Influence of Heat on Link Lengths

When the cable heats up due to the effect of the current, its attenuation increases, reducing the possible transmission range. This applies in particular to the new 4PPoE (4-Pair Power over Ethernet) with a 55 or 100 watt output, where up to one amp can flow through each wire pair.

However, the actual temperature increase does not just depend on the cable and the PoE application, but also on the way the cables are laid (bundle size) and the ambient conditions (e.g. heat build-up through an insulated wall duct system). For PoE-capable cabling to fulfill its function properly, it is therefore not just a matter of selecting the right material, but also of correct planning and installation.

A crucial factor for every project is which applications the cabling needs to be configured for. In the long run, is 1 Gigabit Ethernet with class D or E cabling sufficient? Or will 10 Gigabit Ethernet and class EA cabling or higher be required? This process means planners will also have to investigate the parameters for PoE in greater detail in future.

For this purpose, R&M developed a PoE Calculator on the basis of an Excel file with which the possible link lengths can be determined. It can be downloaded from the company’s website.

Video “R&M explains Power over Ethernet Cabling:

The PoE Calculator can be downloaded as an Excel file.



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Matthias Gerber

By Matthias Gerber

Market Manager LAN