If you want to open the door and cut off the power, you can use the travel switch and contactor coil in series to control it. It is not recommended to use the proximity switch. If the withstand voltage, current and other parameters of the main contactor meet your requirements, it is OK. If considering the complete problem of voltage, a 380V contactor can be added between the travel switch and the main contactor for transition. If the transformer is used, I don't think it is necessary. Install instant fuse in the cabinet. When designing the control cabinet, always try to imagine all the problems that may occur and install more prompts or instructions. Install on-off indicator lights on the important contactors (all similar indicator lights are installed on a circuit board uniformly, and can be installed on the door after using the high brightness diode). When there is a fault, it will be clear. Another suggestion is that if you design this cabinet, you can consider adding an electric bell to open the door without powering off, or if the travel switch is broken and the door is opened, the electric bell and the red indicator light will act at the same time. Plus the usual facilities, there won't be any problems.