Electrical Cable Types, Sizes, and Installation

Electrical cables are essential components that transport electrical energy from one point to another safely and efficiently. Their construction, voltage capacity, insulation, and protective features determine where and how they can be installed. This guide explores the main types of electrical cables, their voltage categories, insulation materials, protective layers, and color codes—helping you choose the right option for your project.

Understanding Electrical Cable Voltage

Electrical cables are categorized by the voltage they are designed to handle. Voltage classification determines how and where a cable can be safely installed—from residential wiring to industrial power transmission.

Low Voltage Cables (up to 1,000 V)

Also known as 0.6/1 kV cables, these are commonly used in industrial power installations, public infrastructures, and general construction projects. Manufactured to international standards such as IEC, UNE, BS, and UL, low-voltage cables are versatile and designed for safe power transmission in buildings and public facilities.

Medium Voltage Cables (1 kV to 36 kV)

Medium-voltage cables distribute electricity from substations to transformers or large-scale industrial systems. Their insulation and construction allow them to handle higher power demands while maintaining safety and reliability.

High Voltage Cables (above 36 kV)

High-voltage cables are used to transmit electricity from generating plants to substations over long distances. Their insulation systems are engineered to withstand extreme electrical stress and environmental exposure.

Low Voltage Cable Types

Cables for Electric Panels

These flexible cables are designed for wiring electrical cabinets, switch boxes, and domestic installations. They are suitable for public buildings and small appliances, offering flexibility and flame-retardant insulation for added safety.

Power Cables

Used in low-voltage connections for industrial and commercial applications, power cables are engineered for energy transmission in machinery, distribution systems, and variable frequency drives (VFD).

Armoured Cables

Armoured cables are reinforced with steel wire armor (SWA) or aluminum wire armor (AWA) to resist mechanical impact, rodent damage, and other external stresses. They are ideal for underground or industrial installations where durability is critical, including ATEX (explosive-risk) environments.

Halogen-Free Cables

Low Smoke Zero Halogen (LSZH) cables emit minimal smoke and toxic gases during a fire. These are preferred in public places, emergency circuits, and densely populated buildings where fire safety is paramount.

Fire-Resistant Cables

Designed to maintain electrical integrity during prolonged fires, fire-resistant cables ensure the continuous operation of essential systems like alarms, smoke extractors, and emergency lighting. They are ideal for hospitals, tunnels, and evacuation pathways.

Control Cables

Flexible and designed for signal or power transmission in fixed or mobile installations, control cables are used in automation systems, machinery, and motor connections. Shielded variants prevent electromagnetic interference (EMI), ensuring precise signal control.

Instrumentation Cables

Shielded instrumentation cables are used for signal and data transmission in industrial plants. Their construction minimizes interference, providing accurate readings and reliable performance in high-EMI environments.

Solar Cables

Solar cables are optimized for photovoltaic (PV) systems. Their UV- and weather-resistant jackets withstand prolonged outdoor exposure, connecting panels to inverters safely and efficiently.

Aluminium Cables

Lightweight and cost-effective, aluminum cables are commonly used for power distribution in indoor, outdoor, and underground installations. They are especially suitable for long runs where reduced weight is advantageous.

Types of Insulation for Electrical Cables

Insulation prevents current leakage and enhances safety. Cable insulation materials are broadly classified into two groups—thermoplastic and thermosetting—depending on their heat resistance and flexibility.

Thermoplastic Insulation

Common materials include:

• PVC (Polyvinyl Chloride): Economical and durable, widely used in general applications.

• PE (Polyethylene): Excellent dielectric strength, ideal for data and coaxial cables.

• PU (Polyurethane): Resistant to oil, moisture, and abrasion, suitable for industrial cables.

Thermosetting Insulation

These materials resist deformation at high temperatures:

• EPR (Ethylene Propylene Rubber): Flexible and heat-resistant for industrial power cables.

• XLPE (Cross-Linked Polyethylene): High-performance insulation for medium and high-voltage cables.

• EVA (Ethyl Vinyl Acetate): Durable and weather-resistant for outdoor use.

• Silicone: Used in high-temperature environments.

• Neoprene (PCP) & SBR Rubber: Excellent mechanical and weather resistance for heavy-duty applications.

Types of Metal Protections for Electrical Cables

Metallic protections enhance cable performance and safety in demanding conditions.

• Screens: Metallic shields that block external electromagnetic interference, ensuring signal integrity in instrumentation and control cables.

• Armours: Mechanical protection layers made of steel or aluminum, safeguarding cables against impact, crushing, or rodent damage.

Three-Phase Cable Colour Codes (BS Standard)

Three-phase wiring color codes help ensure consistency and safety in electrical installations. In March 2006, the UK updated its standards to harmonize with European practices.

 

When working with existing installations, always verify the color code system before connecting to avoid phase mismatch or electrical hazards.

Choosing the Right Electrical Cable

When selecting an electrical cable, consider:

• Voltage and current rating – match to system requirements.

• Environmental conditions – choose UV-, water-, or flame-resistant materials as needed.

• Flexibility and mechanical protection – use armored or reinforced designs for industrial or underground work.

• Compliance – ensure standards like IEC, BS, and UL are met for safety and performance.

Conclusion

Electrical cables play a vital role in safely transmitting power and signals across various applications. From low-voltage domestic wiring to high-voltage transmission systems, selecting the right cable type and insulation ensures long-term efficiency and safety. At EYBY Marketplace, we supply a complete range of certified electrical cables—from control and solar cables to armored and fire-resistant types—designed to meet modern performance and safety standards.

Frequently Asked Questions

1. What are low-voltage cables used for?
Low-voltage cables power lighting systems, machinery, and general electrical installations up to 1,000 volts.

2. What is the difference between SWA and AWA cables?
SWA (Steel Wire Armoured) is used for multi-core cables, while AWA (Aluminum Wire Armoured) is used for single-core cables to prevent magnetic interference.

3. What are LSZH cables?
Low Smoke Zero Halogen cables minimize toxic gas and smoke emissions in fires, ideal for public and enclosed spaces.

4. Can I use aluminum cables for indoor installations?
Yes. Aluminum cables are lightweight and suitable for both indoor and outdoor applications if properly rated and installed.

5. Why are insulation materials important?
Insulation protects conductors from short circuits, heat, and external factors, ensuring cable safety and durability.

 

Disclaimer:
The information in this article is intended for general reference. Always verify electrical specifications and installation standards with a certified engineer or relevant regulatory authority before application.