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There is voltage reduction due to line impedance in 250 meter cable for PoE. What should I do?


Make sure your POE switch is connected to a 57V power supply so the powered device can get the full 25W after the 250M voltage reduction.
PoE output power table:

Input Voltage Output Power After 250m Voltage Power
57V 34.2W 42.93V 25.758W
55V 33W 40.93V 24.558W
53V 31.8W 38.93V 23.358W
51V 30.6W 36.93V 22.158W

(Base on CAT-5e cable)