Table 4. PoE port capacities and budgets
Switch PoE BudgetPort CapacityPoE portsModel
125W30W8 PoE+ (802.3at)M4250-10G2F-PoE+
240W30W8 PoE+ (802.3at)M4250-10G2XF-PoE+
720W90W8 PoE++ (802.3bt)M4250-10G2XF-PoE++
Supplied power is prioritized according to the port order, up to the total power budget
of the device. Port 1 receives the highest PoE priority, while port 8 is relegated to the
lowest PoE priority.
If the power requirements for attached powered devices (PDs) 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 might be listed as an 802.3bt PoE++-powered or 802.3at
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 8 PoE ports to be
active simultaneously when the devices correctly report their PoE class to the switch.
Table 5. PoE classes and PoE power allocations
Power Delivered to
the PD
Maximum Power
Reserved for the PD
Class DescriptionCompatible PoE
Standard
Device
Class
0.44W–15.8W15.4WDefault power (full)PoE, PoE+, and PoE++0
0.44W–3.84W4.0WVery low powerPoE, PoE+, and PoE++1
3.84W–7.2W7.0WLow powerPoE, PoE+, and PoE++2
6.49W–15.9W15.4WMid powerPoE, PoE+, and PoE++3
12.95W–30.8W30.0WHigh powerPoE+ and PoE++4
25.5W–47.0W45.0WUltra high powerPoE++5
51.0W–64.4W60.0WUltra high powerPoE++6
62.0W–81.1W75.0WUltra high powerPoE++7
71.0W–96.5W90.0WUltra high powerPoE++8
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.
Hardware Installation Guide24Hardware Overview
AV Line of Fully Managed Switches M4250 Series
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