The connection methods for the primary grounding of the distribution box are as follows

The primary grounding of a distribution box is achieved by connecting a properly sized copper ground wire from the power source to the PE (protective earth) bar inside the box, ensuring all internal components and the box itself are securely grounded. Steps for Proper Grounding1. Identify the Grounding Point: Open the distribution box and locate the grounding bar or PE bar, which is usually marked with "PE" or a grounding symbol.

This is the main connection point for the grounding wire. 2. Connect the Power Ground Wire: Use a yellow-green insulated copper wire with a cross-sectional area meeting local standards (e.g., 6 mm² internationally or 10 AWG in the US).

Strip the wire end, insert it into the PE bar terminal, and tighten the screw firmly to ensure a reliable connection. 3. Ground Internal Components: Any electrical components inside the distribution box that require grounding should be connected to the PE bar using copper wires.

This ensures safe operation and prevents potential electric shock or equipment damage. 4. Connect the Box to the Central Ground: Attach a ground wire from the distribution box mounting plate to the factory or facility central grounding point.

This ensures the box itself is at the same potential as the main grounding system, reducing the risk of voltage differences. 5. Verify Ground Resistance: The total resistance between all grounded parts should be less than 0.

1 ohm. For longer cable runs or multiple components, parallel grounding wires may be used to maintain low resistance. 6.

Additional Precautions: Ensure all connections are clean, corrosion-free, and mechanically secure. Avoid sequential grounding chains; instead, use parallel connections to prevent a single point of failure. Regular inspection and testing of grounding resistance are recommended to maintain safety and system reliability.

Summary

Proper primary grounding involves: connecting the main ground wire to the PE bar, grounding all internal components, linking the box to the central ground, using correctly sized copper wires, and verifying low resistance. Following these steps ensures personnel safety, equipment protection, and system stability in the distribution network.