TM 55-2210-224-12
1-13.
TRACTION MOTORS AND SWITCHING DEVICES (cont)
1 TRACTION MOTORS (M1, M2, M3, AND M4). The traction motors are direct current series type. The unit is
supported by motor supports on the motor ends and the axle bearings at the gearbox end. Each motor is connected
to its axle through a set of double reduction gears.
2 POWER CONTACTORS (P1, P2, P3, AND P4). Connect the traction motors, in parallel combination, to the main
generators. The power contactors connect and interrupt the dc current. The power contactors carry both low-voltage
current for the interlock circuits and high-voltage current for the traction motors.
3 WHEEL SLIP RELAYS (WSR1 AND WSR2). When a pair of wheels slips, relay WSR1 or WSR2 is energized, turning
on the wheel slip indicator light. WSR1 is connected to the front set of wheels, and WSR2 is connected to the rear set
of wheels.
4 REVERSER. The reverser controls the direction of the traction motors for forward or reverse motion of the locomotive
by changing the direction the current flows through the traction motor fields. The reverser is controlled by the reverser
handle on the control console. Moving the handle in the desired direction energizes one of two reverser coils, which
directs air pressure to pneumatic cylinders. The pneumatic cylinders instantly switch the reverser contacts to the
desired direction mode.
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