Three-phase four-wire is a collective term for three phase wires and a neutral wire. The phase wire provides power to the motor. Any combination of phase wire and neutral wire provides 220V power to provide power to the control circuit.
So if the AC contactor wants to achieve interlocking, the AC contactor must have a normally closed contact. Specifically, the wiring process is roughly divided into the control circuit and the main circuit, of which the main is the control circuit!
Select a phase wire as the power source of the control circuit and connect it to the start button. The button is connected with the normally open contact of the contactor in parallel to realize the motor self-locking. Then, another normally closed contact of another contactor is connected to another Stop the button, the other part of the button is connected to the zero line, and another group of contactors can be interlocked to achieve interlocking! The main circuit is that the three-phase wire enters and exits from both ends of the contactor to complete the control of the entire circuit.