IEC 60228-2004 pdf – Conductors of insulated cables

IEC 60228-2004 pdf – Conductors of insulated cables.
1 Scope This International Standard specifies the nominal cross-sectional areas, in the range 0,5 mm 2 to 2 500 mm 2 , for conductors in electric power cables and cords of a wide range of types. Requirements for numbers and sizes of wires and resistance values are also included. These conductors include solid and stranded copper, aluminium and aluminium alloy conductors in cables for fixed installations and flexible copper conductors. The standard does not apply to conductors for telecommunication purposes. The applicability of this standard to a particular type of cable is as specified in the standard for the type of cable. Unless indicated to the contrary in a particular clause, this standard relates to the conductors in the finished cable and not to the conductor as made or supplied for inclusion into a cable. Informative annexes are included giving supplementary information covering temperature correction factors for resistance measurement (Annex B) and dimensional limits of circular conductors (Annex C). 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 metal-coated coated with a thin layer of suitable metal, such as tin or tin alloy 2.2 nominal cross-sectional area value that identifies a particular size of conductor but is not subject to direct measurement NOTE Each particular size of conductor in this standard is required to meet a maximum resistance value. 3 Classification The conductors have been divided into four classes, 1 , 2, 5 and 6. Those in classes 1 and 2 are intended for use in cables for fixed installations. Classes 5 and 6 are intended for use in flexible cables and cords but may also be used for fixed installations. ? Class 1 : solid conductors. ? Class 2: stranded conductors. ? Class 5: flexible conductors. ? Class 6: flexible conductors which are more flexible than class 5.
5.1 .2 Resistance The resistance of each conductor at 20 °C, when determined in accordance with Clause 7, shall not exceed the appropriate maximum value given in Table 1 . NOTE For solid aluminium alloy conductors, having the same nominal cross-sectional area as an aluminium conductor the resistance value given in Table 1 should be multiplied by a factor of 1 ,1 62 unless otherwise agreed between the manufacturer and the purchaser. 5.2 Stranded circular non-compacted conductors (class 2) 5.2.1 Construction a) Stranded circular non-compacted conductors (class 2) shall consist of one of the materials specified in Clause 4. b) Stranded aluminium or aluminium alloy conductors shall have a cross-sectional area not less than 1 0 mm 2 . c) The wires in each conductor shall all have the same nominal diameter. d) The number of wires in each conductor shall be not less than the appropriate minimum number given in Table 2. 5.2.2 Resistance The resistance of each conductor at 20 °C, when determined in accordance with Clause 7, shall not exceed the appropriate maximum value given in Table 2. 5.3 Stranded compacted circular conductors and stranded shaped conductors (class 2) 5.3.1 Construction a) Stranded compacted circular conductors and stranded shaped conductors (class 2) shall consist of one of the materials specified in Clause 4. Stranded compacted circular aluminium or aluminium alloy conductors shall have a nominal cross-sectional area not less than 1 0 mm 2 . Stranded shaped copper, aluminium or aluminium alloy conductors shall have a nominal cross-sectional area of not less than 25 mm 2 . b) The ratio of the diameters of two different wires in the same conductor shall not exceed 2. c) The number of wires in each conductor shall be not less than the appropriate minimum number given in Table 2. NOTE This requirement applies to conductors made with wires of circular cross-section before compaction and not to conductors made with pre-shaped wires.