Cable trays can be used as grounding conductors

Yes, metallic cable trays can be used as equipment grounding conductors (EGC) if installed and bonded according to NEC standards and best practices. Using Cable Trays as Grounding ConductorsMetallic cable trays can serve as the equipment grounding conductor (EGC) in installations where qualified personnel will service the system, provided they meet certain criteria such as minimum cross-sectional area and UL classification for grounding suitability. All metallic trays must be grounded regardless of whether they are used as the EGC, in compliance with NEC Article 250.

96. Non-metallic cable trays, however, cannot be used as grounding conductors.

Bonding and Continuity

Cable trays must be electrically continuous, even if not mechanically continuous, and sections should be bonded together using bolting, splice plates, clamps, or bonding jumpers to ensure a reliable path for fault currents. Flexible jumpers with appropriately sized lugs are recommended at connection points to maintain continuity and safety. When an EGC cable is installed in or on the tray, it is good practice to bond it to each or alternate tray sections to prevent displacement under fault conditions.

Material Considerations

When using cable trays as grounding conductors, care must be taken with material compatibility. For example, a bare copper EGC should not be placed in an aluminum tray due to the risk of electrolytic corrosion in moist environments. Instead, insulated conductors with exposed bonding points using tin- or zinc-plated connectors are preferred.

Safety and Compliance

Proper grounding of cable trays ensures that stray currents are safely diverted to the earth, reducing the risk of electric shock, equipment damage, and interference with sensitive electronics. Grounding also supports compliance with NEC standards, enhances system reliability, and is critical in industrial, commercial, and critical infrastructure installations.

Summary

Metallic trays can be used as EGCs if properly bonded and compliant with NEC standards. Non-metallic trays cannot serve as grounding conductors. Bonding jumpers and flexible connections are recommended to maintain electrical continuity.

Material compatibility must be considered to prevent corrosion. Grounding cable trays improves safety, system stability, and regulatory compliance. By following these guidelines, cable trays can effectively function as part of a safe and reliable grounding system.