Automatic control circuit that only allows the motor to run in one direction (Part 2)

The circuit is shown in Figure 3-92. It uses dual-sense phase sequence protection relay. When the power supply has positive phase sequence (U, V, w), relay
KA is closed. If the power phase sequence is incorrect, KA is released, contactor KM cannot be closed, and the motor cannot work. At the same
time, the light-emitting diode VL lights up and gives an alarm.
    In the figure, the transformation ratios of transformers Ti and Tz are 100:1 and 100:3 respectively. The primary rated voltage is 380V and the capacity is
several volt-amperes.