How large should the gaps in the cable trays be

Cable tray gap sizes typically range from 6 to 18 inches for rungs, with horizontal and vertical spacing between trays of at least 0. 5 to 0. 6 meters, and support spans from 1.

5 to 3 meters depending on load and cable type.

Rung Spacing

For ladder-type cable trays, the rungs are spaced to support cables without excessive sagging. Typical rung spacings are 6, 9, 12, or 18 inches. Smaller spacings (6–12 inches) are recommended for small-diameter control and instrumentation cables, while larger spacings (9 inches or more) are suitable for large power cables.

Wider rung spacing reduces overall tray strength, so load capacity must be considered when selecting spacing.

Horizontal and Vertical Tray Spacing

When installing parallel cable trays, the minimum horizontal distance should be 0. 6 meters to allow maintenance, inspection, and proper airflow for heat dissipation. For power and signal trays, a minimum separation of 0.

5 meters is recommended to reduce electromagnetic interference (EMI), which can be reduced further to 0. 3 meters if the trays are shielded. Vertical spacing between floor-mounted trays or between upper and lower trays should be at least 150 millimeters to prevent obstruction and allow future cable installation.

Support Span

The distance between supports for straight horizontal runs typically ranges from 1. 5 to 3 meters, depending on tray type, cable load, and environmental conditions. Short-span trays are often supported every 6–8 feet, intermediate spans every 10–12 feet, and long spans up to 20 feet or more for outdoor or heavy-duty installations.

Summary

Rung spacing: 6–18 inches (smaller for control cables, larger for power cables)Horizontal spacing between trays: ≥0. 6 metersSeparation between power and signal trays: ≥0. 5 meters (≥0.

3 meters if shielded)Vertical spacing: ≥150 millimetersSupport span: 1. 5–3 meters (adjust based on load and tray type) These guidelines ensure structural integrity, proper cable support, heat dissipation, and reduced EMI, while allowing safe access for maintenance and future expansion.