Method for fixing the secondary distribution box

A secondary distribution box should be securely mounted using appropriate brackets or bolts, installed at a convenient height, and properly grounded to ensure safety and reliable operation.

Site Selection and Preparation

The secondary distribution box should be installed in a dry, well-ventilated area close to the power supply to minimize power loss and prevent overheating or corrosion. Avoid humid or corrosive environments, and ensure the location allows easy access for inspection and maintenance .

Mounting and Fixing

• Height: The bottom edge of the box is typically installed 1.5 to 1.8 meters above the ground for convenient operation .
• Fixing Method: Use suitable mounting brackets, split bolts, or expansion bolts to secure the box firmly to the wall or structure. For smaller boxes, embedding wood bricks at the installation points and using wood screws is acceptable .
• Alignment: Ensure the box is level and vertical, with a vertical deviation of no more than 3mm. For concealed installations, fill gaps with concrete and coat contact surfaces with anti-corrosion paint .

Wiring Connections

• Incoming and Outgoing Lines: Connect the incoming line from the primary distribution box to the busbar or terminal block inside the secondary box. Ensure firm contact to prevent overheating or electrical faults .
• Wire Types: Use high-temperature resistant copper wires with cross-sectional areas suitable for the load. Follow standard color coding: three-phase lines (A, B, C), neutral (N), and protective earth (PE), .
• Safety Measures: Turn off power during wiring, avoid exposed copper, and ensure all cable inlets and cover joints are sealed properly .

Grounding and Safety

• Grounding: The metal casing, electrical installation board, and all metallic components must be reliably grounded. Connect the protective neutral wire through the terminal board .
• Protection Devices: Install a leakage protector or circuit breaker to provide additional safety. Clearly label AC, DC, or different voltage levels inside the box .

Special Considerations

• In flammable or explosive environments, use explosion-proof distribution boxes and follow specific material and installation standards .
• Ensure that all connections are secure and that the box is mechanically stable to withstand vibration or accidental impact . By following these steps, the secondary distribution box will be securely fixed, electrically safe, and compliant with standard installation practices, ensuring reliable operation and ease of maintenance.