Can low-voltage wires be laid in cable trays

Yes, low-voltage wiring can be run through cable trays, provided the installation follows NEC guidelines and proper separation from higher-voltage cables is maintained.

NEC Compliance and Cable Tray Use

Cable trays are designed as support systems for various wiring types, including low-voltage systems such as communications, control, and signaling circuits (NEC Article 392.3) . Low-voltage cables rated 600 volts or less can be installed together in the same tray without additional separation, as long as tray fill, support, and securement requirements are met . For cables operating above 600 volts, a solid barrier or separate tray is required to prevent interference and maintain safety .

Cable Tray Selection for Low-Voltage Systems

When selecting a tray for low-voltage wiring, consider the following factors :

• Cable Type and Diameter: Include Cat6/6A/7, fiber optic, coaxial, and control cables, noting their outer diameters.
• Total Quantity and Weight: Plan for current and future expansion, typically adding 20–30% growth margin.
• Bend Radius: Ensure the tray accommodates the minimum bend radius for fiber optics and copper cables to prevent damage.
• Tray Design: Ladder trays provide strength, ventilation, and easy access, while solid-bottom trays may be used for additional protection in high-traffic areas.

Installation Best Practices

• Securement: Cables must be fastened at intervals according to manufacturer instructions, especially on non-horizontal runs .
• Separation: Maintain separation between low-voltage and high-voltage cables when required, using barriers or separate trays .
• Accessibility: Ensure adequate space around trays for installation and maintenance, typically 12–18 inches between stacked trays .
• Protection: Covers are optional but recommended in high-traffic or outdoor areas to protect cables from physical damage and environmental exposure .

Summary

Low-voltage wiring can safely and effectively be run through cable trays if the installation adheres to NEC Article 392, uses appropriate tray types, maintains proper separation from higher-voltage circuits, and follows securement and support guidelines. Proper planning ensures system reliability, scalability, and compliance with electrical codes .