Cable tray reducing tees are specialized fittings that allow a smooth transition between different tray widths, available in horizontal and vertical configurations, with various materials and NEMA compatibility.

Overview

A reducing tee is a cable tray fitting used to branch a main tray run into a smaller or different-width tray, maintaining structural integrity and smooth cable routing. These fittings are essential in industrial and commercial installations where cable management requires transitions between different tray sizes.

Types and Configurations

• Horizontal Reducing Tee: Connects a main tray to a branch tray at the same horizontal plane. Ideal for long-span installations with large-diameter cables. Features include structural offsets for strong mid-span splices and reduced hardware requirements, allowing faster installation (up to 30% faster in some aluminum I-beam designs) .
• Vertical Reducing Tee: Allows branching at different vertical levels, useful for multi-level cable routing in congested areas .

Material and Construction

• Aluminum I-beam: Lightweight, corrosion-resistant, suitable for long spans and industrial environments .
• Steel (Hot-dip galvanized or bare): Provides high strength and durability, often used in heavy-duty applications .
• MIG welded or fabricated steel: Ensures structural integrity for high-load installations .

NEMA Compatibility and Classes

Reducing tees are designed to match standard NEMA cable tray classes:

• Class 1: For NEMA 12B and 12C trays, 1-1/8″ side rail flanges, 4-hole splice plates.
• Class 2: For NEMA 20A, 20B, 20C trays, 2″ side rail flanges, 4-hole splice plates.
• Class 3: For trays exceeding 20C, 2 3/8″ side rail flanges, 8-hole splice plates.
• Class 4: Heavy-duty trays like A820E, 2 3/4″ side rail flanges, 8-hole splice plates .

Dimensions and Sizes

• Heights typically range from 50mm to 120mm, with widths corresponding to the main and branch tray sizes .
• Splice plates and bolts are designed to minimize installation time and hardware usage, often requiring only four bolts per splice .

Design and Installation Features

• Smooth transition between straight sections and branch trays reduces cable stress.
• Mid-span splices provide structural strength with fewer supports.
• CAD/BIM models are available for design integration, supporting multiple formats for 2D and 3D planning .
• Compliance with standards such as ANSI/NFPA 70, ASTM A123, ISO 1461, and UL certifications ensures safety and reliability .

Popular Models and Manufacturers

• Eaton B-Line Series: Offers a wide range of metallic ladder and tray fittings with submittal builder tools for selection .
• Atkore I-Beam Ladder Horizontal Reducing Tee: Compatible with NEMA standard trays, available in multiple classes .
• Legrand ITray Horizontal Reducing Tee: Aluminum I-beam design for industrial installations, optimized for long spans and large cables .
• ABB T&B Cabletray Fittings: Steel and aluminum options with CAD/BIM support and compliance with ASTM and ISO standards . These specifications and models allow engineers and designers to select the appropriate reducing tee based on load requirements, tray width, material preference, and installation environment, ensuring efficient and safe cable management.