In the broad sense, wires and cables are also referred to as cables. In the narrow sense, cables refer to insulated cables, which are composed of the following parts:; One or more insulated cores, as well as their respective possible covering layers, total protective layers and outer protective layers. The cable may also have additional uninsulated conductors.

　　There are copper core cables and new aluminum alloy aluminum core cables. The following is a brief introduction to the differences between the two.

　　1、 Product characteristics of copper core cable:

　　1. Low resistivity: the resistivity of aluminum core cable is about 1.68 times higher than that of copper core cable.

　　2. Good ductility: the ductility of copper alloy is 20-40%, that of electrical copper is more than 30%, and that of aluminum alloy is only 18%.

　　3. High strength: the allowable stress under normal temperature is 7 ~ 28% higher than that of aluminum. Especially the stress under high temperature, the difference between the two is very far.

　　4. Fatigue resistance: aluminum is easy to crack after repeated bending, while copper is not. In terms of elastic index, copper is about 1.7-1.8 times higher than aluminum.

　　5. Good stability and corrosion resistance: copper core is oxidation-resistant and corrosion-resistant, while aluminum core is easily oxidized and corroded.

　　6. Large current carrying capacity: due to low resistivity, the allowable current carrying capacity (maximum current that can be passed) of copper core cable with the same section is about 30% higher than that of aluminum core cable

　　7. Low voltage loss: due to the low resistivity of copper core cable, when the same current flows through the same section. The voltage of the copper core cable is small. Therefore, the same transmission distance can ensure high voltage quality; In other words, under the allowable voltage drop condition, the copper core cable transmission can reach a relatively long distance, that is, the power supply coverage area is large, which is conducive to the network planning and reduces the number of power points.

　　8. Low heating temperature: under the same current, the heating capacity of copper core cable with the same section is much smaller than that of aluminum core cable, which makes the operation safer.

　　9. Low energy consumption: due to the low resistivity of copper, compared with aluminum cable, the power loss of copper cable is low, which is obvious. This is conducive to improving the utilization rate of power generation and protecting the environment.

　　10. Oxidation resistance and corrosion resistance: the connector of copper core cable has stable performance and will not cause accidents due to oxidation. The joint of aluminum core cable is unstable, and the contact resistance is often increased due to oxidation, resulting in heating and accidents. Therefore, the incident rate is higher than that of copper core cable

　　Much more.

　　2、 Product characteristics of aluminum core cable:

　　1. Low price: the price of copper pole is 3.5 times that of aluminum pole, and the proportion of copper is 3.3 times that of aluminum. Therefore, aluminum core cable is much cheaper than copper core cable, which is suitable for low-cost projects or temporary power consumption.

　　2. The cable is very light: the weight of aluminum core cable is 40% of that of copper core cable, and the construction and transportation costs are low.

　　3. Oxidation resistance and corrosion resistance: aluminum reacts with oxygen in the air to form an oxide film, which can avoid further oxidation. Therefore, aluminum conductor is the necessary material for high-voltage, large-section and long-span overhead transmission. Although aluminum core cable is cheap, copper cable has outstanding advantages in cable power supply, especially in underground cable power supply. The underground use of copper core cable for power supply has the characteristics of low accident rate, corrosion resistance, high reliability and convenient construction protection. This is also the reason why copper cables are mainly used in underground cable power supply in China.