Cable tray clamps must comply with mechanical, electrical, and grounding standards such as NEMA VE 2, NEC Article 392, and DIN EN 61537 to ensure safety, structural integrity, and proper bonding.

Key Standards and Guidelines

NEMA VE 2-2018 provides guidance on the design, selection, and installation of cable tray systems, including clamps, focusing on mechanical strength, material selection, and environmental suitability. While NEMA sets the framework, it does not independently test or certify products, so manufacturers must ensure compliance through their own quality control and testing procedures . NEC Article 392 specifies that metallic cable trays can serve as the Equipment Grounding Conductor (EGC). Clamps are used to bond the tray sections and any EGC conductors, ensuring electrical continuity and mechanical stability. Grounding clamps should be tin- or zinc-plated when connecting to aluminum trays to prevent electrolytic corrosion, and bare copper conductors should generally be avoided in aluminum trays . DIN EN 61537 (European standard) defines cable support systems, including trays, ladders, and mesh trays, and specifies that clamps and fittings must withstand mechanical loads, environmental conditions, and provide secure cable routing. Accessories such as clamps, covers, and barrier strips are standardized to maintain spacing, prevent cable movement, and protect against external influences like moisture, oil, or corrosive substances .

Practical Considerations for Cable Tray Clamps

• Material and Finish: Clamps should match the tray material (steel, stainless steel, or aluminum) and may require galvanization or corrosion-resistant coatings for harsh environments .
• Mechanical Load: Clamps must support the weight of cables and maintain spacing without deformation. Support spacing is determined by the tray type and load requirements.
• Electrical Bonding: Clamps must ensure continuous grounding across tray sections. For multi-conductor cables with individual EGCs, clamps can mechanically anchor the EGC to prevent displacement under fault currents .
• Environmental Suitability: Clamps should resist corrosion, temperature variations, and chemical exposure. Stainless steel or coated steel is preferred in industrial or outdoor installations .

Summary

Cable tray clamps are governed by mechanical, electrical, and environmental standards. Compliance with NEMA VE 2, NEC Article 392, and DIN EN 61537 ensures safe installation, proper grounding, and long-term durability. Selection should consider material compatibility, load capacity, corrosion resistance, and bonding requirements to maintain both structural and electrical integrity of the cable tray system .