Cable Tray Ground-Based Reinforcement Solution

Ground-based reinforcement for cable trays involves using the tray itself as an equipment grounding conductor (EGC) or installing dedicated grounding conductors and bonding hardware to ensure safety, compliance, and structural integrity. Using Cable Tray as an Equipment Grounding Conductor (EGC)Metallic cable trays can serve as the EGC if they meet NEC 2023 Article 392. 60(A) requirements.

This approach eliminates the need for separate grounding wires, reducing material and labor costs. Key considerations include: Tray Identification and Sizing: Straight sections and fittings must be marked with the cross-sectional area of metal, ensuring compliance with NEC Table 392. 60(B) for current-carrying capacity and fault protection.

Bonding Discontinuities: Where trays are mechanically discontinuous, properly sized bonding jumpers must connect sections to maintain a low-impedance path to ground. Connection to Panels: Bond the tray to main distribution panels, motor loads, and power panels using appropriately sized copper or aluminum conductors based on the largest overcurrent protection device. Safety Considerations: Only qualified personnel should service systems where the tray acts as the EGC, and bare copper should not be used in aluminum trays to prevent electrolytic corrosion; insulated conductors with tin or zinc-plated connectors are recommended.

Dedicated Grounding Solutions

For installations requiring separate grounding conductors, products like the nVent CADDY Wire Basket Tray Ground Bolt provide secure connections for each tray section. These bolts allow a ground wire to pass through and bond directly to the tray, ensuring UL compliance and reliable fault current paths.

Structural Reinforcement and Support

Cable trays must also be mechanically reinforced to handle cable weight and environmental conditions: Support Systems: Use brackets, splices, and mounting hardware to secure trays to floors, walls, or ceilings. Wire basket trays offer integrated sidewalls for high-volume cable containment and welded steel mesh for strength. Corrosion Protection: Steel or stainless steel trays can be galvanized or powder-coated to resist corrosion in industrial environments.

Mechanical Bonding: Grounding clamps not only provide electrical continuity but also mechanically anchor EGCs to prevent displacement under fault currents.

Best Practices

Evaluate whether the tray can serve as the EGC or if separate conductors are required based on installation environment and NEC compliance. Ensure all bonding jumpers and grounding connections are sized according to the largest overcurrent device. Use insulated conductors in aluminum trays to prevent corrosion.

Regularly inspect mechanical and electrical connections to maintain system integrity. By combining proper grounding techniques with robust mechanical support, cable tray systems can achieve both electrical safety and structural reliability, meeting industry standards and minimizing installation costs.