Enabling PoE for a PoE interface

The system does not supply power to or reserve power for the PDs connected to a PoE interface unless the PoE interface is enabled with the PoE function.

You can enable PoE for a PoE interface if the PoE interface does not result in PoE power overload. Otherwise, whether you can enable PoE for the PoE interface depends on whether the PoE interface is enabled with the PoE power management function. For more information about PoE interface power management, see "Configuring PoE interface power management."

• If the PoE interface is not enabled with the PoE power management function, you cannot enable PoE for the PoE interface.

• If the PoE interface is enabled with the PoE power management function, you can enable PoE for the PoE interface. Whether the PDs can be powered depends on other factors, such as the power supply priority of the PoE interface.

The PSE supplies power over category 3/5 twisted pair cable for a PoE interface in the following modes:

• Over signal wires—The PSE uses data pairs (pins 1, 2 and 3, 6) to supply DC power to PDs.

• Over spare wires—The PSE uses spare pairs (pins 4, 5 and 7, 8) to supply DC power to PDs.

When the sum of the power consumption of all powered PoE interfaces on a PSE exceeds the maximum power of the PSE, the system considers the PSE as overloaded. The maximum PSE power is user configurable.

A PSE can supply power to a PD only when the selected power supply mode is supported by both the PSE and PD. If the PSE and PD support different power supply modes (for example, the PSE does not support power over spare wires, while the PD supports power over spare wires), you have to change the order of the lines in the twisted pair cable to supply power to the PD.

The switch's PoE interfaces can supply power only over signal wires.

To enable PoE for a PoE interface: