How to install copper plates on cable trays

Copper plates are used on cable trays primarily for grounding and bonding, ensuring electrical continuity and safety while preventing corrosion.Purpose of Copper Plates

Copper plates or strips are often installed on cable trays to serve as bonding conductors or to enhance the tray's role as an Equipment Grounding Conductor (EGC). They provide a low-resistance path for fault currents, ensuring that all sections of the tray are electrically continuous and safely connected to the building's main earth ground .

Installation Guidelines

1. Material Compatibility: Avoid placing bare copper directly in aluminum trays in moist environments due to the risk of electrolytic corrosion. If aluminum trays are used, copper should be insulated, with insulation removed only at bonding points using tin or zinc-plated connectors .
2. Bonding Across Sections: Install copper plates or bonding jumpers across every splice or joint if the tray couplers are not rated for grounding continuity. This ensures electrical continuity and mechanical stability under fault conditions .
3. Connection Points: Copper plates should be securely fastened to the tray using grounding clamps or bolts, ensuring a solid electrical connection to side rails, raceways, or equipment enclosures .
4. Sizing: The cross-sectional area of copper plates should meet the minimum requirements for the tray to function as an EGC, based on the expected fault current and breaker ratings. Refer to NEC Table 392.60(A) for guidance .
5. System Grounding: Connect the copper plates to the main building earth ground at a designated point to complete the grounding system .

Safety and Best Practices

• Ensure all personnel are qualified and follow PPE requirements during installation .
• Maintain proper support spacing and tray alignment to prevent mechanical stress on copper plates.
• Inspect connections periodically to ensure continuity and corrosion protection.
• Use insulated copper conductors where direct contact with dissimilar metals could cause corrosion.

Summary

Proper installation of copper plates on cable trays enhances electrical safety, fault protection, and system reliability. Key considerations include material compatibility, secure bonding across tray sections, correct sizing, and connection to the main ground. Following these practices ensures compliance with NEC and local electrical codes while preventing corrosion and maintaining long-term system integrity .