. The Street railway journal . ram-way service. Two of these generators, of300-kw capacity each, have been installed,and these are driven by two Pallitt &Wigsell engines, one unit being clearlyshown in an illustration, Fig. 6. The en-gines are horizontal cross-compound con-densing, of 570 ihp, with cylinders 17 34 ins. diameter, 3 ft stroke, 100r. p. m., with Corliss valves, and patenttrip gear to the high-pressure cylin-der, and slide-valve and cut-off valve to the low-pressurecylinder, and patent single-acting air pump. Eachengine has separate condensing plant, one having a jet conde
. The Street railway journal . ram-way service. Two of these generators, of300-kw capacity each, have been installed,and these are driven by two Pallitt &Wigsell engines, one unit being clearlyshown in an illustration, Fig. 6. The en-gines are horizontal cross-compound con-densing, of 570 ihp, with cylinders 17 34 ins. diameter, 3 ft stroke, 100r. p. m., with Corliss valves, and patenttrip gear to the high-pressure cylin-der, and slide-valve and cut-off valve to the low-pressurecylinder, and patent single-acting air pump. Eachengine has separate condensing plant, one having a jet condenser and the other a surface condenser. 296 STREET RAILWAY JOURNAL. [Vol. XX. No. 10. These two three-phase generators are used for supply-ing current to sub-stations, described later, at a pressureof 5000-5500 volts, this being transformed down to 320 new high-tension, three-phase work has been supplied byMessrs. Ferranti, Ltd., and is shown in Fig. 7; the remain-ing boards, as shown in Fig. 8, for the direct-current sup-. FIG. 6.—55CO-VOLT THREE-PHASE GENERATORS AND ENGINES, HALIFAX volts, and then being transformed by rotary converters tocontinuous current at 500-550 volts for tramway purposesand the supply of current in bulk. 1 he two generators are of the Elec-tric Construction Companys standardslow-speed type, each giving 350 kwat 6000 volts as three-phase current of25 periods, at j00 r. p. m. One ma-chine was built entirely new, while theother was converted from a single-phase alternator working at 80 periodsinto a three-phase machine at 25periods. The armature coils are for-mer wound, thoroughly insulated be-fore fixing in the core slots. The wind-ings were tested with 12,000 volts,between the separate phases and toframe. The steel magnet poles arebolted to a steel shaft, which is furtherbolted to the rim of the cast-iron fly-wheel, which, together with the mag-net, weighs 26 tons. The efficiency ofthe alternator is 95 per cent, while theexciting energy is only 1? per
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
