Copper vs. Aluminum Cables: Pros and Cons

Copper and aluminum cables are the two most commonly used conductor materials in power transmission. They each have their own unique characteristics in terms of conductivity, mechanical properties, cost, and service life, making them suitable for different applications. Below is a detailed comparison of the two:
Advantages of Copper Cables
Copper has excellent electrical conductivity, with an electrical conductivity approximately 1.6 times that of aluminum. This means that for the same cross-sectional area, copper cables have lower electrical resistance, lower power loss, and higher transmission efficiency. Therefore, for the same current carrying capacity, copper cables can be constructed with smaller cross-sections, saving space and facilitating conduit routing and installation.
Copper has high mechanical strength, excellent tensile and bending resistance, and is resistant to breakage, making it suitable for applications subject to frequent movement or high vibration, such as equipment power cables and drag chain cables. Furthermore, copper's high ductility allows for secure crimping of connectors, low contact resistance, and resistance to loosening or heat generation over long periods of operation, resulting in highly reliable connections
Copper is chemically stable and resistant to oxidation. Even if an oxide layer (copper oxide) forms on the surface, it retains a certain degree of conductivity without significantly affecting the electrical connection. This ensures stable operation of copper cables in humid, hot, or corrosive environments. Furthermore, copper-core cables have a long service life, typically exceeding 30 years, and offer low maintenance costs, making them suitable for applications requiring high safety and reliability.

Disadvantages of Copper-Core Cables

The biggest disadvantage is their high cost. Copper is much more expensive than aluminum, typically three to five times that of aluminum. This results in a higher overall cost for copper-core cables, especially in large-section, long-distance transmission projects.

Furthermore, copper's high density (approximately 8.9 g/cm³) makes the cables heavier, increasing the difficulty of transportation, hoisting, and installation. This is especially true for overhead lines or vertical wiring in high-rise buildings, which places higher demands on the supporting structure.

Advantages of Aluminum-Core Cables

The most prominent advantage is their low cost. Aluminum is abundant and inexpensive, making the use of aluminum-core cables significantly reduce initial project investment, making them particularly suitable for large-scale projects with limited budgets or long-distance transmission.

Aluminum has a low density (approximately 2.7 g/cm³) and is lightweight, weighing approximately 30% of copper. This makes aluminum-core cables easier to transport, hoist, and install, making them particularly suitable for weight-sensitive applications such as overhead lines, bridges, and towers. Disadvantages of Aluminum-Conductor Cables

Aluminum-conductor cables have poor electrical conductivity. To achieve the same current-carrying capacity as copper-conductor cables, the cross-sectional area of ​​the aluminum core must be approximately 1.6 times larger. For example, the current-carrying capacity of a 10mm² copper core is roughly equivalent to that of a 16mm² aluminum core. This results in a larger cable outer diameter, which occupies more space in cable trays or conduits.

Aluminum also has weak mechanical properties. Aluminum is soft and has low tensile strength, making it prone to breakage or deformation when bent or subjected to stress. It is not suitable for environments with frequent movement or vibration.

Poor connection reliability is a major concern for aluminum-conductor cables. The aluminum surface is highly susceptible to oxidation, forming a highly resistive aluminum oxide film. Improper joint preparation (such as loose crimping, failure to use specialized terminals or antioxidants) can easily lead to poor contact, localized overheating, and even fire. Therefore, aluminum-conductor cables require high joint craftsmanship and are difficult to install.

Furthermore, aluminum has a high coefficient of thermal expansion, making it prone to "creep" under hot and cold cycling, leading to loose connections and posing a safety hazard during long-term operation. Recommended Usage Scenarios

Copper-core cables are suitable for:

Internal power distribution in residential buildings (such as sockets, lighting, and distribution boxes);

Industrial equipment power cables and control cabinet wiring;

Vertical power supply trunks in high-rise buildings;

Applications requiring high safety and stability (such as hospitals, data centers, and fire protection systems);

Applications subject to movement or frequent bending (such as drag chain cables and welding machine cables);

Aluminum-core cables are suitable for:

Long-distance overhead transmission lines (such as rural power grids and urban trunk lines);

Main distribution lines for large factories and substations;

Cost-sensitive engineering projects;

Applications requiring fixed installations with few connection points and easy maintenance

Summary

Copper-core cables offer superior performance and safety, but are expensive and heavy. Aluminum-core cables are economical and lightweight, but have poor conductivity and high connection risks. In actual projects, the choice should be based on a comprehensive consideration of load requirements, installation environment, budget, and safety level. Copper-core cables are recommended for critical loads and indoor wiring; aluminum-core cables are more advantageous for large-span, low-cost outdoor power transmission. In recent years, "copper-clad aluminum" or "copper-aluminum transition terminals" have also been used to balance performance and cost, but the construction quality must be strictly controlled.