Weld the distribution box frame using firm, uniform seams on properly prepared steel plates, ensuring structural integrity, smooth edges, and compliance with safety standards.

Material Selection

Choose the right metal for the frame based on the environment and durability requirements. Common options include cold-rolled steel for indoor use, stainless steel (304/316) for corrosion resistance, or aluminum for lightweight applications. The steel plate thickness should meet minimum standards: 2.0mm for doors and panels, 3.0mm for the back plate, and at least 1.5mm for the box body ( ).

Welding Method

• MIG or TIG welding is recommended for steel enclosures due to precision and clean seams ( ).
• Ensure uniform, bright, and clean welds free of defects such as welding skin, air holes, or incomplete penetration ( ).
• For thin metals or visible seams, TIG welding provides the best finish.
• Bolt connections should include flat and spring washers, with 2–5 threads exposed for secure fastening ( ).

Frame Assembly

• Ensure all edges and openings are flat and smooth, without burrs or cracks ( ).
• Weld two lugs at the lower left and upper right corners of the back plate using 40x4mm flat steel, 10cm long for stability ( ).
• Maintain proper fit-up and alignment to prevent warping during welding. Large enclosures may require precise tolerances.

Protection and Quality

• Degrease, derust, and phosphatize all steel surfaces before welding or coating to prevent corrosion ( ).
• Ensure the box meets IP3X protection standards and that all insulation is made of self-extinguishing material ( ).
• Check that movable parts, such as doors, open and close smoothly without damaging coatings, and hinges can bear at least 10kg without deformation ( ).

Final Checks

• Inspect welds for uniformity, penetration, and absence of defects.
• Verify that bolt connections are secure and that all components are properly aligned.
• Ensure reserved inlet/outlet holes have sealing accessories to maintain the required protection level ( ). By following these steps, you can weld a distribution box frame that is structurally sound, safe, and compliant with industry standards, ensuring long-term durability and reliable operation.