90 degrees inside the cable tray

A 90-degree inside bend in a cable tray can be achieved using either fabricated mitered bends or prefabricated elbow fittings, depending on the tray type and installation requirements.

Fabricated 90° Bends

For metal cable trays, a fabricated or mitered bend involves cutting and bending a straight tray section to form a 90° angle. The typical method uses two 45-degree cuts on the tray sides, followed by removing V-shaped sections from the base to allow the sides to close together. The tray is then fastened with bolts and nuts, and cold galvanizing spray can be applied for rust protection. Tools required include an angle grinder or hacksaw, measuring tape, set square, drill, and fastening hardware .

Prefabricated Elbow Fittings

Many manufacturers offer prefabricated 90° inside elbows for both vertical and horizontal changes in direction. These fittings are designed for smooth cable pulling and structural support:

• Vertical Inside Elbows: These allow a plane change in the cable tray, typically available in standard radii such as 12", 24", or 36". They are compatible with various NEMA classes and include splice plates for secure attachment .
• Fiberglass Elbows: Fiberglass inside vertical elbows come factory-drilled and compact, providing smooth cable routing and easy installation .
• Adjustable Elbows: Some elbow joints can be pushed inside the tray and secured with screws, allowing a range of -90° to +90° for flexible orientation changes .

Installation Considerations

• Ensure the bend radius is sufficient to prevent cable damage and maintain bend limits specified by cable manufacturers.
• Use appropriate fasteners and splice plates to maintain structural integrity.
• For vertical bends, verify that the elbow supports the weight of the cables and complies with the tray's NEMA class.
• For fabricated bends, precise measurement and cutting are critical to ensure a clean 90° turn without gaps or misalignment. By choosing the right method—fabricated or prefabricated—installers can achieve a smooth, structurally sound 90-degree inside bend that maintains cable integrity and system reliability.