PoE++ 802.3bt output switches

802.3bt

— switches that support three PoE standards at once — the relatively new and advanced 802.3bt, as well as the earlier 802.3af and 802.3at.

The features of the last two formats are described in detail in the corresponding help items. And 802.3bt is the newest and most advanced (as of late 2021) PoE standard. One of its differences is the use of not 2, but 4 power wires, which made it possible to increase the power to 90 W at the output (71 W at the load). Such capabilities are indispensable in the power supply of equipment with increased consumption — for example, external surveillance cameras, supplemented by heating systems. On the other hand, support for the 802.3bt standard significantly affects the cost of the switch, and such a connection puts forward special requirements for the quality of cables. In addition, you need to keep in mind that this standard also includes the UPoE format created by Cisco and used in its equipment; and this standard (it is known as PoE type 3) has a more modest power — up to 60 W at the output (up to 51 W at the consumer's input). Yes, and the general standard 802.3bt includes two power classes — class 8, at which maximum performance is achieved, and class 7, where 75 watts are supplied to the output, and about 62 watts reach the consumer. So if you plan to use 802.3bt equipment, when choosing a switch from this category, you must make sure that the power supply is enough for the normal operation of the connected devices.