How to ground the low voltage distribution box?

The low-voltage distribution box, as a device for regulating the circuit system, needs to be so. How should the low-voltage distribution box be grounded? Now let's explain the grounding mode of low-voltage distribution box?

The first letter T of TT grounding power supply system indicates that the neutral point of the power system is directly grounded, and the second t indicates that the metal conductive part exposed by the load equipment is not connected with the live body, but directly connected with the ground, regardless of the system grounding mode. All grounding loads in TT system are called protective grounding.

TN-S is a power supply system that strictly separates the working zero line n from the special protection line PE. It is called TN-S power supply system. When the TN-S power supply system operates normally, there is no current on the special protection line, and there is no voltage on the PE line to the ground. The zero protection of the metal shell of the electrical equipment is connected with the PE special protection line, which is safe and reliable. The manufacturer of the low-voltage distribution box says that it is applicable to the low-voltage power supply systems such as industrial and civil buildings.

TN-C-S refers to the temporary power supply for building construction. If the front part is powered by TN-C mode, and the construction specification stipulates that the construction site must adopt TN-S mode power supply system, the PE line can be separated by the construction low-voltage distribution box at the back of the dotted line. This system is called TN-C-S power supply system.

TN power supply system and TN-C power supply system are protection systems that connect the metal shell of electrical equipment with the working zero line. The manufacturer of low-voltage distribution box indicates that this is called the zero connection protection system. TN-C power supply system uses the working zero line as the zero connection protection line, which can be called the protective neutral line.

The above are the common methods of centralized distribution grounding. What are the grounding methods of low-voltage distribution cabinets? I believe that after reading these, I will have a certain understanding of this and choose the appropriate connection mode according to the actual situation.