2018 National Standard Thickness of Cable Trays

The 2018 NEMA VE-2 standard specifies cable tray thickness based on material type, tray style, and load/span class, with typical steel tray thicknesses ranging from 12 to 16 gauge (≈2.0–2.5 mm) for commercial and industrial applications.Overview of NEMA StandardsThe National Electrical Manufacturers Association (NEMA) VE-1 and VE-2 standards define the manufacturing and installation requirements for metal cable trays, including ladder, ventilated trough, solid bottom, and channel types, as well as associated fittings. These standards ensure compliance with the National Electrical Code (NEC) and the Canadian Electrical Code (CEC), providing guidance on material thickness, load/span classes, and structural integrity .Material Thickness GuidelinesSteel Cable Trays: Typically, steel trays are manufactured in 12 to 16 gauge thickness, depending on the tray width, span, and load class. Heavier-duty trays designed for high-load industrial applications may use thicker steel to meet NEMA load/span requirements .Aluminum Cable Trays: Aluminum trays are generally lighter and may have slightly thinner walls than steel, but thickness is still determined by the load/span class specified in NEMA VE-2.Nonmetallic (Fiberglass) Trays: Governed by UL 568 and NEMA FG-1 (rescinded in 2017), these trays have thicknesses designed to meet mechanical and electrical performance requirements, with specific values provided in the manufacturer's datasheets .Load and Span ConsiderationsThe required thickness of a cable tray is influenced by:Tray width and depthMaximum allowable span between supportsLoad class (e.g., light, medium, heavy duty)Environmental factors such as temperature, corrosion, and vibration NEMA VE-2 provides tables correlating tray width, material, and load class to the minimum recommended thickness to ensure structural integrity and compliance with NEC installation rules.Practical NotesAlways verify the manufacturer's datasheet for the specific tray type, as thickness may vary slightly depending on design and material finish.For installations in corrosive or outdoor environments, consider trays with galvanized or stainless steel coatings, which may affect the effective thickness and load capacity .Support spacing should follow the 1/4 span rule recommended by NEMA VE-2 to minimize deflection and stress at splice locations . In summary, while the exact numeric thickness depends on tray type, material, and load class, the 2018 NEMA VE-2 standard provides comprehensive tables and guidelines to determine the appropriate thickness for safe and code-compliant cable tray installations.