A 90-degree flat-angle elbow on a cable tray is typically fabricated by combining two 45-degree bends, carefully cut, bent, and fastened to maintain structural integrity and proper cable routing.

Tools and Materials Needed

• Straight cable tray section
• Cutting tools (angle grinder with cutting disc or hacksaw)
• Measuring tape, marker, set square, or protractor
• Drill and drill bits
• Nuts, bolts, and washers for fastening
• Cold galvanizing spray for rust protection (if steel trays)

Fabrication Steps

1. Mark the Center Line: Determine the desired bend location and draw a straight line across the tray base to serve as a reference for cuts .
2. Mark 45-Degree Cuts: Measure equal distances on both sides of the center line, typically 45–82 mm depending on tray width, and mark the flanges for cutting .
3. Cut the Side Channels: Cut the tray flanges at the 45-degree angles, stopping at the base.
4. V-Notch the Base: Remove V-shaped sections from the tray base to allow the sides to close together when bent .
5. Form the Elbow: Bend the tray along the notched lines to create two 45-degree bends, which together form a 90-degree elbow .
6. Fasten the Sections: Align the bent sections and secure them with bolts, nuts, and washers. Ensure the joint is tight and stable.
7. Protect the Metal: Apply cold galvanizing spray to exposed metal to prevent corrosion .

Design Considerations

• Segment Count: A 90-degree elbow typically requires three segments in real-world fabrication, while a 45-degree elbow uses two segments .
• Measurements: For precise bending, the base of the isosceles triangles cut from the tray can be calculated using the formula: L = 2 × (tray height × sin 22.5°), ensuring proper alignment and angle .
• Support and Load: Ensure the elbow is supported according to tray specifications, with maximum support spacing and load capacity considered .

Best Practices

• Always follow local electrical codes and safety standards.
• Verify measurements before cutting to avoid material waste.
• Use proper personal protective equipment (PPE) during cutting and bending.
• Consider pre-fabricated elbows if available to save time and ensure uniformity. By following these steps and considerations, a 90-degree flat-angle elbow can be safely and accurately installed on a cable tray system, maintaining both structural integrity and proper cable routing.