Detailed Explanation of Model Specification of Steel Core Aluminium Strand
LGJ is the symbol of steel-cored aluminum stranded wire, where L is the abbreviation of aluminum wire, G is the abbreviation of steel core, and J is the abbreviation of stranded wire.
240/40 is the nominal cross section of the steel-cored aluminum stranded wire: aluminum 240 mm2, steel 40 mm2;The structure of wires is 26 aluminum wires and the diameter of aluminum wires are 3.42 mm, 7 steel wires and the diameter of steel wires are 2.66 mm. The calculated cross section of aluminum is 238.85 mm 2 , the calculated cross section of steel is 38.90 mm 2 , the total calculated cross section is 277.75 mm 2 ; the outer diameter of the wire is 21.66 mm; the DC resistance of the wire is not more than 0.1209 Ω / km; rated tensile force 83370N (Newton); unit mass 964.3kg/km; manufacturing length 2000 meters; the short-circuit current is changed with the location of the access system and the equipment of the access system. It can be calculated after have the complete wiring diagram, and the impedance of the line is also changed according to the way the line is installed,calculated according to the drawings too.
For transmission lines above 10kv, aluminum-clad steel strand (LGJ) is widely used as conductor in China at present, that is, aluminum wire is used to wrap steel wire, steel wire is used to transfer current, aluminum wire is used to reduce corona and other losses, and the cross section of wire is gradually enlarged according to different voltage. For example, the current domestic high-voltage 500kv transmission line wire, the general use of LGJ-400/35 wire.