One of the forward and reverse circuits of DC motor armature connected with resistor in series to start reverse braking

The circuit is shown in Figure 3-201. The circuit has a two-level starting resistor, and the time relay controls the removal of the starting resistor; the master switch SA controls the forward and reverse operation of the motor; when stopping, reverse connection braking is used, and the reverse connection braking is performed according to the speed
of the motor.
Automatically controlled. This circuit is suitable for series-wound, shunt-wound and compound-wound DC motors .
    In the figure, Rz and Ra are the starting resistors; Ri is the reverse current limiting resistor, which is connected to the armature circuit during the reverse braking process to
limit the reverse braking current. When the motor speed starts from zero in reverse, Ri is short-circuited, which does not affect the normal reverse start.
R4 is the discharge resistor ; KMi is the forward contactor; KM2 is the reverse contactor; KM3 is the main circuit (armature ) contactor;
KM4 is a reverse brake connector. Overcurrent relay KI provides overload and short-circuit protection.