. The Street railway journal . works, and no expense has been saved in originalinvestment to secure the most satisfactory results in practicalmanufacturing. The company has reaped rich rewards for itsefforts. An interesting and instructive insight into the kinds of motorsof the three-phase type manufactured is given in this same book,in the form of a lecture delivered by O. Lasche, engineer of thecompany, before the German Engineering Society. He pointsout the difference between starting motors by short circuiting thearmatures and by the introduction and gradual cutting out of re-sistance, the
. The Street railway journal . works, and no expense has been saved in originalinvestment to secure the most satisfactory results in practicalmanufacturing. The company has reaped rich rewards for itsefforts. An interesting and instructive insight into the kinds of motorsof the three-phase type manufactured is given in this same book,in the form of a lecture delivered by O. Lasche, engineer of thecompany, before the German Engineering Society. He pointsout the difference between starting motors by short circuiting thearmatures and by the introduction and gradual cutting out of re-sistance, the use and advantages of motors with collecting rings,etc. The reduction of the phase differences is demonstrated in a verycomprehensive manner to have a great bearing on the cost ofrunning machinery and on the saving of copper conductors. explains that the phase difference between old and newtype induction motors has been decreased by from 15 to 20 percent. This will decrease the idle currents in the conductors, and,. THREE-PHASE MOTOR AND STARTING RHEOSTAT allowing the same total actual and apparent drop, the conductorsneed be but 60 per cent in cross section, as compared with theold type induction motors. Four types of motors are built andused under different circumstances. 1. Motors with armatures short circuited for starting. 2. Motors with collector rings. 3. Motors with regulatable collector rings. 4. Motors with armature resistance. (Fig. 3.) The first named is by far the simplest and is not subjected toany appreciable depreciation; it can run for weeks without atten-tion. The starting torque of these motors is double that of the runningtorque, and this makes them well adapted for lathe or milling motors larger than 5 it is advisable to introduce a startingrheostat, in order to avoid heavy fluctuations, especially when in-candescent lamps are fed from the same mains. It should be re- membered that these starting resistances do not increase the start
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
