The angle of a cable tray bend can be calculated using the tray width divided by a factor derived from the desired angle, or by using trigonometric relationships for offsets.

Basic Formula for Cut-Out Section

To create a specific bend angle in a cable tray, you can use the following method:

1. Determine the desired angle $B$ (in degrees) for the bend.
2. Calculate the factor $C$ by dividing 90° by the angle: $$C=\frac{90}{B}$$
3. Divide the cable tray width $A$ by $C$ to find the size of the cut-out section $D$: $$D=\frac{A}{C}$$

For example, for a 22° bend in a 600 mm wide tray:

This gives the length of the tray side to cut to achieve the desired angle .

Formula for Parallel Offsets

When creating a parallel offset to bypass an obstacle:

1. Determine the total offset distance $O$ and the straight-line distance $L$ over which the offset occurs.
2. Divide the straight-line distance by the tray width to get the number of sets: $$N=\frac{L}{A}$$
3. Divide the total offset by the number of sets to find the cut size per set: $$D=\frac{O}{N}$$

For example, a 350 mm offset over a 1500 mm run with a 600 mm tray:

This ensures a smooth transition without sharp bends .

Using Trigonometry for Sloped or Vertical Offsets

For vertical or sloped offsets, the angle $\theta$ can also be calculated using basic trigonometry:

This is useful for determining the slope of a tray section when bypassing obstacles or changing elevation .

Practical Considerations

• Bend angles: Common angles are 15°, 22.5°, 30°, 45°, and 60°, chosen based on cable bending radius and available space .
• Tray width: Always measure the actual tray width for accurate cut calculations.
• Cable type: Heavier or high-voltage cables require gentler bends (smaller angles) to avoid damage.
• Installation space: Ensure sufficient horizontal and vertical clearance for smooth cable pulling. By applying these formulas, you can accurately calculate the cut size and angle for cable tray bends, offsets, and vertical transitions, ensuring safe and efficient cable routing.