Cable Temperature Rise Caused by PoE
We need to know the expected temperature rise caused by PoE self-heating so we can estimate more accurately the maximum temperature of the cable, and thus prevent deterioration in signal-transmission capabilities (increase in Insertion Loss).
We will keep this simple. Temperature rise and the maximum allowable PoE current was the subject of several committees, reports, and intense discussions, especially during the creation of the IEEE 802.3at standard. But the dust has settled, so it is enough to just quote the results that matter to us going forward.
Initially, during the creation of the older (IEEE 802.3af) standard, the logic was very simple. The TIA liaison reported that existing infrastructure was ...