Welding Quality Requirements for Cable Tray Supports

Welded cable tray supports must be strong, durable, and compliant with approved welding procedures to safely carry static and dynamic loads.

Key Welding Requirements

Material Selection: Cable tray supports are typically made from steel, stainless steel, or aluminum. Each material requires specific welding techniques to ensure strength and durability. Steel often uses Shielded Metal Arc Welding (SMAW), while aluminum may require Gas Tungsten Arc Welding (TIG) due to its high thermal conductivity and sensitivity to heat.

Welding Procedure Specification (WPS): All welding must follow an approved WPS, which defines the welding process, filler material, preheat requirements, and joint design. This ensures consistency and structural integrity across all supports.

Load-

Bearing Considerations: Welds must withstand both static loads from the weight of cables and dynamic stresses, including vibrations or short-circuit forces. Supports should be installed plumb, level, and rigidly secured to the structure, with welds positioned to avoid stress concentration at tray ends or expansion points. Support Placement: Cable tray supports should be spaced according to standards such as NEMA VE2 or IEC 61537, typically within 600 mm (2 ft) of expansion splice plates and at quarter points of horizontal spans.

Proper placement reduces bending stress on welded joints. Environmental and Safety Considerations: Welding must account for environmental factors like temperature, humidity, and wind. Welders must use calibrated equipment, correct electrodes, and follow safety protocols to prevent accidents and ensure quality.

Post-

Weld Inspection: Non-destructive testing (NDT), such as ultrasonic or radiographic inspection, is recommended to verify weld integrity. Touch-up painting may be required to prevent corrosion and maintain long-term durability. Compliance with StandardsIEC 61537: Ensures mechanical strength, corrosion resistance, and proper installation of cable tray systems and supports.

BS E

N 61537 / BS 6946: Provides guidance for cable tray and channel support systems in the UK, emphasizing safe installation and load accommodation.

NEM

A VE2: Specifies support spacing, expansion splice placement, and hold-down clip requirements for welded supports.

Best Practices

Use competent, trained welders familiar with the materials and standards. Follow approved welding procedures and maintain proper equipment calibration. Ensure supports are rigid, plumb, and correctly spaced to minimize stress on welds.

Conduct post-weld inspections and apply protective coatings to prevent corrosion. Document all welding and inspection activities for compliance and quality assurance. By adhering to these requirements, welded cable tray supports will provide reliable, long-lasting performance, ensuring safety and structural integrity in electrical installations.