Yes, cable trays can be placed on the ground, but proper grounding, support, and environmental considerations must be followed.

Ground Placement Considerations

Cable trays are versatile and can be installed in various locations, including on the floor, provided they remain accessible for maintenance and comply with safety standards . There are no explicit restrictions in the NEC against placing trays on the ground, but certain precautions are necessary:

• Accessibility: Trays must remain accessible for inspection, maintenance, and cable addition or removal .
• Environmental Protection: Ground-level installations may expose trays to moisture, dust, or mechanical damage. Using corrosion-resistant materials like aluminum or coated steel is recommended, and non-metallic trays can be considered in wet environments .
• Support and Stability: Even on the ground, trays should be properly supported to prevent sagging or movement. Supports or spacers can help maintain alignment and prevent direct contact with wet surfaces .

Grounding Requirements

Metallic cable trays must be grounded to ensure safety, even if they are not used as the equipment grounding conductor (EGC), . Key points include:

• Bonding: Sections of metallic trays should be bonded together using clamps or connectors to maintain electrical continuity .
• EGC Use: In qualifying installations, the tray itself can serve as the EGC if it meets cross-sectional area requirements, but a separate EGC conductor is often recommended for added safety .
• Material Considerations: Avoid placing bare copper conductors in aluminum trays in moist environments to prevent electrolytic corrosion; insulated conductors with proper bonding are preferred .

Practical Recommendations

• Cable Type: Only use tray-rated cables suitable for open-air or exposed environments .
• Separation: Maintain separation between high-power and low-power cables to reduce electromagnetic interference (EMI), .
• Fill Limits: Do not exceed the recommended fill capacity (typically 40–50% of tray cross-section) to prevent overheating .
• Maintenance: Ensure that trays on the ground are not obstructed by equipment or foot traffic to allow safe access for inspection and cable work . In summary, placing cable trays on the ground is permissible if proper grounding, material selection, support, and accessibility are ensured. Following NEC guidelines and best practices will maintain safety, reliability, and compliance with electrical codes .