Cable tray support installation spacing requirements

Cable tray supports should be spaced according to tray type, span, and load, typically ranging from 6 to 20 feet for horizontal runs and less than 2 meters for vertical runs.

Horizontal Cable Tray Support Spacing

• Short Span Trays: Typically supported every 6 to 8 feet, suitable for non-industrial indoor installations .
• Intermediate Span Trays: Supported every 10 to 12 feet, commonly used in standard industrial applications .
• Long Span Trays: Supported every 14 to 20 feet, with 20 feet being the most common for heavy-duty or outdoor installations .
• Extra-Long Span Trays: Supports may exceed 20 feet, often used outdoors to cross roads or reduce the number of supports . Support placement should align with splice plate locations, ensuring only one splice plate per support span to maintain structural integrity . The tray length must be equal to or longer than the selected support span.

Vertical Cable Tray Support Spacing

• Vertical runs should be supported at the top and at intervals preferably less than 2 meters to prevent sagging and maintain cable stability .
• Cables within vertical trays should be secured at the top and every 1.5 meters to ensure proper organization and safety .

Key Support Locations

Supports must be installed at critical points, including:

• Tray beginnings and ends
• Corners and T-junctions
• Spans exceeding 30 meters
• Transitions to equipment or other raceways

Additional Considerations

• Cable Securing: Horizontal runs should have cables secured at start, end, turns, and every 3 to 5 meters along straight sections .
• Binding: Cable ties should not exceed 1.5 meters apart to maintain even tension .
• Clearances: Maintain at least 12 inches of vertical clearance above trays for installation and maintenance access .
• Load and Material: Support spacing must consider the tray's load capacity, material, and environmental conditions . Following these guidelines ensures structural stability, prevents sagging, allows proper heat dissipation, and maintains compliance with NEC and manufacturer standards. Properly spaced supports also facilitate maintenance, inspection, and future expansion.