. The Street railway journal . tically short-circuited. Theshort-circuiter is likewise actuated by pressed air. To increasethe cooling surface of the rheostats they are provided withcooling pipes. The liquid in the rheostat is raised Ijy adjustingtlie air-ci)ck (jf the controller. The flctails of starting the motors are as follows: First,place the switch-lever of the controller-device at low speedand open the air-cock, and with small throttle valve enable theair to enter. This does two things, it (i) closes the primaryswitch of the 3000-volt circuit and (2) allows the water levelin the rheosta
. The Street railway journal . tically short-circuited. Theshort-circuiter is likewise actuated by pressed air. To increasethe cooling surface of the rheostats they are provided withcooling pipes. The liquid in the rheostat is raised Ijy adjustingtlie air-ci)ck (jf the controller. The flctails of starting the motors are as follows: First,place the switch-lever of the controller-device at low speedand open the air-cock, and with small throttle valve enable theair to enter. This does two things, it (i) closes the primaryswitch of the 3000-volt circuit and (2) allows the water levelin the rheostat to rise slowlv or more rapidl_\, according to theposition iif the throttle valve until the rotor is car will then run at half-speed. If high speed is desiredit is necessary first to shut the air-cock, which disconnects theprimary current. The controller lever is then adjusted at highspeed, thus disconnecting the low-tension motor. The motor-man tlien moves his air-cock and throttle valve, again closing SI. FIG. 28.—SWITCH FOR ST/VRTING synchronism. The rheostat is of the liquid type, with the elec-trolyte forced in and out by compressed air. It consists of acast-iron box with cooling flanges, into which are hung threegroups of sheet-iron plates with indented lower edges. The FIG. 29,—STARTING RHEOSTAT his main switch and admitting the electrolyte until the carreaches full speed. The method of regulating the speed, aswill be seen, is in many particulars similar to the series parallel-connection of continuous-current motors. When starting the
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
