Overhead Line Wires

Overhead lines, sometimes referred to as Aerial conductors, are often specified where there is significant distances to cover and where these cables are best positioned far out of reach. The distances to cover, the environmental conditions it will face, and the location are all factors in specifying the appropriate cable.

Overhead Line Manufacturing Specifications

The main classifications of bare conductor are AAC (All Aluminium Conductor), AAAC (All Aluminium Alloy Conductor) or ACSR (Aluminium Conductor Steel Reinforced). AAC is most commonly found in urban areas with frequent supports and short spans. It is also used in coastal regions where salt in the air can cause corrosion - the All Aluminium wire providing corrosion resistance - and specified for use in the railway industry for OHL electrification. AAAC tend to be specified where greater mechanical resistance is required and where there is a reduced sag characteristic. The ACSR, with its steel reinforcement provides additional strength and where the spans run for larger distances, such as across rivers. 

The advantages of AAC, AAAC and ACSR come in their lightweight properties. These overhead lines have no specified voltage rating - it will depend on the type of installation - although the higher corona limit of ACSR makes it beneficial when used with high voltage and extra-high voltage transmission. The overhead line wires are manufactured in accordance with various national standards and can be sized appropriately - including ASTM B231, TS IEC 1089, DIN 48201, BS 215, and Spanish standard UNE 21.018.

Also within the family of Overhead Lines are Aerial Bundle Cables. These low voltage and medium voltage cables, abbreviated as ABC, are wrapped in insulation, with the medium voltage variants also having an outer sheath. They lay up and twist multiple insulated single cores together - medium voltage ABC also tend to have a steel wire support running through the centre for applications including street lighting and secondary pole to pole service cables. They're also often used in temporary power installations in the construction industry. The insulation provides a protective barrier in the event of sparks or shorts. 

Our ABC Aerial Bundle Cables are available in specifications meeting various national standards including British standard BS7870, French standard NF C33 209, Australasian standard AS/NZS 3560 Part 1, International IEC standard IEC 60502-1, TNB Specification, and HD 626 S1.

For support with specification and suitability for your project, or advice on cable sizing, please talk to our technical team.