Types of Wires and Their Classification

Types of Wires and Their Classification

The safe and efficient operation of electrical and electronic systems greatly depends on choosing the right type of wire. Since wires are responsible for transmitting electricity and signals, it is essential that their material, insulation, cross-section, and intended use match the needs of the application. In this article, we will look at the main ways to classify wires and explain when each type is best used.

Classification by Application

Based on their function and the level of stress they must withstand, wires can be grouped into power transmission cables, communication cables, and installation wires. This helps explain why a different type of cable is needed for a high-voltage power line compared to the wiring inside a building.

Power Transmission Cables: Designed specifically for carrying high-voltage electricity, such as in overhead power lines. They are made from materials and structures that can withstand weather conditions and long-term mechanical stress, such as wind, ice, and temperature changes.

Communication Cables: Used for telephone and data transmission, including coaxial cables and optical fibres. Here, minimising interference and maintaining signal quality is critical.

Electrical Installation Wires: Common in households, buildings, and offices, these wires deliver mains electricity to sockets and lighting circuits. Flexibility, safety features, and standard colour codes are especially important for this type.

Classification by Material

The performance and efficiency of wires are strongly influenced by the material used. The most common materials are copper and aluminium, with glass fibre (optical) cables used in special cases.

Copper Wires: One of the best electrical conductors, with high conductivity and good flexibility. This is why copper wires are most common in both household and industrial use.

Aluminium Wires: Lighter and cheaper than copper but with lower conductivity. Still, they are attractive for large cross-section cables, especially in long-distance power transmission, where weight is an important factor.

Optical Cables: Instead of conducting electricity, these carry light through glass fibres. They are mainly used for data communication, offering high transmission speeds and interference-free connections.

Classification by Insulation Type

Proper insulation is essential for safety and durability. Different insulating materials have different heat and mechanical resistance properties.

PVC (Polyvinyl Chloride) Insulation: Cost-effective and suitable for general purposes, such as home and office installations. It has moderate mechanical and heat resistance.

XLPE (Cross-linked Polyethylene) Insulation: Excellent heat and mechanical resistance, often used in industrial and high-voltage applications. It tolerates high temperatures and moisture better.

Rubber Tape Insulation: Flexible and strong, mainly used in outdoor and industrial environments where extra impact or pressure resistance is needed.

Location and Environmental Requirements

When installing wires, the physical environment, as well as temperature and mechanical stress, are just as important as current or voltage levels.

Indoor Wires: Do not require special UV or water protection. They are usually run inside walls, conduits, or cable channels.

Outdoor Wires: Equipped with weatherproof insulation and UV- and water-resistant coatings to withstand sunlight, rain, and extreme temperatures.

Underground Cables: Have stronger mechanical and chemical protection to endure soil movement, moisture, and pressure.

Special Features: Fire Resistance and Flexibility

Fire-resistant Cables: Contain materials that can withstand high temperatures and do not spread flames. They are essential in buildings, hazardous facilities, or escape routes.

Flexible Cables: Have highly flexible, stranded cores suitable for moving machinery parts or places where frequent bending is required.

Flexibility and Durability

When choosing a wire, two key factors are flexibility and durability. Flexibility is important in moving equipment, machine tools, or robot arms, while durability, meaning mechanical protection and wear resistance, is crucial in industrial environments with harsh conditions, strong vibrations, or heavy mechanical loads.

Colour Coding and Markings

Colour codes and markings help electricians and maintenance workers during installation and troubleshooting. According to European standards, the colours are:

• Phase: brown, black, or grey

• Neutral (N): blue

• Protective Earth (PE): yellow-green

In addition, cable markings usually show the manufacturer’s name, cable type, material, cross-section, and other details to help choose the right wire for a specific job.

Special Environmental Needs

Heat- and Fire-resistant Wires: Needed in high-temperature or fire-risk environments, with heat-resistant sheathing.

Chemically Resistant Cables: Used in industrial environments where they may be exposed to acids, alkalis, or other corrosive substances, requiring special coatings.

Safety and Standards - What to Watch For

When choosing a wire, performance is important, but so is compliance with safety regulations. Local building codes, relevant standards, and future expansion plans can all determine which cable design is needed. A cable with too small a cross-section can overheat and cause a fire, while poor insulation can result in electric shock or equipment damage.

The right wire not only improves efficiency and reliability but also reduces long-term maintenance costs by preventing failures and ensuring stable operation.

Conclusion

Understanding the different types of wires is essential for building a safe and efficient electrical system. Whether it’s for power transmission, communication, household wiring, or extreme environments, the material, insulation, and cross-section must suit the project’s needs. Following standards, using proper colour coding, and consulting a professional all help ensure that the system works reliably and maintains performance and safety over time.

If you are unsure which wire is best for a given task, it’s worth asking an expert who can recommend the right type based on load, environmental factors, and standards. This way, you can avoid future breakdowns and save both time and money with a well-designed electrical network.