Poe Overview - NETGEAR GS728TXPv3 Hardware Installation Manual

24-Port and 48-Port Gigabit Ethernet PoE+ Smart Switches with 4 SFP Ports or 4 10G SFP+ Ports

PoE overview

The switch can supply up to 30W Power over Ethernet Plus (PoE+, IEEE 802.3at) to each
copper port, up to the maximum power PoE budget for all active PoE+ ports. The switch
is backward compatible with PoE (IEEE 802.3af).
The number of PoE+ ports and the maximum PoE power budget across all active PoE+
ports depends on the switch model:
• GS728TPv3: 24 PoE+ ports with a maximum PoE power budget of 190W
• GS728TPPv3: 24 PoE+ ports with a maximum PoE power budget of 380W
• GS728TXPv3: 24 PoE+ ports with a maximum PoE power budget of 190W
• GS752TPv3: 48 PoE+ ports with a maximum PoE power budget of 380W
• GS752TPPv3: 48 PoE+ ports with a maximum PoE power budget of 760W
• GS752TXPv3: 48 PoE+ ports with a maximum PoE power budget of 380W
Supplied power is prioritized according to the port order, up to the total power budget
of the device. For example, for model GS728TPv3, port 1 receives the highest PoE
priority, while port 24 is relegated to the lowest PoE priority.
If the power requirements for attached devices exceed the total power budget of the
switch, the PoE power to the device on the highest-numbered active PoE+ port is
disabled to make sure that the devices connected to the higher-priority, lower-numbered
PoE+ ports are supported first.
Although a device is listed as an 802.3at PoE+–powered or 802.3af PoE–powered device,
it might not require the maximum power limit that is specified by its IEEE standard. Many
devices require less power, allowing all PoE+ ports to be active simultaneously when
the devices correctly report their PoE class to the switch.
Table 4. PoE classes and PoE power allocations
Device Compatible PoE
Class Standard
0 PoE and PoE+
1 PoE and PoE+
2 PoE and PoE+
3 PoE and PoE+
4 PoE+ only
The previous table shows the standard power ranges, calculated with the maximum
cable length of 328 feet (100 meters). If a device receives insufficient PoE power from
the switch, consider using a shorter cable.
Applications
Class Description Maximum Power
Reserved for the Device
Default power (full) 15.4W
Very low power 4.0W
Low power 7.0W
Mid power 15.4W
High power 30.0W
23
Power Delivered to the
Device
0.44W–12.95W
0.44W–3.84W
3.84W–6.49W
6.49W–12.95W
12.95W–25.5W
Hardware Installation Guide