| Cooperating organisations |
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6 | (1) |
| Acknowledgements |
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7 | (1) |
| Preface |
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8 | (1) |
| Introduction |
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9 | (2) |
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Chapter 1 The regulations concerning protection against overcurrent |
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11 | (8) |
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11 | (1) |
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1.2 Nature of overcurrent and protection |
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12 | (1) |
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1.3 Statutory requirements |
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13 | (1) |
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1.4 Omission of protection |
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13 | (1) |
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13 | (1) |
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1.6 Duration of overcurrent |
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14 | (1) |
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1.7 Coordination and discrimination |
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14 | (5) |
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Chapter 2 Protection against overload |
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19 | (24) |
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19 | (1) |
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19 | (2) |
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2.3 Selection of protective device |
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21 | (2) |
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2.4 Selection of conductor cross-sectional area with overload protection |
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23 | (1) |
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2.5 Omission of protection against overload |
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24 | (5) |
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29 | (1) |
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2.7 Avoidance of unintentional operation of circuit-breakers |
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30 | (3) |
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2.8 Current ratings of low voltage assemblies (switchboards, panel boards, distribution boards, etc.) |
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33 | (1) |
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2.9 Cables for star-delta starters |
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33 | (2) |
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35 | (2) |
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37 | (3) |
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40 | (1) |
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2.13 Mineral insulated cables and ring final circuits |
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40 | (3) |
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Chapter 3 Protection against fault current |
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43 | (16) |
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3.1 Types of fault to be considered |
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43 | (1) |
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3.2 Nature of damage and installation precautions |
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43 | (3) |
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3.3 Fault impedance and breaking capacity of protective device |
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46 | (2) |
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3.4 Short-circuit rating of low voltage assemblies (switchboards, panel boards, distribution boards, etc.) |
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48 | (1) |
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3.5 Position of fault current protection and assessment of prospective current |
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48 | (4) |
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3.6 Omission of fault current protection |
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52 | (2) |
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3.7 The use of one device for both overload and fault current protection |
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54 | (1) |
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54 | (4) |
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58 | (1) |
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Chapter 4 Determination of fault current |
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59 | (6) |
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4.1 Determination of fault current by enquiry |
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59 | (2) |
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4.2 Measurement of fault current |
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61 | (1) |
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4.3 Calculation of fault current |
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62 | (1) |
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63 | (2) |
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Chapter 5 Equations for the calculation of short-circuit current |
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65 | (10) |
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5.1 General equation for fault current |
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65 | (1) |
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5.2 Single-phase, line to neutral fault |
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66 | (2) |
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5.3 Conductor temperature and resistance |
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68 | (3) |
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5.4 Single-phase circuits |
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71 | (1) |
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5.5 Line-to-line short-circuit |
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72 | (1) |
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5.6 Three-phase short-circuit |
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73 | (2) |
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Chapter 6 Equations for the calculation of earth fault current |
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75 | (12) |
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75 | (1) |
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6.2 TN-S and TN-C-S systems |
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75 | (1) |
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6.3 Cable enclosure used as a protective conductor |
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75 | (9) |
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84 | (3) |
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Chapter 7 Selection of conductor size |
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87 | (6) |
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87 | (1) |
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7.2 Overload and short-circuit protection by a single device |
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87 | (1) |
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87 | (1) |
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88 | (1) |
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7.5 Energy let-through characteristics |
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88 | (3) |
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7.6 Duration of short-circuit current |
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91 | (1) |
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7.7 Status of adiabatic equations |
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91 | (1) |
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7.8 Alternative values of k |
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92 | (1) |
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7.9 Appendix 4 of BS 7671 |
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92 | (1) |
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Appendix A Calculation of reactance |
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93 | (6) |
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93 | (1) |
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A2 Line to neutral, single-phase faults |
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93 | (2) |
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A3 Line-to-line, single-phase, short-circuit |
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95 | (1) |
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A4 Three-phase short-circuit |
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95 | (2) |
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97 | (2) |
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Appendix B Calculation of k for other temperatures |
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99 | (2) |
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99 | (2) |
| Index |
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101 | |
