE cabling.

       

      What is the difference between IPC and IDC?

      • The insulation piercing contact, IPC, which is frequently used in patch cords, is unstable over the long term. The connection may loosen as the material ages, but also as a result of cable movements. The contact resistance between the contact plate and stranded wire increases as does the risk of heat development and destruction of the connector.
      • Insulation Displacement Contact (IDC) ensures consistently high contact quality over the entire service life of the product. In IDC, a fork-shaped spring contact clamps the wire. The contacts cut through the insulation and press the stranded wire at the side. This makes the connection permanently resistant to tension and vibration, dust-tight, water- and gas-tight, and corrosion-free.