Spacing of ladder-type galvanized cable trays

Ladder-type galvanized cable trays typically use rung spacings of 6, 9, 12, or 18 inches, selected based on cable type, size, and load requirements.

Recommended Rung Spacing

• Small-diameter control and instrumentation cables: Use 6, 9, or 12-inch rung spacing to prevent excessive drooping and maintain neat installation. These cables are flexible and can span shorter distances without damage, but closer spacing improves appearance and support (Eaton B-Line series) .
• Large power cables: Use 9-inch or wider rung spacing. Wider spacing accommodates the larger cable diameters and allows proper bending radii as cables exit the tray, while still providing adequate support (Eaton B-Line series) .
• General guideline: A rung spacing of 6 to 9 inches (150–230 mm) is preferable for instrumentation and control applications requiring additional protection (ABB Technical Guide) .

Considerations for Tray Width and Load

• Wider trays (42–48 inches) may require stronger rungs or load reductions to maintain structural integrity, as wider rung spacing decreases overall tray strength (Eaton B-Line series) .
• Always verify the cable manufacturer's recommended minimum bending radius to avoid damage when cables exit the tray (Eaton B-Line series) .
• Ladder trays provide maximum airflow, reducing heat buildup and dust accumulation, which is particularly important for power cables carrying high current (Eaton B-Line series) .

Standards and Best Practices

• Ladder cable trays should comply with BS EN 61537 or equivalent standards for cable support systems (BEAMA Guide) .
• They are designed to support cables, not as walkways, and should be installed with compatible support elements and mounting hardware to ensure safety and stability (OBO CMS Guide) .
• Galvanized trays offer corrosion protection, and the thickness of the zinc coating affects durability in different environments (ABB Technical Guide) .

Summary

For ladder-type galvanized cable trays:

• 6–12 inches for small instrumentation/control cables
• 9–18 inches for large power cables
• Adjust rung spacing based on tray width, cable size, and load
• Ensure compliance with relevant standards and manufacturer recommendations
• Consider airflow, heat dissipation, and corrosion protection when selecting tray material and finish This approach ensures safe, neat, and durable cable installations while maintaining compliance with industry standards.