Specifications and Length of Metal Cable Trays

Metal cable trays are standardized systems with widths from 50mm to 900mm, depths from 50mm to 150mm, and lengths typically of 3 meters, made from materials like galvanized steel, stainless steel, or aluminum.

Standard Dimensions

• Width: 50mm to 900mm, chosen based on the number of cables to be installed side-by-side .
• Depth (Height of Side Walls): 50mm to 150mm, ensuring cables are securely held and allowing proper airflow .
• Length: Most trays come in 3-meter (10-foot) sections, which balance ease of transport and installation .
• Rung Spacing (for ladder-type trays): Typically 6 to 12 inches (150 to 300 mm), with radius fittings often at 9 inches at the center of the tray width .
• Cable Fill: Recommended to fill only 40% of tray capacity to allow heat dissipation and future expansion .

Material and Construction

• Galvanized Steel: Economical, corrosion-resistant, suitable for most industrial and commercial environments .
• Stainless Steel (AISI 316L): High corrosion resistance, ideal for harsh or chemical environments .
• Aluminum: Lightweight, corrosion-resistant, and easy to form, suitable for indoor and outdoor applications .
• Wire Mesh (Flextray): High-strength steel wire, used for light-duty or instrumentation cables .

Structural and Mechanical Specifications

• Side Rails and Rungs: Ladder trays have two longitudinal side rails with transverse rungs welded or bolted, complying with NEMA VE 1 standards .
• Splice Connections: Bolted type using serrated flange locknuts; resistance of fixed splice connections typically ≤ 0.00033 ohm .
• Minimum Cable-Bearing Surface: Rungs usually have at least 7/8 inch width with radius edges to prevent cable damage .
• Load Capacity: Varies by tray type and material; heavy-duty trays (Series 2–5) support higher loads, while light-duty trays (NEMA 12A/12B) are for smaller installations .

Additional Considerations

• Ventilation: Ventilated or ladder trays allow heat dissipation; solid-bottom trays are used where aesthetics or minimal heat generation is required .
• Compliance: Metal cable trays are designed to meet NEC, NEMA, and IEC standards, and are often UL-listed for safety and grounding purposes .
• Future Expansion: Proper sizing ensures additional cables can be added without replacing the tray system . By selecting the correct width, depth, material, and rung spacing, metal cable trays provide a safe, code-compliant, and expandable solution for cable management in industrial, commercial, and data center environments.