Cable trays must be supported using properly sized hanger rods or angle irons, spaced according to tray type, load, and applicable standards such as NEMA VE 1 and BS EN 61537.

Hanger Rods

Hanger rods are vertical supports used to suspend cable trays from ceilings or structural members. Key specifications include:

• Material: Typically steel, stainless steel, or galvanized steel to resist corrosion and provide adequate strength .
• Diameter: Commonly 10–12 mm (3/8–1/2 inch) for standard loads; larger diameters may be required for heavy-duty trays or long spans .
• Spacing: Maximum spacing depends on tray type and load:
  • Ladder-type trays: 1.5–3 meters (5–10 feet) between hangers.
  • Solid-bottom or trough-type trays: 1–2 meters (3–6 feet) between hangers .
• Attachment: Hanger rods are connected to the tray using clamps, brackets, or threaded inserts, ensuring secure load transfer without damaging the tray .

Angle Irons

Angle irons are horizontal or vertical support members used to mount trays to walls, beams, or other structures:

• Material: Steel or stainless steel, often hot-dip galvanized for corrosion protection .
• Dimensions: Common sizes range from 40×40×4 mm to 50×50×6 mm, depending on tray width and load .
• Mounting: Angle irons can be used as wall brackets, ceiling supports, or cross members. They are typically bolted or welded to structural elements and provide a stable base for tray attachment .
• Spacing: Similar to hanger rods, spacing is determined by tray type, load, and span. For heavy cable loads, closer spacing is recommended to prevent sagging .

Compliance and Standards

• NEMA VE 1: Defines metallic cable tray systems, including load ratings, material specifications, and installation practices .
• NEC Article 392: Covers installation requirements for cable trays in the United States, including support intervals and grounding .
• BS EN 61537: European standard for cable management systems, specifying mechanical and environmental requirements .
• UL and NFPA Compliance: Ensure that trays, hangers, and fittings are UL-listed and meet NFPA 70B recommendations for electrical equipment maintenance .

Practical Recommendations

• Always use manufacturer-approved components for hangers, brackets, and angle irons to maintain system integrity .
• Verify load ratings for both the tray and support elements, considering cable weight and potential short-circuit forces .
• Maintain proper alignment and level to prevent cable stress and ensure safe routing.
• For long spans or heavy loads, consider intermediate supports or reinforced angle irons to reduce deflection . By following these specifications, cable tray systems can be safely and efficiently installed, providing reliable support for electrical and communication cables while complying with relevant standards.