Galvanized flat iron inside the cable tray

Galvanized flat iron can be safely laid inside a cable tray if properly supported, insulated, and fastened according to standard installation practices.

Material and Corrosion Considerations

Galvanized flat iron (GI) is commonly used in cable tray installations due to its corrosion resistance. The zinc coating provides sacrificial protection, forming a protective oxide layer that slows corrosion over time, especially in wet or humid environments. The corrosion resistance is proportional to the thickness of the galvanization, and small scratches or cuts in the coating will still be protected by the surrounding zinc layer (patina) .

Support and Fastening

When laying galvanized flat iron inside a cable tray, it is essential to ensure proper mechanical support. Supports such as MS angles or C-channels are typically fabricated and installed at regular intervals (e.g., 1 meter) to maintain stability and prevent sagging . Fastening should use high-tensile bolts, washers, and nuts, with hardware sets (e.g., M8) for joints and couplers. Splice plates should be positioned on the outside of the tray with bolt heads inside, and no more than one splice should be located between two adjacent supports .

Insulation and Safety

To prevent electrical contact and potential short circuits, the flat iron should be isolated from the cable tray supports using insulating materials such as G-10 sheets or FRP pieces at each support point. This ensures that the metallic flat iron does not directly contact other conductive parts . Additionally, care should be taken to avoid scratching the insulation of any cables during installation, using rollers or other protective measures when laying cables over the flat iron .

Spacing and Clearance

Maintain adequate clearance above the cable tray (minimum 300 mm) and ensure the tray is properly elevated from the floor (e.g., 2.67 m in substations) to allow for cable management and future additions . Supports should be strong enough to handle the weight of the flat iron and any cables, including future load increases.

Summary

• Use galvanized flat iron for corrosion resistance.
• Support the flat iron with MS angles or C-channels at regular intervals.
• Fasten securely with high-tensile bolts and splice plates.
• Insulate contact points with G-10 or FRP sheets.
• Maintain proper clearance and spacing for safety and future cable additions. Following these practices ensures that galvanized flat iron can be safely and effectively integrated into cable tray systems while maintaining mechanical stability and electrical safety .