How to install the grounding wire in the cable tray

Install a grounding wire in a cable tray by running a continuous conductor along the tray, securely bonding it to each tray section, and ensuring compliance with NEC standards for safety and conductivity.

Planning and Preparation

Before installation, plan the grounding system layout. Identify grounding points, conductor paths, and connection locations. Ensure the design complies with local regulations and NEC Article 392, which governs cable tray systems, grounding, and bonding requirements.

Determine whether the cable tray itself will serve as a grounding path or if a separate equipment grounding conductor (EGC) will be used. Grounding MethodsFull-Length Grounding Conductor: Run a continuous wire along the entire length of the tray. This provides a reliable path for fault currents and reduces resistance.

Using the Cable Tray as Ground: For metallic trays that meet conductivity and strength requirements, the tray can act as the grounding conductor. Use flexible jumpers with lugs at connection points to bond tray sections. Independent Grounding Lines: In critical installations (e.g., industrial facilities, rail systems, solar plants), separate grounding conductors can be installed using braided copper or galvanized conductors with grounding clamps at specified intervals.

Installation Steps

Select the Right Material: Use copper, hot-dip galvanized steel, or stainless steel for corrosion resistance and conductivity. Bonding Connections: Secure the grounding wire to each tray section using grounding clamps, bolts, or welds. For aluminum trays, avoid bare copper to prevent electrolytic corrosion; use insulated conductors with insulation removed only at bonding points.

Parallel Routing: Lay grounding conductors parallel to the cables in the tray. Connect cable shields or screens to the grounding system at both ends. Check Resistance: Ensure the grounding system has low resistance, ideally 4 ohms or less, to provide effective fault current paths.

Safety and Compliance

Keep grounding wires away from flammable, corrosive, or moist environments.

Follow NE

C standards for tray fill, cable separation, and grounding conductor sizing (NEC Table 250. 122 and Table 392. 60) to ensure safety and inspection compliance.

Verify that all connections are mechanically secure to withstand fault currents and magnetic forces. By following these steps, you ensure that the cable tray grounding system is safe, reliable, and compliant with electrical codes, reducing the risk of electrical hazards and improving system stability.