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Are you often unsure whether to choose copper cable or aluminum cable for your electrical project? Through this article, we will explore the technical characteristics and applications of each type of cable. From there, you will have an overview to make the most appropriate decision, ensuring both quality and safety while saving costs for each specific project.
1. Overview of copper and aluminum cables
Copper cables are electrical conductors made from copper metal, which has very high electrical and thermal conductivity. They are commonly used in residential and commercial electrical systems, electronic circuits, and power transmission.
Aluminum cables are electrical conductors that use aluminum as the primary material. They are lighter than copper and have a lower cost, often used in overhead power lines and some industrial applications.
2. Technical specifications of copper and aluminum cables
To make an appropriate decision, we need to clearly understand the basic technical characteristics of each type of cable.
2.1 Electrical conductivity and specific gravity
Electrical conductivity is the ability of a material to conduct electric current. The higher the conductivity, the lower the resistance of the material and the better it conducts electricity. Below is a comparison table of the electrical conductivity of copper and aluminum:
As we can see, the electrical conductivity of copper is about 1.6 times higher than aluminum. This means that a copper cable of the same size as an aluminum cable will have a better ability to transmit electric current.
However, the specific gravity of copper is nearly 3.2 times higher than aluminum, resulting in copper cables often being heavier and more expensive to transport and install compared to aluminum cables.
2.2 Mechanical strength and load-bearing capacity
Copper has a denser crystal structure than aluminum, so copper cables have high mechanical strength and are less prone to stretching or breaking. Meanwhile, aluminum cables are easily deformed under compression and tension. Moreover, when bent repeatedly or at high temperatures, aluminum can “creep” (slowly deform), reducing the cross-section of the conductor and affecting the ability to transmit electricity.
The tensile strength of copper ranges from 300 – 400 N/mm² for hard copper and 180 – 220 N/mm² for soft copper, while the tensile strength of aluminum ranges from 160 N/mm² for hard aluminum and 80 N/mm² for soft aluminum.
Thus, we can see that copper cables have a much higher tensile and bending strength than aluminum cables. This property makes copper cables more suitable for applications with high stress and vibration such as in construction and machinery.
2.3 Corrosion resistance and protection
When exposed to air, aluminum will form a thin, durable oxide layer that protects the surface from further corrosion. In contrast, copper is less resistant to corrosion, easily oxidized and forming carbonate compounds. Therefore, copper cables usually need to be covered with an insulating layer for corrosion protection.
2.4 Cost
Cost is an important factor influencing the choice of cable for each specific project. According to data from the London Metal Exchange, in February 2025, the market price of copper was 9,600 USD/ton, while the price of aluminum was only 2,608 USD/ton.
Thus, aluminum cables are often much cheaper than copper cables. However, in practice, because aluminum has lower electrical conductivity, larger cross-section aluminum wires must be used to transmit the same current, which increases the cost.
3. Applications of copper and aluminum cables
Copper and aluminum cables have many important applications in power transmission systems such as:
- Residential electricity: Copper cables are often preferred for use in residential electrical systems because of their high safety and durability. Copper wires are also easy to install, have good heat resistance, and are less affected by melting and burning.
- Overhead power lines: In remote areas requiring long power transmission lines, bare aluminum conductors (AAC) or aluminum conductor steel reinforced (ACSR) are often used to reduce weight and cost. Lightweight aluminum wires facilitate transportation and installation in difficult terrains.
- Underground cables in manholes and cable ducts: Copper cables have high mechanical strength and safety, making them suitable for running through manholes and underground cable ducts.
- Household and industrial electrical appliances: Copper cables are widely used in fan wires, power cords, equipment connection wires, electric motors… because copper has good conductivity, low loss and is stable with heat.
4. Guide to choosing the right cable
To select quality copper or aluminum cables that are suitable for the purpose and requirements of the application, pay attention to the following factors:
- Power transmission efficiency: For systems with high power, reliability and efficiency, prioritize using copper cables.
- Investment and operating costs: Calculate the total life-cycle cost of the project, including the cost of conductors, transportation, installation, operation and maintenance.
- Installation environment: Aluminum cables are lighter and more flexible but less durable than copper in harsh conditions.
- Choose cables that comply with domestic and international standards such as TCVN, ICE, ASTM, BS and current technical regulations on electricity.
- Select reputable brands in the market that have achieved quality certifications such as ISO or QUACERT to ensure quality.
5. Frequently asked questions (FAQs) about copper and aluminum cables
5.1 When should aluminum cables be used instead of copper cables?
Aluminum cables are suitable for long distance overhead power lines that need to reduce load and cost. However, when high electrical conductivity and efficiency are required, copper is still a better choice.
5.2 Should aluminum cables be used in residential electrical systems?
For residential electrical systems, especially branch circuits in the home, copper cables are still the safer, more reliable and widely recommended option compared to aluminum cables. Although aluminum wires may be cheaper in terms of material, there are greater risks in terms of fire safety and lower reliability. Electrical safety is always a top priority in residential electrical systems.
In some very specialized applications that are not common in residential use (for example, requiring maximum weight reduction), the use of aluminum wires may be considered but must be designed, installed and quality controlled extremely rigorously by experienced experts.
5.3 How to protect aluminum cables from corrosion?
In coastal areas or corrosive environments, aluminum cables are often coated with a layer of heat-resistant neutral grease on the surface of the aluminum wire to prevent corrosion. In addition, cables made from aluminum alloys are also widely used due to their good corrosion resistance.
Avoid direct contact of aluminum cables with soil, water, or other corrosive materials. Regularly inspect and replace cables showing signs of deterioration.
6. Conclusion
In summary, choosing copper or aluminum cables has its own advantages and disadvantages. While copper wires have high conductivity and good load-bearing capacity, aluminum wires have the advantage of weight and cost.
Each electrical project or construction will have its own requirements for functionality, operating conditions and investment budget. Therefore, to find the optimal solution, engineers and electricians need to carefully consider the technical characteristics as well as the specific application conditions.
If you are still unsure about choosing the right cable, don’t hesitate to consult experienced experts or reputable suppliers. They will advise and make specific recommendations to ensure your project operates safely and efficiently.
