Cable trays can be used as ground wires

Metal cable trays can be used as equipment grounding conductors (EGCs) if they meet NEC requirements and are properly bonded and grounded.Conditions for Using Cable Trays as Grounding ConductorsMetallic cable trays may serve as the EGC in electrical installations, but only under specific conditions. The tray must be made of conductive metal such as steel or stainless steel, and it must be electrically continuous and mechanically secure throughout the installation . Non-metallic cable trays cannot be used as grounding conductors . The tray must also meet the minimum cross-sectional metal area requirements specified in NEC Table 318-7(b)(2) to safely carry fault currents .Installation and Bonding PracticesWhen using a cable tray as a ground path, all sections should be bonded together using grounding clamps or jumpers to ensure electrical continuity . If an insulated EGC is installed within or alongside the tray, it should be bonded to each or alternate tray sections to prevent the conductor from being displaced under fault conditions . In corrosive environments, insulated conductors with tin or zinc-plated connectors are recommended to prevent electrolytic corrosion, especially when using aluminum trays .Safety and ComplianceEven if the cable tray is not used as an EGC, all metallic trays must be grounded according to NEC Article 250.96 to prevent electrical shock and equipment damage . Proper grounding ensures that stray currents are safely diverted to earth, reducing the risk of fire, electric shock, and equipment malfunction . Regular inspection of grounding connections is recommended, typically annually or after maintenance or electrical faults .SummaryMetallic trays only: Aluminum, steel, or stainless steel trays can serve as EGCs.Electrical continuity: All tray sections must be bonded and continuous.Cross-sectional requirements: Must meet NEC minimum metal area for fault current capacity.Non-metallic trays: Cannot be used as grounding conductors.Supplemental EGCs: Optional insulated conductors can be added for additional safety.Inspection: Grounding connections should be checked regularly to maintain safety and compliance. By following these guidelines, cable trays can safely function as ground wires while complying with NEC standards and ensuring electrical safety.