Influence of Immersion on UTP of indoor Cables

Indoor cables, just as in their names, are cables made for indoor applications-that is, they cannot be immersed in liquid water in this environment. No more than outdoor cables, indoor cables do not use water-resistant materials or structures that reduce water penetration.

If the indoor cables are immersed in water, the cables may enter the water. Cable Entry will immediately lead to a negative impact on the electrical transmission characteristics of the cable, including capacitance, attenuation, crosstalk and balance. In the long term, the cable entry will also lead to corrosion of copper conductor and various insulation problems.

These problems apply to any indoor cable and are especially critical for High-Performance Network cables of category 5 and Category 6. If the cables in the room are immersed in water, the high performance of cat5e and cat6 Cables cannot be guaranteed.

Communication Cable immersion

With the increasing application of high-speed data services, indoor cable loading becomes an important issue. The effects of Immersion on indoor cables are as follows:

Conductor Corrosion

Increase in capacitance and Attenuation

Reduced Characteristic Impedance

Corrosion: In severe cases, the wires in the immersed cables may be broken. The plastic used for cables is as porous as any other plastic material. Water can penetrate into the cable through the outer skin of the cable. When there is a current, the working line will produce a potential difference between the water penetration of the Porous Plastic Insulator and the conductor contact, the electronic will move through the conductive water. After a period of time, the water will become a dilute sulfuric acid solution. The copper core of the wire and the outer plating layer will produce electrolysis, which will corrode the copper core and lead to an open circuit. Capacitance and attenuation: Capacitance refers to the ability to store charge between cables and conductors when there is a potential difference between cables. The smaller the cable capacitance, the better the signal transmission quality. Because the capacitance increases with the length of the cable, the smaller the capacitance at the start of the cable, the longer the signal transmission distance.

Both capacitors and resistors are inherent characteristics of cables and cannot be eliminated. Only the negative effects of these cables can be minimized. The attenuation of high-frequency signals is much higher than that of low-frequency signals. The resistance and humidity of the copper cables have little impact on the cables. The water entry of the cables has a great impact on the capacitance between cables, even if a small amount of water is distributed on a cable, it will also increase the wire-to-Peer capacitance by several percentage points. If a cable enters the water, the capacitance between cables will be twice the nominal value. Cable entry does not significantly damage audio signal transmission, but it may cause unacceptable error rates for data transmission over cat5e. Attenuation refers to the signal weakening during transmission. It increases with the increase of capacitance and signal frequency. Of course, the smaller the value, the better. Therefore, immersion cables increase the attenuation of cables.

Characteristic Impedance: The Characteristic Impedance defines the relationship between voltage and current at any point on the cable. The high or low characteristic impedance is not good or bad for itself. However, when the data cable matches with other components, the special impedance becomes an important factor. If the characteristic impedance of the cable Pair does not match the characteristic impedance of the connected component, the echo reflection of the signal is generated. Water vapor in the cable reduces the characteristic impedance, resulting in mismatch between the cable and the connector, resulting in the generation of the echo signal.

Conclusion

Based on Avaya Lab tests, the high-speed data signal transmission quality of cat5e and cat6 Network cables will be unqualified due to the large amount of incoming cables. The conclusions are summarized as follows:

More error codes are generated when the immersed cable is added due to crosstalk.

When the length of the immersed cable segment exceeds a certain length, the whole system cannot pass the test due to excessive attenuation.

The characteristic impedance of the immersed cable is smaller than that of the dry cable.

The echo reflection caused by the immersed cable will generate more codes.

Therefore, we recommend that you replace all indoor cables soaked in floods. Cat5e and cat6 cables are commonly used in high-performance and important network links. If they cannot be replaced in time, unpredictable data loss or even network paralysis may occur.

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