How to install and secure a vertical cable tray

Vertical cable trays must be installed with proper support, alignment, and compliance with NEC 392 to ensure safety, accessibility, and mechanical integrity.

Planning and Preparation

Before installation, review the approved shop drawings to determine the layout, length, and location of vertical cable trays in the building. Inspect all materials upon delivery to ensure they match the approved submittal and are free from damage. Store trays horizontally on a flat surface with timber supports at regular intervals to prevent warping or corrosion, and protect them from moisture and direct sunlight.

Material Selection

Choose the tray material based on environmental conditions and load requirements. Common options include aluminum, steel, or fiberglass-reinforced plastic (FRP).

FR

P is ideal for corrosive or high-moisture environments due to its non-conductive and corrosion-resistant properties. Ensure the trays conform to NEMA VE 1 standards for mechanical strength and load-bearing capacity.

Support Methods for Vertical Runs

Vertical cable trays are typically supported using cantilever wall brackets or trapeze hangers depending on the building structure. The support span must be calculated based on the manufacturer's load capacity chart and the anticipated weight of the cables. Proper support prevents sagging, mechanical stress, and potential damage to conductors.

Installation Steps

Mark and Align: Use a scribe or marking tool to mark the wall or support structure for bracket placement. Ensure vertical alignment to maintain a straight run. Install Brackets: Secure cantilever brackets or trapeze hangers at calculated intervals.

Verify that all supports are level and plumb. Mount Trays: Lift and attach the vertical tray sections to the supports. Use appropriate fasteners and ensure trays are securely anchored.

Connect Sections: Join tray sections using manufacturer-approved fittings, ensuring continuity and proper grounding if metallic trays are used. Cable Management: Route cables carefully, maintaining fill limits (40% for power cables, 50% for control cables) and separation between high-power and low-power circuits to prevent EMI. Avoid overfilling to prevent overheating and mechanical stress.

Safety and Compliance

Maintain at least 12 inches of vertical clearance above trays for installation and maintenance access. Metallic trays can serve as equipment grounding conductors if they meet NEC requirements. Do not install trays in hoistways or enclosed spaces; they must remain accessible.

Follow all local building codes, occupational health and safety procedures, and electrical codes (NEC or CEC) during installation.

Final Checks

After installation, inspect the system for proper alignment, secure fastening, and compliance with code requirements. Verify that all cables are supported, properly tied, and that grounding continuity is maintained. Document any deviations or adjustments for future maintenance.

By following these steps, vertical cable trays can be installed safely, efficiently, and in compliance with electrical standards, ensuring long-term reliability and ease of maintenance.