Cable tray angle measurement

Cable tray angles are measured using the tray width and desired bend or offset, applying simple trigonometric calculations or industry-standard multipliers to determine cut sizes and placement.

Determining the Bend Angle

To measure or set a cable tray angle, first identify the desired bend or offset required to navigate obstacles or elevation changes. Common angles used in installations are 15°, 22.5°, 30°, 45°, and 60°, with 30° being the industry standard for balancing space efficiency and ease of cable pulling . Smaller angles like 15° or 22.5° are preferred for thick or high-voltage cables to maintain a smooth bend, while 45° or 60° are used in tighter spaces .

Calculating Cut Size for a Pre-Determined Angle

1. Measure the width of the cable tray (A).
2. Determine the angle you want to create (B).
3. Calculate the factor C by dividing 90° by the angle: C = 90° ÷ B.
4. Divide the tray width by C to find the cut-out size (D): D = A ÷ C. For example, for a 600mm tray with a 22° angle: C = 90 ÷ 22 ≈ 4.09 D = 600 ÷ 4.09 ≈ 147mm .

Calculating Parallel Offsets

When creating a parallel offset to bypass an obstacle:

1. Measure the total offset distance (e.g., 350mm) and the straight-line distance over which the offset occurs (e.g., 1500mm).
2. Divide the straight-line distance by the tray width: 1500 ÷ 600 = 2.5.
3. Divide the offset distance by this number: 350 ÷ 2.5 = 140mm. This gives the cut size for each bend to achieve a smooth offset .

Practical Tips

• Two bends per offset: Each offset requires two equal bends—one to move laterally and one to return to parallel .
• Use pre-fabricated fittings for standard angles (e.g., 45°) to save time and ensure consistency. Field bending is recommended for non-standard angles .
• Consider cable bending radius: Avoid sharp bends that could damage cables, especially for high-voltage or thick cables .
• Mark bending points along the straight tray before cutting to ensure accurate installation . By following these calculations and guidelines, you can accurately measure and set cable tray angles, ensuring safe, efficient, and compliant cable routing.