Page 9 - Handbook of Electrical Engineering

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9 Cables, Wires and Cable Installation Practices 183
9.1 Electrically Conducting Materials used in the Construction of Cables 183
9.1.1 Copper and aluminium 184
9.1.2 Tin 184
9.1.3 Phosphor bronze 185
9.1.4 Galvanised steel 185
9.1.5 Lead 186
9.2 Electrically Non-Conducting Materials used in the Construction of
Cables 187
9.2.1 Definition of basic terminology 187
9.3 Composition of Power and Control Cables 191
9.3.1 Compositional notation 192
9.3.2 Conductor 192
9.3.3 Conductor semiconducting screen 196
9.3.4 Insulation 196
9.3.5 Insulation semiconductor screen 197
9.3.6 Inner sheath 197
9.3.7 Lead sheathing 197
9.3.8 Armouring 198
9.3.9 Outer sheath 198
9.4 Current Ratings of Power Cables 198
9.4.1 Continuous load current 198
9.4.2 Continuous rated current of a cable 199
9.4.3 Volt-drop within a cable 209
9.4.4 Protection against overloading current 242
9.5 Cables with Enhanced Performance 244
9.5.1 Fire retardance 244
9.5.2 Fire resistance 245
9.5.3 Emission of toxic gases and smoke 245
9.5.4 Application of fire retardant and fire resistant cables 246
Reference 247

10 Hazardous Area Classification and the Selection of Equipment 249
10.1 Historical Developments 249
10.2 Present Situation 249
10.3 Elements of Hazardous Area Classification 251
10.3.1 Mixtures of gases, vapours and air 251
10.4 Hazardous Area Zones 253
10.4.1 Non-hazardous area 253
10.4.2 Zone 2 hazardous area 253
10.4.3 Zone 1 hazardous area 253
10.4.4 Zone 0 hazardous area 254
10.4.5 Adjacent hazardous zones 254