For lighting distribution boxes, the standard sheet metal thickness is typically 1.5mm to 2.0mm, depending on the box size and structural requirements.

Material and Thickness Guidelines

Lighting distribution boxes are primarily used to control and distribute lighting circuits, which generally carry lower loads compared to power distribution boxes. The thickness of the sheet metal is selected based on the size of the box and the need for structural strength:

• Boxes ≥ 600mm in size: Use 2.0mm thick cold-rolled steel plates to ensure adequate rigidity and durability.
• Boxes < 600mm in size: Use 1.5mm thick cold-rolled steel plates, which is sufficient for smaller lighting loads and lighter fixtures . For outdoor or industrial applications, such as LT distribution boxes, 2mm galvanized iron (GI) sheet steel is commonly used, with reinforcement channels to maintain structural integrity and support mounting hardware .

Size and Structural Considerations

• For boxes with a width between 500mm and 800mm, the steel plate thickness should not be less than 1.2mm.
• For boxes ≥ 800mm, the thickness should be at least 1.5mm to prevent deformation under the weight of internal components .
• When the semi-perimeter of the box body is ≥ 900mm, a minimum thickness of 1.5mm is recommended; for smaller semi-perimeters, 1.2mm is acceptable . These thickness standards ensure that the box can safely house wiring, bus bars, and protective devices without bending or compromising safety.

Additional Considerations

• Protection rating: Boxes should meet IP-55 or equivalent standards for dust and water protection, especially for outdoor installations .
• Reinforcement: Reinforced channels and proper door design improve durability and prevent deformation.
• Material choice: Cold-rolled steel or GI sheets are preferred for corrosion resistance and mechanical strength. By following these thickness standards, lighting distribution boxes maintain structural integrity, safety, and compliance with electrical regulations while accommodating the required wiring and fixtures.