NEWS CENTER

Shenzhen JHA Technology Co., Ltd is one of the leading manufacturers of hardened Ethernet, PoE, and fiber connectivity products specifically designed for harsh and demanding environments.


18

2022

-

11

The reasons why the PoE power supply is not stable


The problem may be the transmission distance of the network cable or the poor contact of the crystal head of the network cable. I have encountered this situation many times before. Basically, it can be solved by changing the crystal head or changing the network cable again.

The transmission distance of POE power supply is theoretically 100 meters, but cannot exceed 80 meters in practical applications

POE power supply is referred to as LAN-based power supply system or Active Ethernet, and is sometimes referred to simply as Power over Ethernet. It refers to the technology of providing DC power supply while transmitting network data signals for some IP terminal devices (such as network cameras, etc.) through a network cable. Therefore, Poe power supply transmission requires high quality of network cables, at least the network cables of super five types of oxygen-free copper must be selected.

POE power supply uses network cables to transmit power and data signals. The transmission distance of ordinary super-category 5 network cables is theoretically about 100 meters, but in order to ensure the actual use effect, it is generally recommended to be about 80 meters.

POE power supply and transmission are unstable. Consider the transmission distance of the network cable. If the distance of the network cable is too long, the POE cascade method must be used.

The connection method of the network cable crystal head must be standard

Due to POE power supply and transmission, the production requirements of the network cable crystal head are very high, and 8 network cables must be connected in accordance with the standard line sequence, and all of them must be connected. If the metal piece of the crystal head is in poor contact, it is particularly easy to cause unstable POE power supply.

And the network cable connection method must be installed by the standard T-568A: 1-green-white 2-green 3-orange-white 4-blue 5-blue-white 6-orange 7-brown-white 8-brown. T-568B: 1-orange-white 2-orange 3-green-white 4-blue 5-blue-white 6-green 7-brown-white 8-brown. The network cable should preferably be made of oxygen-free copper. The transmission resistance of oxygen-free copper network cable is small. The resistance of 100 meters is about 9.5Ω. The higher the resistance, the worse the quality of the network cable.

To sum up, the reason why the power supply of the POE switch is unstable is due to the poor contact of the crystal head or the poor quality of the crystal head. It is best to make a new crystal head.

undefined

undefined