The original circuit: 380 air switch +2 self reset button switch (green to do start, red do stop) + 380V AC contactor + 380V 15KW motor. Now want to join the way to stop the circuit, with the sensor to do input, through the intermediate relay to achieve the control of the main circuit in the AC contactor, I would like to ask, what is the intermediate relay? How about drawing the whole schematic? thank you!
KA1 is the intermediate relay, the ordinary intermediate relay line, the coil voltage is AC220V, the intermediate relay normally closed in series in the control circuit, when the input signal is closed, KA1 coil power, normally closed off, KM coil power, motor stop
380V by three-phase four-wire, the original AC contactor coil by 220V, the original circuit is the same? Do not know how much voltage the sensor can output, in general, the middle relay can not be directly used for the main line, the contact can not stand.
I do not understand how you want to control, I am here is the sensor must be closed, press the start button QS2, contactor coil KM was electric pull, the motor running, the sensor signal operation (disconnected), the middle relay coil power failure , Contactor coil power to stop working. So loop.
Weak control of strong electricity, is the basic principle of control, you can use the intermediate relay (DC 24V coil) auxiliary contact control AC contactor pull or disconnect, indirect control motor start and stop:
Turn left to turn right
The red circle position in the figure above is the socket of the intermediate relay, the 11 and 10 terminals are the coils of the relay, and the DC24V is pulled after the load.
When the coil is energized, the 8 and 12 terminals are normally open, turn on, load AC, control contactor A1 and A2 (also coil) live, the final control contactor pull.
