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The last time was the resistance of the network cable when the power supply distance was 100 meters, which is the available power at the maximum power supply distance, but if the actual power supply distance is relatively small, such as only 10 meters, then the resistance is only 2 ?, The corresponding loss is only 10% of the loss of 100 meters, so it is important to fully consider the actual situation when selecting PSE equipment.
100m resistance of super five types of twisted-pair cables of various materials:
1. Copper clad steel network cable: 75-100?
2. Copper clad aluminum network cable: 24-28?
3. Copper-clad silver network cable: 15?
4. Copper-clad copper network cable: 42?
5. Oxygen-free copper network cable: 9.5?
It can be seen that the better the cable, the smallest the resistance, according to the formula Q = I²Rt, that is, the least power loss during the power supply process, so this is the reason why the cable is used well, it is recommended to use a more stable type 6 cable .
We have mentioned above, the loss power formula, Q = I²Rt. In order for the poe power supply to have the least loss between the PSE power supply end and the PD power receiving device, the minimum current and minimum resistance are required to make the entire power supply process work well.