520 



INDEX 



Photometry, 413, 435 



Pin-type insulators, 401 



Pitch factor, 122 



Polarity of synchronous converter, 



370 



methods of reversing, 371 

 Poles for transmission systems, 403 

 Polygon, of currents, 48 



of voltages, 43 

 Polyphase, converters, 344 

 systems, 76 



comparative ratings of 



machines for, 76 

 generation of power for, 79 

 three-phase, 79 

 two-phase, 93 

 uses, 76 

 wattmeter, 59 

 Portable photometers, 438 

 Potential transformer, 221 

 Power,, alternating-current, 22 



effect of phase relations on, 



23 



commerical frequencies for, 8 

 -factor, 24 



correction of, with synchron- 

 ous condenser, 322 

 with synchronous motor, 



324 



definition of, 24 

 diagram for two-wattmeter 



method, 92 

 indicators, 69 



three-phase, 71 

 induction motor, 244 

 in three-phase systems, 83 

 in delta systems, 85 

 in Y systems, 82 

 measurement, 55 



in three-phase systems, 87 

 three wattmeter method, 



87 



two wattmeter method, 89 

 Y-box, 88 



in two-phase systems, 98 

 Primary leakage flux of transformer, 

 178 



Q 



Quadrature component of current, 



49, 323 

 Quarter-phase system, 93 



R 



Range of alternator winding, 104 

 Rating of alternators, 127 

 Reactance, condensive, 30 



due to leakage flux of trans- 

 former, 178 

 equivalent in a transformer, 



184 



inductive, 28 



of alternator armature, 129 

 single-phase transmission line, 



380 



synchronous, 147 

 table of values for transmission 



line, 465 

 three-phase transmission line, 



382 

 Reaction, armature, of alternator, 



132 

 of synchronous, converter, 356 



motor, 311 

 Rectifiers, 333 



commutating, 334 

 electrolytic, 341 

 mercury-arc, 336 

 Tungar, 338 

 vibrating, 334 



Reflection, coefficient of, 419 

 Reflectors, 442 

 Refractors, 442 



Regulation of alternator, 128, 141 

 A. I. E. E. method of determin- 

 ing, 159 



delta-connected, 153 

 electromotive force method of 



determining, 142 

 vector diagram of, 146 

 magnetomotive force method of 



determining, 155 

 vector diagram of, 155, 157 



