3Com 4500G Family Configuration Manual page 1088

The priority of the PoE interface is already set.
Solution:
In the first case, you can solve the problem by increasing the maximum PSE power, or by reducing
the maximum power of the PoE interface when the guaranteed remaining power of the PSE cannot
be modified.
In the second case, you should first remove the priority already configured.
Symptom 2: Applying a PoE configuration file to a PoE interface fails.
Analysis:
Some configurations in the PoE configuration file are already configured.
Some configurations in the PoE configuration file do not meet the configuration requirements of the
PoE interface.
Another PoE configuration file is already applied to the PoE interface.
Solution:
In the first case, you can solve the problem by removing the original configurations of those
configurations.
In the second case, you need to modify some configurations in the PoE configuration file.
In the third case, you need to remove the application of the undesired PoE configuration file to the
PoE interface.
Symptom 3: Provided that parameters are valid, configuring an AC input under-voltage threshold fails.
Analysis:
The AC input under-voltage threshold is greater than or equal to the AC input over-voltage threshold.
Solution:
You can drop the AC input under-voltage threshold below the AC input over-voltage threshold.
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