How to get low-voltage secondary piping into cable trays

Low-voltage secondary piping should be routed in dedicated or properly separated cable trays with adequate support, shielding, and spacing to prevent interference and ensure safe, maintainable installations.

Tray Selection and Separation

For low-voltage secondary piping, such as instrumentation or control conduits, it is critical to use dedicated trays or compartments separate from high-voltage power cables to avoid electromagnetic interference (EMI) and signal degradation. If sharing trays is unavoidable, maintain physical separation and consider shielded conduits to protect sensitive signals. Common tray types include: Ladder trays: Ideal for long runs requiring ventilation and easy access for multi-core cables.

Perforated trays: Suitable for medium loads, providing some protection while allowing airflow. Solid-bottom trays: Recommended for delicate instrumentation cables exposed to EMI or corrosive environments.

Routing and Support

Maintain minimum bend radius for piping and cables to prevent mechanical stress and signal loss. Plan routing in advance, including junction boxes (JBs) and Distributed Control System (DCS) panels, to avoid complex retrofits. Leave 30–40% of tray space free for future expansion.

Use support elements such as wall brackets, suspended supports, or center suspensions to secure piping within the tray. Ensure piping does not obstruct cable access for maintenance or future upgrades.

Environmental and Safety Considerations

In corrosive or humid environments, use stainless steel trays or trays with protective coatings. Avoid routing piping that carries hot fluids directly over low-voltage trays to prevent heat damage; if unavoidable, use insulation or heat shields. Ensure proper grounding and bonding of trays to maintain electrical safety and reduce EMI.

Practical Tips

Route piping under trays when possible to simplify maintenance and reduce the risk of leaks affecting cables. Use cable ties, clamps, or barrier strips to secure piping and maintain organized separation from cables.

Follow NE

C Article 392 and local codes for tray fill, spacing, and installation standards. By following these practices, low-voltage secondary piping can be safely integrated into cable tray systems while minimizing interference, mechanical stress, and maintenance challenges.