1、60287-1-1IEC:1994+A1:1995-3-+A2:2001CONTENTSFOREWORD.7INTRODUCTION111 General.131.1 Scope.131.2 Normative references1.3 Symbols.151.4 Permissible current rating of cables.1.4.1 Buried cables where drying out of the soil does not occuror cables in air.211.4.2 Buried cables where partial drying-out of
2、 the soil occurs.231.4.3 Buried cables where drying-out of the soil is to be avoided.251.4.4 Cables directly exposed to solar radiation.72 Calculation of losses.72.1 AC reslstance of conductor.72.1.1 DC resistance of conductor.92.1.2 Skin effect factor y.292.1.3 Proximity effect factor yp for two-co
3、re cables and for twosingle-core cables.292.1.4 Proximity effect factor yp for three-core cables and for threesingle-core cables.312.1.5 Skin and proximity effects in pipe-type cables.2.2 Dielectric losses(applicable to a.c.cables only).32.3 Loss factor for sheath and screen(applicable to power freq
4、uencya.c.cables only).332.3.1 Two single-core cables.and three single-core cables(in trefoilformation),sheaths bonded at both ends of an electrical section.352.3.2 Three single-core cables in flat formation,with regular transposition,sheaths bonded at both ends of an electrical section.372.3.3 Three
5、 single-core cables in flat formation,without transposition,sheaths bonded at both ends of an electrical section.372.3.4 Variation of spacing of single-core cables between sheath bonding.39points.2.3.5 Effect of large segmental type conductors.12.3.6 Single-core cables,with sheaths bonded at a singl
6、e pointor cross-bonded.2.3.7 Two-core unarmoured cables with common sheath.452.3.8 Three-core unarmoured cables with common sheath.472.3.9 Two-core and three-core cables with steel tape armour.472.3.10 Cables with each core in a separate lead sheath(SL type)and armoured.492.3.11 Losses in screen and sheaths of pipe-type cables.49Copyright por International Electrotechnical CommissionTue Sep 09 16:13:24 2003
