Manual electrico

Electrical installation handbook Volume 2
2 edition
nd

Electrical devices

1SDC010001D0202

ABB SACE

Electrical installation handbook

Volume 2

Electrical devices

2nd edition February 2004

First edition 2003 Second edition 2004

Published by ABB SACE via Baioni, 35 - 24123 Bergamo (Italy) All rights reserved

Index

Introduction.............................................................................................. 2 1 Standards 1.1 General aspects .............................................................................. 3 1.2 IEC Standards for electrical installation .......................................... 15 2 Protection of feeders 2.1 Introduction ................................................................................... 22 2.2Installation and dimensioning of cables ......................................... 25 2.2.1 Current carrying capacity and methods of installation .......... 25 Installation not buried in the ground ..................................... 31 Installation in ground ............................................................ 44 2.2.2 Voltage drop........................................................................ 56 2.2.3 Joule-effect losses ............................................................... 66 2.3 Protection against overload ........................................................... 67 2.4 Protection against short-circuit ...................................................... 70 2.5 Neutral and protective conductors ................................................ 78 2.6Busbar trunking systems ............................................................... 86 3 Protection of electrical equipment 3.1 Protection and switching of lighting circuits ................................. 101 3.2 Protection and switching of generators ....................................... 110 3.3 Protection and switching of motors ............................................. 115 3.4Protection and switching of transformers .................................... 131 4 Power factor correction 4.1 General aspects .......................................................................... 146 4.2 Power factor correction method .................................................. 152 4.3 Circuit-breakers for the protection and swiching of capacitor banks........................................................ 159 5 Protection of human beings 5.1 General aspects: effects of current on human beings .................. 162 5.2 Distribution systems .................................................................... 165 5.3 Protection against both direct and indirect contact ...................... 168 5.4 TT system................................................................................... 171 5.5 TN system .................................................................................. 174 5.6 IT system .................................................................................... 177 5.7 Residual current devices ............................................................. 179 5.8 Maximum protected length for the protection of human beings ... 182 Annex A:Calculation tools A.1 Slide rules ............................................................................. 200 A.2 DOCWin ............................................................................... 205 Annex B: Calculation of load current Ib .............................................. 209 Annex C: Calculation of short-circuit current ................................... 213 Annex D:Calculation of the coefficient k for the cables .................. 227 Annex E: Main physical quantities and electrotechnical formulas ................................................... 230

ABB SACE - Electrical devices

1

Introduction
Scope and objectives The scope of this electrical installation handbook is to provide the designer and user of electrical plants with a quick reference,...