Cables in a two-layer cable tray should be organized by type, secured with appropriate ties or clamps, and spaced to maintain bend radius and airflow.

Organize and Classify Cables

Start by classifying cables by type and function. Power, control, and instrumentation cables should be separated to prevent interference and simplify maintenance. Place heavier power cables on the bottom layer and lighter control or instrumentation cables on the top layer to maintain stability and reduce stress on lower cables .

Maintain Proper Spacing and Bend Radius

Ensure adequate spacing between cables to prevent overheating and allow airflow. Use the tray rungs or separators to maintain consistent spacing. Respect the minimum bend radius for each cable type, especially at entry and exit points, to avoid conductor damage .

Use Securing Accessories

• Cable ties or Velcro straps: Secure cables at regular intervals along the tray rungs, typically every 6–9 inches (150–230 mm) for smaller cables .
• Cable clamps or brackets: For heavier cables or bundles, use clamps to prevent movement during short circuits or vibration .
• Separators or dividers: Install vertical or horizontal dividers to prevent cables from sagging or crossing layers, which helps maintain organization and reduces mechanical stress .

Layer Management

• Avoid overcrowding by calculating cable fill for each layer. Overfilled trays can cause overheating and make maintenance difficult .
• Keep the top layer accessible for inspection and future additions. Use removable covers if the tray design allows, ensuring protection without compromising access .

Grounding and Bonding

Ensure that the tray and all metallic components are properly grounded to prevent electrical hazards. Bonding the tray to the system ground also helps reduce electromagnetic interference between layers .

Regular Inspection and Maintenance

Periodically inspect the tray to check for loose ties, sagging cables, or damaged insulation. Adjust or replace securing devices as needed to maintain safety and compliance . By following these principles—classification, spacing, securing, and regular inspection—you can ensure that a two-layer cable tray installation is safe, organized, and compliant with electrical standards.