Aluminium conductor steel-reinforced cable (simply ACSR) is a type of high-capacity, high-strength stranded conductor typically used in overhead power lines.It is concentrically stranded conductor with one or more layers of hard drawn 1350-H19 aluminium wire on galvanized steel wire core. The outer strands are high-purity aluminium, chosen for its excellent conductivity, low weight and low cost. The center strand is steel for additional strength to help support the weight of the conductor，and it can be single wire or stranded depending on the size.Steel core wire is available in Class A , B or Class C galvanization for corrosion protection. Additional corrosion protection is available through the application of grease to the core or infusion of the completed conductor with grease.
When ACSR is new, the aluminium has a shiny surface which has a low emissivity for heat radiation and a low absorption of sunlight. As the conductor ages the color becomes dull gray due to the oxidation reaction of the aluminium strands. In high pollution environments, the color may almost turn black after many years of exposure to the elements and chemicals. For aged conductor, the emissivity for heat radiation and the absorption of sunlight increases. Conductor coatings are available that have a high emissivity for high heat radiation and a low absorption of sunlight. These coatings would be applied to new conductor during manufacture. These types of coatings have the ability to potentially increase the current rating of the ACSR conductor. For the same amount of amperage, the temperature of the same conductor will be lower due to the better heat dissipation of the higher emissivity coating.
ACSR conductors are recognized for their major advantages as the following:
a. high Tensile strength
The standard steel core used for ACSR cable is galvanized steel, but zinc-5% aluminium mischmetal alloy coated steel and aluminium clad steel are also available. Higher strength steel may also be used. The use of higher strength steel cores increases the tensile strength of the conductor allowing for higher tensions which results in lower sag.
b. better sag properties
Steel is higher strength than aluminium which allows for increased mechanical tension to be applied on the conductor. Steel also has lower elastic and inelastic deformation (permanent elongation) due to mechanical loading (e.g. wind and ice) as well as a lower coefficient of thermal expansion under current loading. These properties allow ACSR cable to sag significantly less than all-aluminium conductors.
c. economic design
With the features of simple structure,low cost for wire and cable line,large transmission capacity, which is easy to install and maintenance.
d. best suited for transmission lines with long spans
It is conducive to lay with the conditions of cross rivers and valleys and other special geographical conditions.
ACSR cable manufactured by ZMS meets the requirements of all international standards like ASTM,BS,IEC,DIN,NFC,CSA -ETC.