Cable tray modification and elevation

Cable tray elevation can be adjusted using pre-fabricated drops, universal hooks, threaded rods, or software-based elevation settings to ensure proper alignment and grounding.

Physical Adjustment Methods

Using Drops and Universal Hooks: Elevation changes can be made with pre-fabricated drops or straight sections equipped with universal hooks and extenders. These allow adjustments of up to 6 inches per end without cutting the tray, preserving grounding continuity and UL classification. The drop acts as a hinge; the desired angle is set, bolts are inserted, and hex flanged nuts are tightened. Powder-coated areas should be scraped to maintain electrical grounding continuity . Offset Loops and Lateral Adjustments: For sections that do not align perfectly, offset loops can be bolted to existing loops, allowing lateral adjustments up to 12 inches. This method also enables lengthening of tray drops while maintaining proper contact surface alignment . Threaded Rods and Hanger Clamps: Elevation benchmarks can be transferred using a laser level or transit. Threaded rods are pre-threaded with hex nuts, and clamps are positioned around the tray siderails. By adjusting the nuts, the tray is lifted to the desired elevation. Horizontal adjustments are limited by the length of the vertical rods, so proper positioning is critical .

Software-Based Adjustment

Revit and Design Software: In CAD or BIM software like Revit, cable tray elevation can be adjusted by editing the start or end elevation of the tray. The align tool can then be used to match the tray to sloping ceilings or framing. Design Master Software allows specifying starting and ending elevations relative to the center, top, or bottom of the tray, as well as vertical alignment for hangers .

Best Practices

• Always establish an elevation benchmark before installation to ensure consistency along the tray run .
• Avoid cutting trays unless absolutely necessary, as this can compromise grounding and UL compliance .
• Ensure all hardware and pre-fabricated components are compatible and installed according to manufacturer guidelines .
• Maintain grounding continuity by scraping powder-coated areas where hardware attaches .
• Use laser levels, string lines, or baling wire to verify alignment during installation . By combining these physical and software-based methods, cable trays can be accurately positioned, aligned with sloping surfaces, and safely installed while maintaining electrical and structural integrity.