To calculate a right-angle bend in a cable tray, measure the tray width, determine the centerline radius, and use the cut-out formula to ensure proper bend radius and cable fill.

Step 1: Measure Tray and Cable Parameters

• Tray width (A): Measure the internal width of the tray where the bend will occur.
• Cable diameter: Use the finished outer diameter of the cables, not just the conductor size.
• Tray type: Ladder trays allow more space for cables, while solid-bottom trays restrict space and heat dissipation .

Step 2: Determine the Bend Radius

• Measure the centerline radius of the bend, not the edge, to account for cable crowding on the inside of the bend .
• Ensure the radius meets the minimum bend radius for the cable type (e.g., Cat6A UTP requires at least 1.04 in for ladder trays ).

Step 3: Calculate the Cut-Out Size

For a pre-determined right-angle (90°) bend:

1. Divide 90° by the desired bend angle (B). For a single 90° bend, B = 90°, so C = 90 ÷ 90 = 1.
2. Divide the tray width (A) by C to find the cut-out size (D). For example, a 600 mm tray: D = 600 ÷ 1 = 600 mm . This cut-out allows the tray to bend without compressing cables excessively.

Step 4: Check Bend Fill and Clearance

• Calculate usable bend fill: the inner side of the bend is compressed, and the outer side is stretched. Ensure the total cable fill does not exceed safe limits .
• Leave side clearance for edge protection and future cable additions.

Step 5: Consider Offsets if Needed

• If the bend must avoid obstacles, calculate parallel offsets using the formula: divide the offset distance by the number of sets along the tray, then divide by tray width to determine each cut size .
• For complex routing, use trigonometry or a cable tray offset calculator to determine horizontal and vertical runs .

Step 6: Verify and Adjust

• Use a cable tray bend calculator to simulate the bend, check radius margin, bend take-up, and fill utilization before installation .
• Adjust the bend radius or cut-out size if the inner rail is too crowded or the bend is too tight. By following these steps, you can ensure a right-angle cable tray bend that maintains proper cable spacing, avoids exceeding bend-radius limits, and allows for future cable additions.