. Electric railway journal . except thatall brush holders are handled by a specialist. Thebrush-holder man also smooths the commutators withfine sandpaper, fits the brushes, examines the work of third, fourth and fifth points have correspondinglylower resistance so that a motor can be speeded up, butwhen the fifth point is reached enough resistance isleft to hold the motor to a safe speed. Two meters for the volt-ammeter test are placedcompactly in a box for service in connection with thesame controller and resistance which are used for therunning test. Leads are attached from the controllerto
. Electric railway journal . except thatall brush holders are handled by a specialist. Thebrush-holder man also smooths the commutators withfine sandpaper, fits the brushes, examines the work of third, fourth and fifth points have correspondinglylower resistance so that a motor can be speeded up, butwhen the fifth point is reached enough resistance isleft to hold the motor to a safe speed. Two meters for the volt-ammeter test are placedcompactly in a box for service in connection with thesame controller and resistance which are used for therunning test. Leads are attached from the controllerto the box, and from the box to the fields of the motorunder test. As the controller is moved to the first orsecond points, the current which is passing through thefield is shown on the ammeter. A special table is usedto show what the drop in voltage should be acrossthe fields of each type of motor at different figures were secured by testing a number of fieldswhich were known to be good. With the combined aid. Third Avenue Motor Shop—View of the Shop as Seen fro m Operating Switchboard, Showing Work Benches, Jibs, Armature Trucks, Etc. the men ahead of him, subjects the motors to the light-running tests and gives them final toucheswith the paint. TESTING EQUIPMENTS The testing equipment of the motor room providesfor an test, running test, volt-ammeter test andlight ground test. A transformer with 330-volt pri-mary supply from the substation and 1000-volt and2000-volt secondaries is used for the final trial of allmotors. We use 1000 volts ordinarily, but 2000 voltswhen the work is new and special. The running test comprises a K-ll controller and aset of resistances which are made up of heater coils andcar grids. These resistances are so connected that thefirst point reduces the voltage enough to run a 110-volt storage battery traction motor at a speed of 600 or700 At the second point all the heater coils arecut out, whereby the resistance is
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