Numerical control wire forming machine design, installation, maintenance and transformation of unsafe phenomenon

Today, the analysis of nc wire forming machine design, installation, maintenance and transformation may appear in the unsafe phenomenon: disorderly connection of the middle line to PE.
Just take China's national standard GB/T5226.1 as an example, in which 5.1 clearly stipulates, "Inside electrical equipment, the center line and protection grounding circuit should not be connected.
The PEN terminal should not be used inside the mechanical cabinet."
I have encountered more than one case of wire forming machine tool after transformation. Due to the increase of components, AC220V power supply is needed, so the first phase of three-phase 380V is directly connected to the PE grounding end of the machine tool to form AC220V. After the addition of three-phase electrical components, the lead line is connected to the PE terminal.
Obviously, if somewhere is disconnected due to mechanical failure, then the device becomes an electrified body with 220VAC voltage to the ground.
The equipment at this time can cause direct electric shock injury to personnel.
In general, CNC wire forming machine tool manufacturers according to national standards, "only in the user's consent can use the middle line.
The use of neutral wires shall be clearly indicated in the mechanical technical documents (installation drawings and circuit drawings), and a single insulated terminal marked N shall be provided for the neutral wires.
Belan wire forming machine manufacturer tips: Wire forming machine tool transformation must not figure to save trouble disorderly connection to the middle line to PE, to ensure the safety of production and maintenance personnel.