There is a large gap between what you learn in college and the practical knowhow demanded in the working environment, running and maintaining electrical equipment and control circuits. Practical Troubleshooting Of Electrical Equipment and Control Circuits focuses on the hands-on knowledge and rules-of-thumb that will help engineers and employers by increasing knowledge and skills, leading to improved equipment productivity and reduced maintenance costs. This book will help engineers and technicians to identify, prevent and fix common electrical equipment and control circuits. The emphasis is on practical issues that go beyond typical electrical principles, providing a tool-kit of skills in solving electrical problems, ranging from control circuits to motors and variable speed drives. The examples in the book are designed to be applicable to any facility. 1.Discover the practical knowhow and rules-of-thumb they don't teach you in the classroom2.Diagnose electrical problems 'right first time'3.Reduce downtime
Author(s): Mark Brown, Jawahar Rawtani, Dinesh Patil
Year: 2004
Language: English
Pages: 247
Contents......Page 6
Preface......Page 8
1.1.1 Basic electrical concepts......Page 9
1.1.2 Transformer......Page 11
1.1.4 Types of transformers......Page 13
1.1.5 Connections of single-phase transformer......Page 14
1.1.6 Three-phase transformers......Page 15
1.1.7 Testing transformers......Page 17
1.2.1 Electromechanical energy conversion......Page 20
1.2.2 Basic principles of electromagnetism......Page 21
1.2.3 The basic principle of motor......Page 22
1.2.5 Idealized machines......Page 23
1.2.6 Basic principles of electrical machines......Page 24
1.2.7 Types of electrical machines......Page 25
1.3.1 Single-phase power system......Page 27
1.3.2 Three-phase power systems......Page 28
1.3.3 Power measurement in a three-phase system......Page 29
1.4 Meters used in troubleshooting......Page 30
2.2.1 Power circuits......Page 32
2.2.2 Control circuit......Page 34
2.3 Reading and understanding electrical drawings......Page 36
2.3.1 Things to look for in an electrical drawing......Page 37
2.4.1 PLC terminology......Page 44
2.4.3 Basic terms used in ladder logic......Page 45
2.4.4 Ladder logic instructions......Page 46
2.5 Wires and terminal numbering......Page 47
3.1 Introduction......Page 50
3.2 Basic principles in using a drawing and meter in troubleshooting circuits......Page 51
3.3 Checks for circuit continuity with disconnected supply......Page 52
3.4 Checks for circuit continuity with live supply......Page 55
3.5 Tests and methods......Page 56
3.6.1 Lamp indicators......Page 57
3.6.2 Voltmeters and ammeters......Page 59
3.6.3 Multimeters and ohmmeters......Page 62
3.6.4 CRO (cathode ray oscilloscope)......Page 64
3.6.6 Insulation-resistance testers or meggers......Page 65
3.6.7 Testing accessories......Page 66
3.7.2 Different wiring diagrams......Page 69
3.8 Accurate wiring of circuits and connections......Page 70
3.8.1 Optional tests......Page 72
3.9 Tests for installation and troubleshooting......Page 74
4.2 Fundamentals of three-phase AC motors......Page 76
4.2.1 Principles and operation of three-phase induction motors......Page 77
4.2.2 Speed–torque characteristics of an induction motor......Page 78
4.2.3 Induction motor startup......Page 79
4.2.4 Induction motor losses and efficiency......Page 80
4.2.5 Principle and operation of a three-phase synchronous motor......Page 81
4.2.6 ‘V’ curves......Page 82
4.2.8 Hunting of synchronous motors......Page 83
4.2.9 Principle and operation of a three-phase wound rotor motor......Page 84
4.2.10 Wound-rotor motor startup......Page 85
4.3.1 Types of single-phase AC motors......Page 86
4.3.2 Types of single-phase induction motors......Page 87
4.4.1 Types of DC motors......Page 89
4.4.2 Characteristics of DC motors......Page 92
4.5 Motor enclosures......Page 93
4.6 Motor terminal identification and connection diagram......Page 94
Terminal connection diagram......Page 95
4.7.2 Motor insulation......Page 96
4.7.3 AC motor connections......Page 97
4.8.1 Induction motor......Page 98
4.9 Motor braking methods......Page 99
4.9.1 Electrical motors braking methods......Page 101
4.9.2 Induction motors braking methods......Page 102
4.9.3 Synchronous motors braking methods......Page 106
4.9.5 Shunt motor......Page 107
4.10.1 Methods of testing DC machines......Page 108
4.12 Motor failures and methods to extend its life......Page 114
4.13 Motor control trouble–remedy table......Page 115
4.14 Motor starter check chart......Page 117
5.2.1 Switches......Page 120
5.2.2 Circuit breakers......Page 121
5.2.5 Oil circuit breakers......Page 122
5.2.7 Vacuum circuit breakers......Page 123
5.2.9 High-voltage circuit breakers......Page 124
5.2.10 Motor circuit breakers......Page 125
5.3.3 Phase failure relays......Page 126
5.4 Switchboards......Page 127
5.5 Motor control center......Page 128
6.2 Basic VSD......Page 129
6.2.1 Converters......Page 130
6.3 Power electronic components......Page 131
6.3.1 Power diodes......Page 132
6.3.2 Power thyristors......Page 133
6.3.3 Gate-controlled power electronic devices......Page 134
6.4 Electrical VSDs......Page 140
6.5.1 Assumptions......Page 143
6.5.2 Three-phase commutation with six-diode bridge......Page 146
6.5.3 Line-commutated diode rectifier bridge......Page 147
6.5.4 The line-commutated thyristor rectifier bridge......Page 150
Practical limitations of line-commutated converters......Page 154
6.5.5 Quadrant thyristor-controlled rectifier......Page 156
6.6 Gate-commutated inverters (DC/ AC converters)......Page 157
6.6.1 Single-phase square wave inverter......Page 158
6.6.2 Single-phase pulse width modulation (PWM) inverter......Page 160
6.6.3 Three-phase inverter......Page 163
6.7.1 Operator information and fault diagnostics......Page 165
6.8.1 General installation guidelines......Page 168
6.9.1 Cable connection requirements......Page 171
6.9.2 Power supply cables......Page 172
6.9.4 Control cables......Page 173
6.10 Precautions for start/stop control of AC drives......Page 174
6.11.2 Hard-wired connections to PLC control systems......Page 177
6.12.1 The purpose of commissioning......Page 178
6.12.3 Correct parameter settings selection......Page 179
7.1.1 Basic control circuit for DOL (direct-on-line) starter......Page 181
7.1.2 Star–delta 3 starter......Page 183
7.1.3 Autotransformer 3 starter......Page 184
7.2.2 Digital output......Page 185
7.3 Two-wire control......Page 186
7.4 Three-wire control – start/stop......Page 187
7.5.1 Start/stop/jogging circuit using push buttons......Page 188
7.6 Sequence start and stop......Page 189
7.8 Reversing circuit......Page 191
7.8.1 Jog type for/rev/off circuit using selector switch......Page 192
7.8.2 Latch type for/rev/stop circuit using pushbuttons......Page 193
7.9.1 Plugging......Page 195
7.9.2 Anti-plugging......Page 196
7.11 Overload protection......Page 197
7.12 Troubleshooting examples......Page 198
7.13 Troubleshooting strategies......Page 200
7.13.1 General document checklist for troubleshooting......Page 201
7.14 Ladder logic design exercise......Page 202
Appendix A: Units and abbreviations......Page 203
Appendix B: Troubleshooting......Page 204
Appendix C: Low-voltage networks......Page 221
Index......Page 240
