Vertical Shaft Cable Tray Specifications and Dimensions

Vertical shaft cable trays typically follow standard widths of 6 to 48 inches and depths of 2 to 12 inches, with rung spacing and material thickness selected based on cable load and type.

Standard Widths and Depths

Vertical cable trays, often ladder or perforated types, are manufactured in nominal widths ranging from 6 inches to 48 inches. Common widths include 6, 9, 12, 18, 24, 30, 36, 42, and 48 inches, with the inside usable width slightly smaller than the outside dimension due to side rail thickness . The depth (side rail height) typically ranges from 2 inches to 12 inches, controlling vertical stacking capacity and influencing heat dissipation and NEC fill compliance . Increasing depth does not always increase usable capacity efficiently; often, increasing width provides better airflow and easier cable pulling.

Rung Spacing

For ladder-type vertical trays, rung spacing is critical to support cables and prevent sagging. Standard rung spacings are 6, 9, 12, or 18 inches, with smaller spacings recommended for small-diameter control and instrumentation cables, and wider spacings for large power cables .

Material Thickness

Material thickness affects load capacity and long-term durability. Typical thickness ranges vary by tray type and width, with thicker side rails and rungs required for wider trays or heavier cable loads .

Length and Support

Vertical trays are usually manufactured in standard lengths of 12, 20, 24, or 30 feet, though some manufacturers offer lengths up to 40 feet . Support intervals depend on the tray type and load, with short spans supported every 6–8 feet and longer spans up to 20 feet or more. Splice plates are used to connect sections, ensuring structural integrity.

Design Considerations

• Cable fill: Calculate based on outside cable diameter, not conductor size, and limit fill to a percentage of usable tray area (commonly 40%) to prevent overcrowding .
• Heat dissipation: Adequate depth and spacing ensure proper airflow.
• Compliance: Follow NEC, NEMA, and IEC standards for vertical installations .
• Load capacity: Consider both cable weight and environmental loads such as wind or seismic forces .

Summary

For vertical shaft installations, select a cable tray width and depth based on the total cable area, type, and load. Use appropriate rung spacing and material thickness to support the cables safely, and ensure compliance with relevant electrical codes. Standard widths range from 6–48 inches, depths from 2–12 inches, and rung spacing from 6–18 inches, with lengths and supports tailored to the building or industrial application .