Cables in a tray should be arranged by type, size, and function, with proper separation, support, and routing to ensure safety, accessibility, and compliance with standards.

General Principles

1. Segregation by Cable Type Power, control, and data cables should be separated to prevent electromagnetic interference and maintain safety. High-voltage cables are typically placed on one side of the tray, while low-voltage or sensitive instrumentation cables are routed separately .
2. Load Distribution Arrange cables to evenly distribute weight across the tray. Heavier cables should be placed at the bottom or center of ladder trays, while lighter cables can be positioned on top or sides . This prevents tray deformation and ensures mechanical stability.
3. Routing and Bend Radius Maintain the minimum bend radius for each cable type to avoid damage. Gradual bends are preferred, and sharp turns should be avoided. Use horizontal and vertical fittings such as bends, T-pieces, and crossovers to guide cables smoothly .
4. Layering and Grouping Cables can be grouped by function or destination. For example, all cables going to a specific panel or device can be bundled together. Avoid excessive stacking to prevent overheating and allow airflow .
5. Support and Securing Use support elements like wall brackets, suspended supports, or center suspensions to secure trays. Cables should be fastened with ties or clamps at regular intervals to prevent sagging and maintain spacing .
6. Use of Covers and Barriers Solid or ventilated covers can protect cables from dust, moisture, and mechanical damage. Barrier strips or dividers can separate different cable types within the same tray .
7. Compliance with Standards Follow local electrical codes and manufacturer guidelines for spacing, load class, and installation practices. Ensure that trays are mounted securely to floors, walls, ceilings, or equipment racks as required .

Practical Example

• Bottom Layer: Heavy power cables
• Middle Layer: Medium-voltage or control cables
• Top Layer: Low-voltage, instrumentation, or data cables
• Side Separation: Use dividers for sensitive or critical cables
• Fittings: Horizontal and vertical bends to maintain smooth routing
• Supports: Brackets or hangers every 1.5–3 meters depending on tray type and load By following this arrangement order, cable trays maintain mechanical integrity, thermal performance, and accessibility for maintenance and future expansion .