Ground wire routed through cable tray

A ground wire can be routed through a cable tray, either as a separate equipment grounding conductor (EGC) or by using the metallic tray itself as the grounding path, provided proper bonding and installation practices are followed. Using Cable Tray as Grounding ConductorMetallic cable trays can serve as the equipment grounding conductor (EGC) if they meet the requirements of NEC Article 392 and have sufficient metal cross-sectional area to safely carry fault currents. All metallic trays must be grounded regardless of whether they are used as the EGC.

For high-current circuits, steel trays should not be used as the EGC for circuits with ground-fault protection above 600 A, and aluminum trays above 2000 A. Installing a Separate Ground WireA separate grounding conductor can be installed in or on the cable tray. Best practices include: Bonding the EGC to each or alternate tray sections using grounding clamps to ensure electrical continuity and mechanical stability under fault conditions.

Using insulated conductors in aluminum trays to prevent electrolytic corrosion, with insulation removed at bonding points using tin or zinc-plated connectors. Running a continuous grounding wire along the tray length to provide a low-impedance path for fault currents.

Material Considerations

Copper wire is preferred for excellent conductivity and corrosion resistance. Hot-dip galvanized steel or stainless steel may be used in harsh environments for mechanical strength and corrosion resistance. Avoid bare copper in aluminum trays in moist environments to prevent corrosion.

NEC Compliance and Safety

Ensure the grounding system meets NEC Section 250 requirements, including low impedance, permanent electrical continuity, and capacity to safely conduct fault currents. Grounding connections should be mechanically secure and electrically continuous to facilitate proper operation of overcurrent protection devices. Maintain proper separation from flammable materials and avoid exposure to moisture or corrosive environments.

Summary

Routing a ground wire through a cable tray is acceptable and commonly practiced. You can either use the tray itself as the EGC or install a separate grounding conductor. Key considerations include proper bonding between tray sections, corrosion prevention, material selection, and compliance with NEC grounding requirements to ensure safety and reliable fault current management.