Cable tray size change

Cable tray size can be changed either by adjusting its physical dimensions based on cable load calculations or by modifying its size in design software like Autodesk Revit.

Modifying Cable Tray Size in Design Software

If you are using software such as Autodesk Revit, follow these steps to change the tray size:

1. Go to the Manage tab and open MEP Settings.
2. In the Electrical Settings dialog, expand Cable Tray Settings and select Size.
3. Choose the desired cable tray size and click Modify Size.
4. Enter the new dimensions in the Modify Cable Tray Size dialog and click OK to apply the changes . For bulk modifications, you can use filters to select multiple trays and apply the new size simultaneously, ensuring consistency across your project .

Calculating the Correct Physical Size

When changing the physical size of a cable tray, consider the following:

• Cable Count and Type: Determine the number and type of cables (power, data, control) to calculate the required cross-sectional area .
• Width and Depth: Standard widths range from 50mm to 900mm, and depths from 50mm to 150mm. The width is based on the number of cables laid side-by-side, while depth ensures proper stacking and heat dissipation .
• Fill Ratio: Only fill the tray to about 40% of its capacity to allow airflow and prevent overheating .
• Future Expansion: Consider potential future cable additions to avoid frequent resizing or replacement .
• Material and Load Capacity: Ensure the tray material and thickness can support the total cable weight and comply with standards like NEMA or NEC .

Practical Tips

• Always verify installation space (ceiling height, wall clearance) before resizing.
• For angled or vertical runs, you may need custom tray heights or additional supports.
• Use manufacturer specifications to confirm maximum load and heat dissipation limits.
• Document changes in your project plans to maintain compliance and facilitate maintenance. By combining software modification and proper physical sizing calculations, you can efficiently adjust cable tray dimensions to meet both current and future project requirements.