Al 59-a Swedish standard for overhead aluminium alloy conductors with 59% conductivity (IACS)

For many years distribution and transmission lines have been designed using aluminum conductors steel reinforced (ACSR) or in some countries all aluminium alloy conductors (AAAC). Both types normally have a conductivity calculated on the total area of 53-54% copper (IACS). Since the mid-1970s the cost of producing electric energy has grown rapidly, leading to an increase in the cost of losses. An attempt to find new conductor material producing fewer losses in the network was started in Sweden at the beginning of the 1970s and led in 1979 to the release of a new conductor standard called Al 59, where 59 stands for its conductivity (IACS). The authors deal with the cost of overhead lines and criteria for the choice of conductors. A comparison is made between Al 59 and ACSR