Cable trays cannot generate tees

Cable trays do not automatically generate tee fittings because fittings must be explicitly created and oriented to connect segments properly, unlike straight runs.

Manual vs Programmatic Creation

When cable trays are created manually in software like Revit, the system automatically rotates segments and adds the appropriate fittings, including tees, elbows, and risers, to connect the trays seamlessly. However, when creating cable trays programmatically using APIs, such as CableTray.Create, the software only generates the straight tray segments without any fittings or automatic alignment between them. This is because the application must explicitly create each fitting and ensure correct orientation for proper connection .

Fitting Requirements

A tee fitting requires three connectors: one for the main run and two for the branch. Attempting to replace a tee with a single-connector branch piece will not work because the software cannot reconcile the missing connections. While some physical branch fittings exist in real life, they often require on-site modifications, such as cutting the main tray to fit the branch, which cannot be automatically modeled in software .

Solutions

1. Use Tee Fittings: Modify a tee fitting to visually mimic a branch if needed, ensuring all three connectors are present for proper modeling .
2. Create Separate Runs: Start a new unconnected tray run at the branch location and annotate any on-site modifications required.
3. Programmatic Approach: Use the API's New*Fitting methods to place elbows, tees, or other fittings between segments, making sure each segment is correctly aligned before creating the fitting .

Practical Considerations

Cable tray systems have rectangular cross-sections, making alignment more complex than round conduits. Proper orientation is essential for fittings to connect correctly, which is why automatic generation is not supported in most software. Manual intervention or explicit programming is required to ensure accurate modeling .