Frequently asked questions about electrical cables

1.1 What are the difference between cables and wires

Although both wires and cables are vital components in electrical systems, they are not the same.

A wire is a single electrical conductor made of copper or aluminum. It can be solid or stranded (multiple twisted strands). Wires may be bare or insulated with color-coded sheaths. Wire sizes are typically measured using the American Wire Gauge (AWG) standard—lower AWG numbers mean thicker wires with higher current-carrying capacity.

A cable, on the other hand, consists of two or more insulated conductors bundled together and covered with an overall protective sheath. Cables usually contain hot (live), neutral, and ground conductors.

>>See more: What are AWG and AWG cables?

1.2 What are the components of an electrical cable?

A standard electrical cable typically includes:

• Conductor: The core component responsible for carrying current. It must have sufficient cross-sectional area to avoid overheating.
• Insulation: Surrounds the conductor, providing electrical resistance and thermal stability.
• Outer sheath: Protects against moisture, weather, chemicals, and mechanical damage.
  Additional layers may include shielding (to prevent EMI) and armor for mechanical protection.

>>Find out more: Features, components, and applications of electrical cables

1.3 What do the letters and numbers printed on electrical cables mean?

Cable markings are standardized abbreviations used to convey essential information about a cable’s technical specifications and areas of application. These markings may include the cable type, rated voltage, insulation and sheath materials, conductor cross-sectional area, and the number of cores.

Standardizing these designations ensures that users can accurately identify the cable’s specifications regardless of the manufacturer. This is particularly important for selecting and installing cables that meet safety and performance requirements in electrical systems.

Let’s take an example: H07RN-F 3G1.5 Each segment of this code has a specific technical meaning:

• H: Indicates this is a harmonized cable, manufactured in accordance with European standards.
• 07: Specifies a rated voltage of 450/750V.
• R: Denotes that the core insulation is made from ethylene-propylene rubber (EPR).
• N: Indicates the outer sheath is made from polychloroprene rubber (CR).
• F: Signifies a flexible cable made of fine stranded conductors, suitable for applications requiring high flexibility.
• 3: Represents the number of cores in the cable.
• G: Stands for “Ground,” indicating the presence of a green-yellow protective earth conductor.
• 1.5: Specifies that each conductor has a cross-sectional area of 1.5 mm².

2.1 What are the differences between solid wire and stranded wire?

Solid wire consists of a single, continuous metal core, whereas stranded wire is made up of multiple small strands twisted together to form a single conductor.

Stranded wire is composed of many thin wire strands compressed together and covered with an insulating, non-conductive sheath. Thanks to its flexibility and bendability, stranded wire is ideal for applications where frequent bending or complex routing is required — such as in printed circuit boards (PCBs) or in compact spaces.

In contrast, solid wire tends to be thicker and heavier. It is preferred for outdoor or fixed installations that demand high current capacity and long-term mechanical strength.

2.4 When should copper conductor cables be used, and when are aluminum conductor cables more suitable?

Thanks to its superior conductivity, copper is the primary material used in most electrical cables, as well as many electrical devices and components. Copper conductors are widely used in power transmission, power generation, and the automotive industry due to their excellent electrical performance.

However, aluminum is often preferred in overhead transmission lines by utility companies because it is more cost-effective and lighter than copper. These characteristics also make aluminum cables highly favored in industries where weight reduction is critical, such as aerospace and next-generation electric vehicles.

In some specialized applications - such as large-diameter coaxial cables, copper-clad aluminum (CCA) conductors are used. This material combines the high conductivity of copper with the light weight of aluminum, offering a balanced performance at lower cost and mass.

2.5 What is the difference between single-core and multi-core electrical cables?

A single-core cable (or single-conductor cable) contains only one conductive core surrounded by an insulating layer.

A multi-core cable (or multi-conductor cable) consists of multiple insulated conductors, each individually insulated and grouped together under a common outer sheath.

3.1 What materials are used for insulation and sheathing in electrical cables?

The most commonly used materials for cable insulation and sheathing are thermoplastics and thermosets.

• Thermoplastic materials can be softened when heated and molded into desired shapes. Once cooled, they retain their new shape. A key characteristic of thermoplastics is that they can be melted and reshaped multiple times without altering their fundamental structure.
• Thermosetting materials, on the other hand, can also be softened and shaped with heat—but only once. This is because during the shaping process, they undergo a chemical cross-linking reaction (polymerization), which makes them unable to melt again after setting.

3.2 When should XLPE-insulated cables be used?

PVC is the most commonly used material for cable insulation and sheathing due to its low cost and stable performance in most residential and general applications. However, in certain conditions, XLPE (Cross-linked Polyethylene) becomes the superior choice.

XLPE offers a higher maximum operating temperature—up to 90°C. This means that, when comparing XLPE-insulated cables and PVC-insulated cables of the same conductor size, XLPE cables can carry a higher current load.

Moreover, for the same current-carrying requirement, XLPE cables may allow the use of a smaller conductor cross-section than PVC cables—without compromising performance. This can help optimize the design and cost-efficiency of the electrical system.

The cross-linking process in XLPE enhances resistance to oil, chemicals, and thermal degradation, even at elevated temperatures. Thanks to these advantages, XLPE is commonly used in fire-resistant cables or LSZH (Low Smoke Zero Halogen) cables, where both electrical performance and safety are critical.

>>See more: A glance at XLPE material and XLPE-insulated cables

4.1 What is cable shielding?

Shielding (also known as a screen) is a metallic layer wrapped around an insulated conductor or group of conductors. While the structure may look similar in different cable types, the function of shielding varies depending on the application.

• In signal and electronic cables, shielding is primarily used to block electromagnetic interference (EMI) and prevent signal distortion.
• In power cables, shielding primarily protects users from electrical shock and helps prevent partial discharges (corona effect), thereby increasing cable reliability and safety.

Common types of cable shielding include foil shield, braided shield, spiral shield.

4.2 What is the role of cable armor?

In many installations, electrical cables are exposed to harsh mechanical stresses such as crushing, impacts, or pulling forces. If not properly protected, these forces can damage the insulated conductors or fiber optics inside the cable.

To address this, cables are often equipped with an armor layer—typically made of metal—wrapped over the cable core. This armor provides mechanical protection against external physical damage, extended cable lifespan, enhanced safety, and improved operational reliability in demanding environments.