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Aerial Insulated Cables are a specialized type of power distribution cable designed for overhead installation. Unlike traditional bare conductors that rely solely on air for insulation, aerial insulated cables feature one or more layers of insulation extruded over the conductor, providing a physical barrier that enhances safety, reliability, and environmental compatibility.
What Are Aerial Insulated Cables?
An Aerial Insulated Cable is a wire with a single or multiple layers of aluminum stranded wire twisted together, over which an insulation layer is extruded. The term “overhead line” refers to a line where conductors are erected on towers or poles at a certain height to transmit electrical energy. For high-voltage transmission and distribution networks, ground insulation generally relies on air.
Previously, bare conductors were commonly used for distribution lines (except for 380V below 10kV). However, due to the complex distribution environment in urban areas, short circuit grounding and lightning strikes often occur on the lines, resulting in decreased power supply reliability. Therefore, insulated conductors—with insulation layers wrapped around the outer layer of the conductors—are now generally used for overhead lines below 10kV.
The concept of insulated aerial cables was developed in the early 1960s in Europe to provide a reliable, safe, and economical alternative system of electrification. Today, aerial insulated cables are widely used in urban areas, high-rise residential and commercial districts, forested regions, and other settings with stringent safety requirements, as well as in areas where enhanced power supply reliability is essential.
How Do They Differ from Ordinary Cables?
The fundamental distinction lies in their application and construction. Ordinary power cables are designed for underground burial or indoor fixed installation, where the cable is protected by soil, conduit, or building structures. Aerial insulated cables, by contrast, are engineered for overhead suspension between utility poles or pylons.
As aerial cables are completely insulated, there is no danger of electric shock when touching them, and there is no requirement for mounting them with insulators on pylons and poles. A further advantage is that they require less right of way than overhead lines for the same reason. If the cable falls, it may still operate if its insulation is not damaged. As aerial cables are installed on pylons or poles, they may be cheaper to install than underground cables, as no work for digging is required—which can be very expensive in rocky areas.
Another critical difference is the messenger wire in bundled configurations. In traditional bare conductor systems, the current-carrying conductor bears all the tension. In an aerial bundled cable (ABC), a separate messenger wire takes up the bulk of the tensile stress, allowing the conductor to operate at 90°C compared to 75°C for a bare conductor under tension. This allows ABC to carry current equivalent to that of a bare conductor of the same size.
Key Advantages of Aerial Insulated Cables
1. Enhanced Safety and Reliability
There is no risk of power outage caused by falling trees or birds causing short circuit as compared to bare lines. Risks of direct lightning strikes are also greatly reduced compared with bare wire lines, as the fully insulated cable does not attract lightning strikes, and indirect strikes cause no damage to cables.
Conventional bare line systems are prone to short circuits due to clashing conductors, whereas the fully insulated system comprises one fully insulated cable and therefore completely eliminates this problem. Tests on the Shetland Islands and installations in Norway have proven that galloping and vibration are not a problem with fully insulated systems.
2. Lower Maintenance Costs
As a result of the above advantages, fewer repair call-outs are required for the fully insulated cable system, and there is a reduced number of difficult repair and clearing line jobs. Emergency call-outs are not needed, and clearing of lines can be performed during normal working hours.
3. Space Efficiency and Route Flexibility
Insulated or covered lines are well suited for urban environments because they require smaller way leaves and servitudes and can hence accommodate encroaching buildings to a greater degree than uncovered lines. This may have a cost advantage for existing lines over burying the lines. In rural areas, changes in the use of servitudes of existing overhead lines using uncovered conductor may necessitate the use of covered conductor to avoid having to obtain a new servitude—for example, where relatively low crops are replaced by trees.
4. Environmental Resilience
Aerial insulated cables are designed to withstand extreme weather conditions without power interruption. The unique design can handle ice loads, storms, and snow-laden trees. The self-supporting conductors take up the bulk of the tensile stress, and forces from a falling tree are propelled through the cable sheath and insulation into the supporting conductor without damaging the cable. This reduces repair downtime in comparison with other systems—resulting in less repair call-outs and smooth maintenance.
5. Cost-Effectiveness
The fully insulated aerial cable system offers lower total cost of ownership than air-insulated bare lines by reducing costs for right of way, building, and maintenance, while causing fewer power interruptions.
Aerial insulated cables are widely applicable in:
Urban areas with densely built environments, narrow streets, and high population density
High-rise residential and commercial districts where safety requirements are stringent
Forested regions where tree contact is unavoidable and pruning is impractical
Rural distribution networks and difficult terrains such as hilly, coastal, and forest areas
Temporary power supply and construction sites
Product Range from Hebei Yongshang Cable Group
Hebei Yongshang Cable Group offers a comprehensive range of Aerial Insulated Cables designed to meet diverse project requirements. Our product portfolio includes:
Model Series: JKV, JKY, JKYJ, JKLV, JKLYJ, JKLY, JKLHV, JKLHY, JKLHYJ, JKTRYJ, JKLYJ/B, JKLHYJ/B, JKLYJ/Q, JKLHYJ/Q, JKLY/Q, JKLHY/Q, JKLGYJ, JKLGY, JKLGYJ/Q, JKLGY/Q
Specifications: 10–400 mm²
Rated Voltage: 1kV, 10kV
Our aerial insulated cables are constructed with high-quality conductors—including aluminum, aluminum alloy, steel core aluminum stranded wire, and soft copper—combined with PVC, PE, HDPE, or XLPE insulation to suit different environmental and performance requirements. The XLPE-insulated version allows a maximum rated operating temperature of 90°C, with a short-circuit temperature of up to 250°C for 5 seconds.
With stable performance and reliable quality, Yongshang’s Aerial Insulated Cables are ideal for power transmission and distribution in urban, rural, and industrial applications worldwide.
For more information or technical support, please contact Hebei Yongshang Cable Group.
