. The Street railway journal . peed of the motor must be 236 r. p. m. The chief data ofthe two motors are then, as shown in Table I: TABLE I. Single-phase Tliree-phase motor. motor. Rated capacity in horse-power 500 iioo Weight, pounds, G 19,500 22,000 Revolutions per minute, n 236 220 Weight factor / G x 11 X ( 1 4^ 20 v. 2200 X 100 -x IIP / From this table it appears that the weight factor of thesingle-phase motor is more than double that of the corre-sponding three-phase motor; that is to say, the three-phasemotor will develop more than double the power of thesingle-phase motor at the same
. The Street railway journal . peed of the motor must be 236 r. p. m. The chief data ofthe two motors are then, as shown in Table I: TABLE I. Single-phase Tliree-phase motor. motor. Rated capacity in horse-power 500 iioo Weight, pounds, G 19,500 22,000 Revolutions per minute, n 236 220 Weight factor / G x 11 X ( 1 4^ 20 v. 2200 X 100 -x IIP / From this table it appears that the weight factor of thesingle-phase motor is more than double that of the corre-sponding three-phase motor; that is to say, the three-phasemotor will develop more than double the power of thesingle-phase motor at the same weight and number of revo-lutions. A^ery interesting results are also reached if we considerthe whole locomotive. The diagram below was made forthis purpose. To confine the comparison to constructionactually carried out the type of locomotive represented by theItalian model previously mentioned has been adopted. Themechanical part of the locomotive would be changed onlyin so far as the wheel diameter would have to be increased. PLAN AND ELEVATION OF THREE-PHASE LOCOMOTIVE FOR ITALIAN STATE RAILWAYS The latter are now built with three ranges of speed, asreaders of this paper know.* The 8-pole motor of a loco-motive of this type, built by the Ganz Electric Co. for theItalian State Railways, has a capacity, on one hour rating,of 1500 hp, at a weight of tons (metric), and at 220r. p. m. While building new locomotives of the same type themanufacturers have recently found it possible, through somechanges in the design, to increase the rating of the motorsby 20 per cent to 1800 hp, while the external dimensionsand the speed of the motor remain unaltered. Another8-pole motor of similar construction, designed by the GanzElectric Co., developing iioo hp on the one hour ratingat 3000 volts, 15 cycles and 220 r. p. m., weighs 10 metrictons. Neither of these motors has forced draft. This last motor seems suitable for a comparison with thesingle-phase motor of the Pennsylvania locomotiv
Size: 2376px × 1052px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
