What is the main grounding and what is the auxiliary grounding? What's the difference between main grounding and auxiliary grounding?

1, auxiliary grounding: set the bus bar connecting the electrical equipment shell of underground area, mining area substation, electromechanical room and distribution point with local grounding electrode and cable grounding part.

2. Main grounding: also known as "general grounding terminal", it is used for grounding the whole building, which is one level higher than the grounding trunk line above.

The differences between the two are as follows:

First, the application is different.

1, auxiliary grounding: coal science and technology (first-class discipline), mine electrical engineering (two disciplines), mine electrical safety (third-class discipline).

2. Main grounding: each building only needs one main grounding bus, one end of which is connected to the grounding trunk line and the other end is connected to the protector device, and it is best to use a special shielding sheath.

Second, the characteristics are different.

1. auxiliary grounding: copper busbar is adopted, with the minimum cross-sectional size of 6mm (thickness) × 100mm (width), and the length can be determined according to the actual needs of the project.

2. Main grounding: If there is only one main grounding wire in the whole building, this main grounding bus is unnecessary, and the main grounding bus also plays the role of main grounding bus.

Third, the regulations are different.

1. auxiliary grounding: try to use tin plating to reduce contact resistance.

2. Main grounding: As the connection point between the grounding trunk line and the equipment grounding line in the integrated wiring grounding system, the ideal position of the main grounding bus should be located in the external lead-in room or the building wiring room.

Baidu encyclopedia-auxiliary grounding bus

Baidu Encyclopedia-Main Grounding Bus