Welding Methods for Vertical Shaft Cable Tray Supports

Vertical shaft cable trays require careful welding practices to ensure structural integrity, compliance with standards, and safe support for electrical conductors.

Material Considerations

Vertical shaft cable trays are typically made from steel, stainless steel, or aluminum, each requiring specific welding techniques. Steel trays can be welded using MIG or TIG welding, while stainless steel often requires TIG welding to maintain corrosion resistance. Aluminum trays require TIG or MIG welding with appropriate filler rods to prevent cracking and maintain strength.

The choice of material also affects corrosion protection, especially in industrial or outdoor environments.

Structural and Safety Requirements

Compliance with Standards: Cable trays must meet BS EN 61537 or NEC Article 392 requirements for mechanical strength and electrical safety. Load Support: Vertical trays must support the weight of cables without deformation. Welds should be continuous or strategically placed at joints to maintain tray rigidity.

Spacing and Alignment: Rungs or supports should maintain proper spacing (typically 150–230 mm) to prevent cable sag and ensure proper bend radius.

Welding Best Practices

Qualified Personnel: Welding should be performed by certified welders familiar with electrical installation safety and structural welding standards. Joint Preparation: Clean and deburr tray edges before welding to ensure strong, defect-free welds. Weld Type: Fillet welds are commonly used for tray side rails and rungs, while butt welds may be used for connecting tray sections.

Inspection: Post-weld inspection is critical to check for cracks, porosity, or incomplete fusion, which could compromise structural integrity.

Electrical and Grounding Considerations

Continuity: Welds must maintain electrical continuity if the tray serves as an equipment grounding conductor (EGC) per NEC 392. Corrosion Protection: After welding, galvanized or coated trays may require touch-up with compatible coatings to prevent corrosion at weld points.

Installation Tips

Ensure vertical alignment and secure attachment to walls or structural supports. Maintain clearances for maintenance access (minimum 12 inches above trays per NEC 392). Avoid welding in areas where cables are already installed to prevent damage or fire hazards.

By following these guidelines, vertical shaft cable trays can be safely welded and installed, providing reliable support for electrical systems while complying with industry standards and safety codes.