Distance of cable tray fixing brackets

Cable tray fixing brackets should generally be installed every 1 to 1.5 meters, with closer spacing for heavier loads or horizontal runs.

Recommended Spacing

• Horizontal runs: Brackets are typically spaced every 300 mm to 400 mm for standard cables, but for heavier cable trays or long spans, spacing can extend up to 1 to 1.5 meters depending on tray type and load capacity .
• Vertical runs: Brackets can be spaced slightly further apart, generally 500 mm to 600 mm, as vertical orientation reduces sagging risk .
• Longer spans or heavy-duty trays: Some installations allow spacing up to 3 meters, but this requires careful assessment of tray material, cable weight, and environmental factors .

Factors Affecting Bracket Spacing

1. Cable Weight and Type: Heavier armoured or multi-core cables require closer bracket spacing to prevent sagging and strain on terminations . Lighter data cables can tolerate slightly wider spacing.
2. Tray Material and Strength: Steel, aluminum, or fiberglass trays have different load capacities. Manufacturer guidelines should be followed to ensure structural integrity .
3. Installation Environment: Vibration, wind, temperature fluctuations, or ceiling voids may necessitate closer bracket spacing to maintain stability .
4. Regulatory Compliance: Adherence to standards such as BS 7671 (IET Wiring Regulations) ensures safety and proper cable support .

Practical Tips

• Always secure brackets to solid structures like joists, battens, or walls to prevent loosening over time .
• For long horizontal runs, consider intermediate supports or rollers to reduce cable stress during installation .
• Ensure adequate clearance for maintenance, inspection, and airflow, especially in parallel or stacked tray installations . By assessing cable weight, tray type, and environmental conditions, installers can determine the optimal bracket spacing that balances safety, structural integrity, and cost efficiency .