Page 620 - Handbook of Electrical Engineering

INDEX 613

Gate turn-off thyristors 405 Hazardous area classification 249
Generator decrement curves, for fault currents Hazardous area types, zones 0, 1 and 2 251
315 Hazardous area zones and divisions 253
Generalised theory of electrical machines Heat rate 35
479, 496 Heat radiator 138
Generators Heat exchanger 80
Excitation 318 High conductivity copper 68
Local captive 354 High impedance earth point 358
Salient pole 291 High power transistors 407
Generators, sizing 13 High-set setting 348
Grids and rods for earthing 352, 369 High voltage generator 78, 471
Ground potential rise 369 High voltage motor 78
Ground or soil thermal conductivity and Hysteresis 140
resistivity 205
I-squared-t characteristic
Hand-held equipment 235 For negative phase sequence current 339
Hand-to-foot resistance 352
Of a contractor 339
Hand-to-hand resistance 352
Of a neutral earthing resistors 323
Hard and soft limits in control valves 56
Of a person 351
Harmonics
Of cables 323
Cancellation 418 Of copper cables 165
Currents 386 Of downstream equipment 176
Design of filters 431 Of fuses 164, 176
Distortion 401, 431 Of molded case circuit breakers 164
Distortion in uninterruptible power supplies Of power equipment 337, 363
449
Of transformers 329
High frequency 136, 406
I-squared-t duty of equipment, prospectively
Injected into a system 429
high 363
Notches due to commutation 399
Impedance
Q-factor of filters 433
Armouring 366
Sharply tuned filers 433
Earth loop, see earth loop impedance 200
Spikes 387
Earthing 355
Voltdrops 386
External, effect of short circuit currents
Harmonic current in switchgear neutral busbars
152
146
Harmonisation of international standards 265 In relation to armouring 186
Hazardous areas 61, 78, 123, 125, 386, 460, Induction motor sub-transient 294
472 Induction motor transient 294
Classification, earthing influenced by 358, Leakage, of a transformer 145
363 Operational 486, 491, 493
Equipment 451 Operational in the D-axis 489
Ex ‘d’ 78 Operational in the Q-axis 489
Ex ‘de’ 78 Per-unit of a transformer 133
Ex ‘n’ 78 Shield transfer in screening 380
Ex ‘p’ 78 Source 366, 492
Gases and vapours 251, 363 Sub-transient 64
Radar 466 Transient 64
Use of four-pole circuit breakers and isolator Increased safety, type of protection 256
365 Indication and control for switchgear 158
Zone 1 and zone 2 78 Induced emf 79
Zone 1 lighting fittings 460 Inductive reactance 99