Galvanized cable trays do not require grounding bridging at the connecting plate ends, but proper mechanical connections with anti-loosening hardware are recommended.

Mechanical Connection

For galvanized cable trays, bridging is generally not required for grounding purposes at the ends of connecting plates. Each end of the connecting plate should, however, be secured with at least two fixing bolts using anti-loosening nuts or washers to maintain structural integrity and prevent movement of the trays . This ensures the trays remain mechanically stable without the need for additional bridging for electrical continuity.

Electrical Considerations

Unlike stainless steel or aluminum alloy trays, galvanized trays do not require dedicated grounding bolt holes for bridging at the connection points . Conductive connections can be achieved using galvanized steel bolts with anti-loosening gaskets or, alternatively, insulated multi-strand copper wires with crimped tinned copper connectors if cross-connection is needed. The cross-sectional area of the copper wire should be greater than 4.0 mm² to ensure proper conductivity .

Installation Best Practices

• Use anti-loosening nuts or washers provided by the manufacturer to secure bolts. Avoid using only anti-loosening washers without nuts for convenience .
• Ensure that the rung spacing and tray support are appropriate for the cable type and load to prevent sagging or excessive deflection .
• For stainless steel or aluminum trays, special grounding bolt holes are required, but this is not necessary for galvanized trays .

Summary

In summary, galvanized cable trays do not require bridging for grounding at the connecting plate ends, but proper mechanical fastening with anti-loosening hardware is essential. Bridging may still be used in specific applications for structural reinforcement or cross-connection, but it is not a mandatory requirement for electrical continuity in galvanized systems .