INDEX. 



359 



Temperature of transformers, see 



Transformers 

 Temperature rise, computed from 



change in resistance, n 

 Third harmonic, in delta-connections, 



217 



in generator coils, 219 

 in star-connections, 218 

 Thompson, S. P., on regulation of 



alternators, 100 

 on wave analysis, 339 

 Thomson, Sir William, on wave an- 

 alysis, 339 

 Three-phase systems, 197 



delta and star currents and vol- 

 tages, 204 

 measurement of power in, 228 



230, 233 

 power in, 205 



transformation to 2-phase, 243 

 Thury system of direct current power 



transmission, 221 

 Time degrees, 106 

 Tirrell regulator, 13, 70, 251 

 Topographic method, 199, 203 

 Torda-Heymann, on regulation of 



alternators, 100 

 Torque, expressions for, 28 



electrical measurement of, 40 



how created, 28 



in a generator, 27 



in a motor, 30 



in compound motor, 35 



in differential motor, 36 



in induction motor, 274, 280, 285 



in series motor, 39, 40 



in single-phase and polyphase 



machinery, 197 

 in synchronous motor, 307 

 static, 29 



Total characteristics (see Character- 

 istics), 7, 8, 19 

 Tuttle, E. B., on the effect of iron 



in distorting wave form, 182 

 on wave analysis, 339 

 Transformer, adjustment of voltage 



in testing, 172 

 aging of iron in, 130 

 all-day efficiency, 167 

 auto-transformers, 134-136 

 best frequency for, 64 

 circle diagram, 179-195 

 circulating current test, 144 

 computation of efficiency, 166 

 constant current, 127 

 constant current from constant 

 potential, 190 



Transformer, copper loss, 165 



core loss, 155 



current density in, 140 



current ratio of, 143 



design data, 139-142 



electromotive force and flux, 

 144, 146 



efficiency, 139, 178 



equivalent circuits of, 186-192 



equivalent leakage reactance of, 

 150 



equivalent primary quantities, 187 



equivalent resistance of, 150, 159, 

 160 



exciting current, 137, 151, 153, 

 154 



flux density in, 140 



form-factor, effect of, 176 



general discussion of, 179-189 



harmonics due to hysteresis, 182 



heat runs, 177 



heating of, 130 



hysteresis in, see Hysteresis 



insulation tests, 177 



impedance, 163 



impedance ratio, 165 



impedance voltage, 162 



instruments for testing, 171 



load losses in, 161 



loading back method, 177 



losses in, 129 



magnetic densities in, 141 



magnetic leakage in, 137 



magnetizing current in, 154, 180 



maximum efficiency of, 167 



net and gross cross-section, 140 



normal current and voltage in, 1 73 



open circuit test, 151 



operation and study of, 128-149 



phase of primary and secondary 

 electromotive forces and cur- 

 rents, 134 



polarity of coils, 132, 133 



polarity test by alternating cur- 

 rent, 142 



polarity test by direct current, 

 143 



polyphase, 131, 210 



potential ratio of, 143 



ratio of transformation of, 133 



reactance drop in, 129 



reactance of, 163 



regulation of, 139, 167, 193, 194 



resistance drop in, 129 



resistance of, 163 



secondary quantities in terms of 

 primary, 187 



