Can cables and conductors be stored in cable trays

Yes, cables and conductors can be stored in cable trays, provided they are properly rated, supported, and installed according to electrical codes and manufacturer guidelines.

Cable Tray Usage

Cable trays are designed to support insulated conductors and cables in commercial, industrial, and process installations, offering mechanical support, organization, and accessibility for maintenance or future expansion. They are suitable for power, control, instrumentation, and communication cables when installed correctly.

Types of Cables Permitted

Only cables rated for open-air environments should be installed in cable trays. Common types include: Tray Cable (Type TC): Factory-assembled insulated conductors under a non-metallic jacket, rated for 600 volts, suitable for industrial power or control circuits.

Metal-

Clad Cable (Type MC): Insulated conductors enclosed in metal armor, suitable for indoor/outdoor use, wet or dry locations, and hazardous areas. Instrumentation Tray Cable (Type ITC): Shielded or unshielded cables for control and instrumentation applications. All cables must be UL listed and marked as cable tray rated to ensure compliance with safety and performance standards.

Installation Requirements

Support and Securement: Cables must be secured at intervals according to manufacturer instructions, typically not exceeding six feet for TC-ER or MC cables. Fill Limits: Power cables should not exceed 40% of the tray's cross-sectional area, and control cables should not exceed 50% to prevent overheating. Separation: High-power and low-power cables must be separated to avoid electromagnetic interference, either by spacing or solid barriers.

Clearances: Maintain at least 12 inches of vertical clearance above trays for installation and maintenance access. Prohibited Areas: Cable trays should not be installed in hoistways or enclosed spaces and must remain accessible for inspection.

Best Practices

Use sunlight-resistant cables for outdoor installations and expansion splice plates to accommodate thermal expansion. Ensure proper grounding and bonding for metallic trays to serve as equipment grounding conductors if required. Avoid overloading trays and maintain proper bend radius for cables exiting the tray to prevent damage.

In summary, cables and conductors can be stored in cable trays as long as they are rated for tray use, properly supported, secured, and installed in compliance with NEC Article 392 and manufacturer guidelines. This ensures safety, accessibility, and long-term reliability of the electrical system.