Cable Tray Model Designation Diagram

Cable trays are engineered support systems for electrical and data cables, available in various types, materials, and load capacities, with detailed specifications and modular diagrams for installation.

Types of Cable Trays

1. Ladder Tray: Features side rails connected by rungs, ideal for heavy-duty cables and long runs. Provides excellent ventilation and strain relief. Commonly used in data centers and industrial applications (Hubbell NEXTFRAME® Ladder Tray) .
2. Solid Bottom Tray: Offers full support for cables, reducing dust accumulation and protecting sensitive instrumentation cables. Suitable for areas with minimal heat buildup .
3. Ventilated Tray: Has perforated or slotted bottoms to allow airflow, preventing overheating of cables .
4. Wire Mesh Tray (Cable Basket): Lightweight, flexible, and easy to install, suitable for light cabling and complex routing .
5. Channel Tray: Compact, used for short runs or aesthetic applications where visibility is important .

Materials and Finishes

• Steel: Pre-galvanized or hot-dip galvanized for corrosion resistance.
• Stainless Steel: AISI 316L for high corrosion resistance, especially in chemical or marine environments.
• Aluminum: Lightweight, corrosion-resistant, and suitable for indoor and outdoor use.
• Fiberglass Reinforced Polyester (FRP): High resistance-to-weight ratio, excellent for corrosive environments .

Load Classes and Dimensions

• Load Class: Defines the maximum load a tray can carry over a specific support span. Commonly classified as light, medium, or heavy duty.
• Width: Measured outside-to-outside; typical widths range from 50 mm to 600 mm.
• Rung Spacing: Ladder trays typically have 150–230 mm spacing to support cables and maintain bend radius .
• Height: Side rail height varies depending on load requirements.

Fittings and Accessories

• Horizontal and Vertical Bends: Allow routing around obstacles.
• Splice Plates: Standard, expansion, or adjustable for connecting tray sections.
• Risers and Tees: For vertical transitions and branching.
• Covers: Solid or ventilated to protect cables and reduce electromagnetic interference.
• Mounting Hardware: Brackets, J-bolts, and universal supports for floors, walls, ceilings, and equipment racks .

Model Diagrams and Installation

Cable tray systems are modular and can be represented in CAD, BIM, or PDF diagrams. These diagrams typically include:

• Straight sections, bends, tees, and risers.
• Dimensions, load ratings, and material specifications.
• Recommended support spacing and installation orientation.
• Visual representation of cable routing and bend radius compliance . Manufacturers like Legrand, Hubbell, Eaton, ABB, and Swift provide downloadable catalogs and submittal tools to generate BOMs, CAD drawings, and model diagrams for specific projects, ensuring proper selection and installation .

Key Considerations

• Verify load capacity and support span for the intended cable weight.
• Select material and finish based on environmental conditions.
• Maintain minimum bend radius to prevent cable damage.
• Ensure compliance with standards such as UL, NEMA, CE, and ISO environmental labels .
• Use modular fittings to allow future expansion or reconfiguration. By following these specifications and using manufacturer-provided diagrams, engineers and contractors can design safe, efficient, and code-compliant cable tray installations.