Principles of merging cable trays for low-voltage systems

When merging cable trays for low-voltage systems, maintain proper separation, spacing, and routing to minimize interference, ensure safety, and allow for future expansion. Separation of CablesLow-voltage systems, including data, control, and instrumentation cables, should be segregated from high-voltage power cables. Typically, electrical trays are positioned above instrumentation or low-voltage trays to reduce electromagnetic interference (EMI) and preserve signal integrity.

Where space constraints exist, metal partitions or dividers can be used to maintain separation and prevent interference in dense cabling environments.

Minimum Spacing

Industry standards recommend a minimum vertical and horizontal distance of 300mm (12 inches) between power and low-voltage trays. This spacing helps reduce EMI and ensures safe operation. In cases where trays must converge or run parallel, maintaining this minimum distance or using physical barriers is critical.

Tray Selection and Material

Choose a tray type that balances strength, ventilation, protection, and flexibility. Common options include: Cable ladders: Provide high strength, excellent ventilation, and easy access for maintenance. Ideal for heavier bundles or future expansion.

Wire mesh trays: Lightweight, flexible, and suitable for complex routing with multiple bends. Solid or ventilated trays: Protect sensitive cables from dust or mechanical damage while allowing airflow to prevent heat buildup. Materials should be selected based on environmental conditions, with steel, stainless steel, or aluminum commonly used for corrosion resistance and mechanical strength.

Routing and Bend Considerations

Cable trays should follow straightforward, shortest practical routes to minimize unnecessary bends and junctions. Respect the minimum bend radius of low-voltage cables, especially fiber optics and high-grade copper, to prevent signal degradation or physical damage. When merging trays, ensure that bends, T-junctions, or crossovers do not pinch or stress cables.

Load and Expansion Planning

Calculate the total weight and quantity of cables, including a 20–30% growth margin for future expansion. Ensure that the merged tray system can support the combined load without sagging or compromising structural integrity. Use proper support elements such as wall brackets, suspended supports, or center suspensions to maintain stability.

Safety and Maintenance

Avoid overcrowding trays to allow airflow and reduce heat buildup. Use covers or barriers to protect cables from mechanical damage. Maintain clear access for inspection and maintenance.

Follow relevant standards such as DIN EN 61537 for cable support systems. By adhering to these principles—separation, spacing, proper tray selection, careful routing, and load planning—low-voltage cable trays can be merged efficiently while ensuring system reliability, safety, and scalability.