What are the characteristics of aluminum electric wires such as coaxial cables? An easy-to-understand explanation

Aluminum electric wires are an important material used not only for coaxial cables but also for various electrical wiring. Aluminum electric wires are lighter and more economical than copper wires, and are used in a wide range of applications from industrial to household.

Therefore, in this article, we will explain in detail about the types, characteristics, advantages, and specific applications of aluminum electric wires for those who are interested in them. Please read to the end as a reference for selecting electric wires.

Not just coaxial cables! Types of aluminum wires

There are various types of aluminum electric wires depending on the application and required performance. By utilizing the characteristics of each type, efficient power transmission and signal transmission can be achieved. Here, we will explain the main types of aluminum electric wires and their characteristics.

Coaxial cables

Coaxial cables are electrical communication cables that are made up of four layers: an inner conductor, an insulator, an outer conductor, and an outer coating. There are three types of coaxial cables for television use: 4C, 3C, and 4C, with the larger the number, the thicker the cable. 5C is suitable for short-distance wiring of 3m or less, 3C for indoor wiring of 3 to 4m, and 5C for outdoor wiring of 10m or more.

Aluminum coaxial cables are approximately 30% lighter than copper ones. The use of aluminum foil for the outer conductor provides excellent shielding and low-loss signal transmission.

Steel core aluminum stranded wire

Steel core aluminum stranded wire is an electric wire with a steel strand placed in the center and surrounded by hard aluminum wire. This structure gives it both light weight and high mechanical strength. It weighs about one third as much as copper wire, yet has the same power transmission capacity.

The large outer diameter reduces the electric field strength and suppresses the occurrence of corona discharge, making it particularly suitable for high voltage transmission. In addition, the stranded structure makes it easy to handle and install, and contributes to improving transmission capacity and stability.

Aluminum alloy wire

Aluminum alloy wire is a highly functional conductive material made by adding other metal elements to pure aluminum. The world's highest standard products are more than twice as strong as existing products, and have high fatigue properties, connectivity, and formability.

It is characterized by its light weight, about one-third that of copper wire, and taking advantage of this light weight, it is widely used in applications involving movement, such as automotive wire harnesses, IoT devices, and robot-related wiring.

In addition, it has excellent workability, allowing it to be processed down to an extremely fine diameter of 44 μm, and is also characterized by its excellent corrosion resistance due to the formation of a stable oxide film on its surface. It is also known as a highly reliable material, as it is less susceptible to brittle fracture even in low-temperature environments.

Pure Aluminum Wire

Pure aluminum wire is a high-purity material with an aluminum purity of 99.5% or more. It is approximately one-third lighter than copper wire and is suitable for long-distance power transmission and distribution lines.

A dense oxide film of about 0.2 μm is naturally formed on the surface, and this protective layer provides excellent corrosion resistance, allowing it to be used without problems for over 30 years even in harsh environments such as near the coast.

It has excellent workability and weldability, and can be joined by TIG welding or laser welding. However, it has lower strength than general aluminum alloys, so it is not suitable for use as a structural member. Its main applications are electrical equipment frames, lighting fixtures, chemical industry tanks, and air conditioner heat exchangers.

Aluminum conductor plastic wire

Aluminum conductor plastic wire is an electric wire with an aluminum conductor covered with plastic insulation. It is about one-third the weight of copper wire, which contributes to the efficiency of wiring work.

The insulation is mainly made of fluororesin such as FEP and ETFE, which has excellent electrical properties as well as high heat and chemical resistance. In addition, the plastic insulation flexibly conforms to bending, making it easy to handle even in complex wiring routes.

Its main applications are in automotive wiring, electronic devices, and communication devices, which require lightweight construction.It is also used in high-temperature environments, as wiring for ammonia refrigerant peripheral devices, and as motor windings.

Characteristics of aluminum wire

Aluminum wire has different properties from copper wire. Understanding these properties will help you use aluminum wire appropriately.

The main feature of aluminum wire is its light weight, about one-third that of copper wire. It is also more flexible than copper, and can be bent with about half the force. Its thermal conductivity is about three times higher than that of steel, and it has excellent heat dissipation properties.

A naturally formed oxide film on the surface protects the inside of the wire. When compared by weight, it can carry twice as much current as copper wire, and has excellent electrical conductivity.

Advantages of aluminum wire

Aluminum electric wires offer a variety of benefits throughout their entire life cycle, from manufacturing to installation, operation and recycling.

Here are five main advantages of aluminum electric wires.

Cost-effective

Aluminum electric wires can achieve significant cost savings compared to copper electric wires. The material price is about 30-50% of that of copper, which is an advantage in reducing costs especially in large-scale electrical construction projects. In addition, aluminum electric wires are lightweight, which reduces labor costs for transportation and installation.

Since market prices are relatively stable, budget management is easy, and since there is a low risk of theft, it also leads to reduced security measures costs.

Excellent noise reduction performance

Aluminum coaxial cables use aluminum foil for the outer conductor, which effectively prevents external electrostatic induction and electromagnetic interference. It is possible to eliminate noise of over 0.1 dB over a wide frequency range of 1000 to 100 MHz, and a practical shielding effect can be obtained even with aluminum foil as thin as 10 µm.

Easy to handle and install

Aluminum wires are characterized by their ease of handling at construction sites. Their light weight (approximately one-third that of copper wires) and high flexibility greatly improve the efficiency of wiring work. This feature is a major advantage, especially when wiring in narrow spaces or along complex routes.

In terms of construction, cable delivery, drum unloading, movement, lifting, etc. can be carried out with less labor than with conventional copper wires. By optimizing the configuration of the aluminum conductor, we have achieved 1.5 times the flexibility of conventional products, significantly improving the efficiency of cable extension and terminal processing work.

Excellent corrosion resistance

Aluminum electric wires naturally form a dense and stable oxide film on their surface, which protects the aluminum inside. Although this film is an extremely thin layer of about 1 nm, it is extremely strong and chemically stable, so it maintains excellent corrosion protection even after long-term use for more than 30 years.

Furthermore, even if the oxide film on the surface is damaged, it has the ability to self-repair and instantly regenerate in an environment where oxygen is present. Also, by using a special alloy, it has 1.6 to 2 times the corrosion resistance compared to standard electric wires.

High recyclability

Aluminum has a low melting point and can be recycled with only 3% of the energy required to manufacture a new product, making it known as the "king of recycling."

Another feature of aluminum is that its quality hardly deteriorates during the recycling process, which means that almost 100% of the aluminum used as a conductor in electrical wires can be recycled, establishing an efficient resource circulation system.

Applications of aluminum wire

Applications that take advantage of the characteristics of aluminum electric wires are expanding into various fields of industry. Here we will introduce some representative applications and specific examples of their use.

Lighting circuits and power distribution

Aluminum electric wires are widely used in lighting circuits and power distribution systems in commercial buildings and apartment buildings. Branched trunk cables for tunnel lighting have branch wires pre-connected at specified intervals and molded insulation, achieving both high waterproofing and work efficiency.

Additionally, for low-voltage trunk lines in apartment complexes and office buildings, it is common to use "branched cables" in which branch wires are pre-connected at designated locations at the factory.

For power distribution, aluminum wires are available in a variety of sizes, from 32mm² to 120mm², and can be selected according to the application and required current capacity. In particular, in wiring systems for intelligent buildings, they are used as multi-core cables taking advantage of their low impedance characteristics, enabling advanced power control.

Powering machines and equipment

Aluminum electric wires also have excellent properties when supplying power to machine tools and industrial equipment. Their light weight makes installation more efficient and maintenance easier.

In addition, for large-capacity equipment such as transformers, the weight of the entire facility can be reduced by using aluminum for the windings, which reduces the load on the floor during installation and allows greater freedom in the structural design of buildings.

Solar Power Generation

Since mega solar power plants require long-distance wiring over vast sites, the properties of aluminum wires are a major advantage. The lightweight nature of aluminum conductors greatly improves work efficiency, and this is expected to reduce the number of workers and costs.

In recent years, efforts have been made to make aluminum conductors easier to distinguish from copper wires, such as by coloring the exterior of the aluminum conductor blue, which is also effective in preventing installation errors and theft.

Summary

Aluminum wires are attracting more and more attention as an alternative material to copper wires, with excellent properties and many advantages. By selecting the right type for each application and using the correct installation method, an economical and efficient wiring system can be realized. Technological innovation is expected to further improve performance and expand applications in the future.