A safe PoE operation is an outcome of different combining factors. Of these, the five important ones are - temperature ratings, conductors, cable material, cable design, and installation mechanism. A slight deflection in any of these fundamental factors can lead to an efficiency drop in the PoE transmission network. In extreme cases, it is possible to result in abrupt damage to the PoE transmission network. Therefore, consideration of the following five factors is essential while selecting cables for Power over Ethernet (PoE).

Temperature Rating: The temperature rating means the highest amount of temperature that can be sustained by the cable’s jacket or shielding. The cables for PoE transmission should have more than 60˚C of temperature rating. A higher temperature rating is essential as the higher the temperature rating, the higher is the power dissipation via the copper cable. Therefore, while selecting cables for Power over Ethernet (PoE), the temperature rating of the cable must be checked. Commonly PoE cables with 60˚C, 75˚C, and 90˚C are the temperature ratings available in the market. However, temperatures over 200˚C of temperature rating can be achieved in PoE cables.Keeping the temperature range of the cable between 50 and 90 degrees Celsius is good for the network performance and long operation life of cables. If the temperature gradient of the cables is crossed, that means if the generated temperature in the cable exceeds the temperature gradient, then the electrical signal transmission degrades. Also, if the operating or environmental temperature exceeds the allowed temperature rating, it can affect the longevity and performance of the cable. If your application demands more energy, high gauge cables such as Cat 6e are useful in reducing energy wastage and resistance. This is especially useful in applications involving high working temperatures and closed environments.

Size of a Conductor Gauge: The conductor resistance is one of the factors responsible for heat generation in PoE cables. The conductor resistance is higher in small gauge diameter cables, which generate a high amount of heat. Thus, the purpose behind checking for a conductor gauge size is to reduce heat generation or increase heat dissipation through the cable body. To achieve this, a larger connector gauge diameter must be selected. A connector with a larger diameter increases the heat dissipation across the length of the PoE cable. The heat is generated due to connector resistance or insertion losses, and the generated heat is dissipated throughout the cable.It is always ideal to choose Cat6 or Cat7 PoE cables instead of Cat5e cables. Cat6 cables are known to have about 80% lesser connector resistance (DCR) as compared to the Cat5e cables. Therefore, cables with a larger diameter, lesser conductor resistance, lesser heat generation, and higher heat dissipation must be considered for PoE applications.

Cable Construction: The construction of copper cables contributes to heat generation and dissipation.There are two common types of copper cable construction, namely, unshielded twisted pair cable (UTP) and shielded twisted pair cable (STP). Generally, STP cables with foil or metallic shields are known to offer higher heat dissipation than UTP cables. The higher the heat dissipation, the cooler is the cable. Therefore, selecting a category 6 or category 7 STP cable with foil or metallic shields are advised.Network cables such as Cat 5e and Cat 6 are commonly used. These cables comprise eight wires which are four twisted pairs. Two of these are called data pairs as they are used for data transfer. The other two twisted pair cables transfer electrical signals through them. Out of the four twisted pairs, POE can use the data pairs for either of these two functions.

Installation Mechanism: The type of installation or connectivity mechanism of the copper cable determines thermal resistance and insertion losses. The installation configuration is expected to have low insertion loss, easy connectivity, and a good heat dissipation factor. Inappropriate use of installation mechanisms can result in conduit effect, and trapped heat which can further damage the physical and operational performance of the cable.For instance, cables connected to POE switches in the middle of a bundle produce more heat than those on the outer sides of the bundle. This happened more in closed environments as heat radiation reduces. So, two aspects are important in this case- a proper ventilation system in the environment and loosening and segregating large cable bundles.

Cable Material: When it comes to selecting a PoE cable, one can get two common choices, namely, copper clad aluminum (CCA) and pure copper cable. The pure copper cable has been traditionally used in PoE applications and is expensive. The copper-clad aluminum cables are economic, however, these cables may lead to interruptions during PoE transmission due to inferior materials used. The copper-clad aluminum cables generate high resistance, which leads to radiant heat generation in the long run. On the other hand, pure copper cables offer less resistance and less heat generation, therefore, it can be used for a longer run without any impact on data transmission speed. Selecting the correct cable material for the PoE applications can help in enhancing PoE transmission efficiency.Ethernet cables such as SPF Cat 6 and PoE switches are crucial to build this network. Appropriate type of cable, their structure, and installation directly affect the quality, performance, and speed of the network.