《Research on Temperature Rise Characteristics of Data Cable with DC Power Supply》Received the First Prize in the 2024 (43rd) Communication Line Academic Annual Conference of the CIC

From September 4 to 6, 2024, the 2024 (43rd) Communication Line Academic Annual Conference of the China Society of Communications was held in Weihai, Shandong Province，China. The paper 《Research on Temperature Rise Characteristics of Data Cable with DC Power Supply》which was jointly accomplished by Dr. Fang He (the chief expert of Zhaolong Interconnect Connection System),  Zhou Qinyang and Shen Jintao from Dr. He’s team, received the first prize during the conference.

In this research, a temperature rise model of the data cable under DC power supply was constructed, and the temperature rise of the data cable carrying DC current was tested in detail through experiments. The influence of the conductor diameter and shielding structure on the cable temperature rise was revealed. Specifically, the cable with a thicker conductor diameter had a lower temperature rise than that with a thinner conductor diameter, and the cable with a shielding structure had a lower temperature rise than that without a shielding structure. Based on these findings, the paper investigated the application scenarios of Power over Ethernet(PoE) with different power requirements and provided specific specification suggestions for data cables and jumpers, offering guidance for integrated cabling under Power over Ethernet applications and promoting the development of the industry.

Here is an overview of the main content of the article:

Temperature Rise Model for DC Power Supply of Data Cable

In this study, a temperature rise model for the DC power supply of data cables was established. It was pointed out that when data cables were bundled and installed for remote power supply, the heat dissipation of the inner cable of the wire harness was blocked, and the temperature rose to a new heat exchange equilibrium.

Analysis of Cable Temperature Rise Characteristics

According to our tests and analyses, the temperature rise of the shielded structure cable was lower than that of the unshielded cable of the same specification, and the temperature rise of the thick-diameter cable was lower than that of the thin-diameter cable.

FIG. 14 Comparison of Temperature Rise Curves of Cables in Ventilation Environment

(From left to right: Class 5e U/UTP 0.45 mm, Class 5e U/UTP 0.5 mm, Class 6 U/UTP 0.53 mm, Class 6 U/UTP 0.57 mm, Class 6 U/UTP 0.55 mm, Class 6A U/UTP 0.565 mm, Class 6A U/FTP 0.57mm, Class 6 F/UTP 0.565mm, Class 7A S/FTP 0.58mm, Class 7 S/FTP 0.56mm, Class 8.1 S/FTP 0.595mm)

FIG. 15 Comparison of Cable Temperature Curve

(From left to right: Class 5e U/UTP 0.45 mm, Class 5e U/UTP 0.5 mm, Class 6 U/UTP 0.53 mm, Class 6 U/UTP 0.57 mm, Class 6A U/UTP 0.565 mm, Class 6 F/UTP 0.565 mm, Class 6A U/FTP 0.57mm, Class 7 S/FTP 0.56mm, Class 8.1 S/FTP 0.595mm)

Effect of Cable Temperature Rise on Performance

The temperature rise of the cable would affect the conductor resistance and insertion loss. Therefore, it is necessary to verify whether the channel insertion loss meet the standard limit at high temperatures for remote power supply.

Figure 22 Conductor Resistance Measurements of Cables at Different Levels

As can be seen from the figure, the conductor diameter is an important factor affecting the conductor resistance value, and the larger the diameter, the smaller the resistance.

Figure 23 Conductor Resistance Measurements for Cables in Different Working Areas

Figure 26 Insertion Loss of Class 6A U/FTP Cable under Different Temperature Conditions

FIG. 30 Relationship between Cable Length and Number of Bundling (PoE Type 4, 20 ℃ Ambient Temperature, Ventilation Environment)

FIG. 31 Relationship between Cable Length and Number of Bundling (PoE Type 4, 20 ℃ Ambient Temperature, Closed Casing Environment)

Summary of Research on Cable Temperature Rise

This paper verified the temperature rise of different data cables under DC power supply through tests and analyzed the temperature rise characteristics of Power over Ethernet. It was concluded that the cable with a thick diameter and a shielding structure had a low temperature rise. In the current cabling industry's pursuit of low cost and small diameter trends, the effect of cable temperature rise needs to be considered. For the scenario with the highest power requirement (Power over Ethernet Type 4), it is recommended to use a Class 6A shielded data cable with a conductor diameter of no less than 0.56mm for horizontal cabling and a specific Class 6A shielded jumper for workspace cabling. For higher power requirements (Power over Ethernet Type 3), the above-mentioned Class 6A or higher cables and shielding jumpers could be used, and specific Class 6 cables and jumpers could also be considered. In scenarios with low power requirements (Power over Ethernet Type 1 and 2), no special recommendation was made for cable layout. However, cables with conductor diameters smaller than 0.45mm are not recommended for horizontal cable layout.

Zhaolong will take this award as an opportunity to continue innovating in the field of wire and cable and integrated wiring, provide strong support for the development of the industry, and contribute its own strength to China's digital construction.