Fan control ladder diagram

The high-pressure centrifugal fan PLC control ladder diagram design diagram is
the PLC control diagram of the high-pressure centrifugal fan. Among them, TIMOOO is used for the delay when starting the fan,
TIMO01 is used for the anti-arc internal locking delay, and TIM002 is used for the lag turn-on
delay of KM2.
    For the ladder diagram, the instructions are as follows:
    1) When starting the fan, press the start button. If the yellow light is on, it means that the fan valve is not
completely closed. The yellow light will go out after the fan valve is closed.
    2) After the yellow light goes out, press the start button again, the green light comes on, the starting timer works,
the KM1 and KM2 contactors are connected, the fan motor coils are connected in star shape, and the motor starts
.
    3) After 60 seconds, the fan runs to normal speed, the arc internal lock timer starts
timing, and the KM1 and KM2 contactors are disconnected.
    4) After 5 seconds of internal locking, KM3 contactor is turned on, KM2 is turned on after 3 seconds, and the motor
coil is connected in a triangle. The fan switches to normal operation.
    5) If the motor coil overheats during starting or operation, the thermal protection relay will
disconnect the KM2 contactor, the red light will turn on, and the fan will stop running.
    6) If you encounter an emergency or need to stop the fan, press the stop
button. The KM2 contactor is disconnected and the fan stops running.
The motor capacity of the L4 J is large, which causes problems such as long starting time of the fan , excessive current during starting, and poor
operating safety. This system uses PLC for control. By automatically reducing the load, using the star-delta conversion method to reduce the motor starting
current, and performing safety interlock control, we can give full play to the advantages of PLC in reliability and control flexibility to improve the
operational sex.