Cable tray elbow tee dimensions and specifications

Cable tray elbows and tees are standardized fittings designed to match the width, depth, and material specifications of straight tray sections, with radii and tangent lengths defined for smooth cable routing.

Standard Dimensions

• Widths: Cable tray elbows and tees are available in standard widths corresponding to straight tray sections, typically 6, 9, 12, 18, 24, 30, and 36 inches (nominal inside usable width) to ensure compatibility with the main cable run .
• Heights/Depths: Side rail heights (tray depth) commonly range from 50 mm to 120 mm, depending on the cable load and type of tray .
• Radii: Radiused fittings, including elbows, generally have a minimum radius of 12, 24, 36, or 48 inches, measured at the center of the tray width, to allow smooth cable bending without damage .
• Tangent Length: All fittings must have a minimum tangent of 3 inches to facilitate proper alignment with straight sections .

Material Specifications

• Steel Types: Common materials include hot-dip galvanized steel, stainless steel, and powder-coated steel for durability and corrosion resistance .
• Standards Compliance: Fittings comply with ANSI/NFPA 70 (NEC), NEMA VE 1, ASTM A123, A653, A1011, A1008, and B633 for structural and coating quality .

Load and Structural Requirements

• Rungs: For ladder-type trays, rungs must have a minimum cable bearing surface of 7/8 inch with radiused edges, and no portion should protrude below the side rails .
• Load Capacity: Each rung must support the cable load with a safety factor of 1.5 and withstand a 200 lb concentrated load during testing .

Tee Fittings

• Configuration: Tee fittings allow branching of cable runs at 90° angles, maintaining the same width as the main tray or a reduced width if specified.
• Compatibility: Tees are manufactured to match the side rail height, material, and thickness of the connecting trays, ensuring structural integrity and proper cable support .

Summary

Cable tray elbows and tees are engineered to provide smooth cable transitions, maintain NEC fill compliance, and support structural loads. When selecting these fittings, ensure the width, depth, radius, material, and tangent length match the straight tray sections, and verify compliance with NEMA, ASTM, and NEC standards for safety and durability .