How to represent a reducing elbow in a cable tray

A reducing elbow in a cable tray is represented by a parametric elbow fitting that transitions between different tray widths while changing direction, and can be modeled in CAD or BIM software using automatic or manual insertion of reducers.

General Representation in CAD

In CAD programs like CADprofi, reducing elbows are treated as parametric fittings that can be drawn with specified dimensions. To represent a reducing elbow:

• Select the elbow fitting from the cable tray or duct library.
• Specify the elbow angle (e.g., 45°, 90°) and the direction of bend.
• Set the width transition to match the two connecting tray sizes. The software can automatically adjust the fitting to connect trays of different widths.
• Use the Diameter Fit or similar option to ensure the reducer adapts to the connected tray dimensions . This approach allows the reducing elbow to be accurately represented in both plan and cross-section views, maintaining proper alignment and scale.

Representation in Revit MEP

In Revit MEP, reducing elbows are handled through cable tray families:

• Load the appropriate cable tray fittings family into the project. For reducing elbows, ensure the family supports reducing width options .
• When connecting two trays of different widths, Revit can automatically place a reducer at the elbow if the family is set up correctly. This is typically achieved by using a Ladder Multi Port or similar part type in the family settings .
• Set the bend angle and side width options in the family parameters. Checking the “Reducing Width” option allows the front-to-back rail width to adjust automatically at the elbow . This method ensures that the reducing elbow is parametrically accurate and updates automatically if tray dimensions change.

Practical Tips

• Always verify that the fitting library includes reducing elbows for the tray type you are using (ladder, perforated, solid-bottom).
• In CAD, use copy dimensions or retrieve dimensions functions to match existing tray sizes when inserting elbows .
• In Revit, avoid creating custom families unnecessarily; use system families with built-in reducer functionality to simplify modeling .
• For documentation, represent the reducing elbow in plan, side, and cross-section views to clearly show the width transition and bend angle. By following these steps, a reducing elbow can be accurately represented in both CAD and BIM environments, ensuring proper design, coordination, and documentation of cable tray systems .