Cable Tray Bend Calculator
Accurate cable tray bend calculations for electrical installations
Cable Tray Bend Calculator
Compliant with IEC 61537 Standards
Results:
Minimum Cable Bend Radius: -
Recommended Tray Bend Radius: -
How to Use the Calculator
1. Select Cable Type
Choose the specific cable category from the dropdown menu (e.g., Single Core, Multicore, Control, or MV/HV). This sets the correct Bending Factor (K).
2. Enter Cable Diameter
Input the overall outside diameter of the cable in millimeters (mm). Ensure this is the value from the cable datasheet.
3. Calculate & Review
Click "Calculate" to see the minimum bending radius and the recommended standard tray bend radius (300mm to 900mm) required for safe installation.
Engineering Notes
IEC 61537 / NEC 392 Standards
- Tray bend radius must be ≥ minimum cable bend radius.
- Use the largest cable diameter in the tray for calculation.
- Always select the next higher standard tray radius (300, 450, 600, 900 mm).
How to Calculate Cable Tray Bend
1. Identify Cable Data
Determine the cable type (e.g., Single Core, Multicore) and measure the overall outside diameter (OD). This is crucial for selecting the correct bending factor.
Diameter (D) = Cable OD in mm
2. Apply Bending Factor
Multiply the cable diameter by the standard multiplier (K) for your cable type. For example, use K=12 for single core and K=10 for multicore power cables.
Rmin = K × D
3. Select Standard Radius
Choose a cable tray fitting with a radius equal to or greater than your calculated minimum. Common standards are 300, 450, 600, and 900 mm.
Tray Radius ≥ Rmin
Cable Tray Bend Chart
| Cable Diameter (mm) | Multicore Power (10x) | Single Core Power (12x) | Control / Inst (8x) | MV / HV Power (15x) |
|---|---|---|---|---|
| 20 mm | 200 mm (Use 300) | 240 mm (Use 300) | 160 mm (Use 300) | 300 mm (Use 300) |
| 30 mm | 300 mm (Use 300) | 360 mm (Use 450) | 240 mm (Use 300) | 450 mm (Use 450) |
| 40 mm | 400 mm (Use 450) | 480 mm (Use 600) | 320 mm (Use 450) | 600 mm (Use 600) |
| 50 mm | 500 mm (Use 600) | 600 mm (Use 600) | 400 mm (Use 450) | 750 mm (Use 900) |
| 60 mm | 600 mm (Use 600) | 720 mm (Use 900) | 480 mm (Use 600) | 900 mm (Use 900) |
Cable Tray Bend FAQs
How to calculate cable tray bends?
Calculate the minimum required bend radius by multiplying the cable's outside diameter by its bending factor (e.g., 10x for multicore). Then, select a standard tray fitting (300mm, 450mm, etc.) that matches or exceeds this value.
How to calculate cable bending?
Use the formula R = K × D, where R is the radius, D is the cable diameter, and K is a multiplier based on cable type (typically 8x for control, 10x for multicore, and 12-15x for single core or HV cables).
How to 90 degree bend cable tray?
For a 90-degree bend, ensure the tray's internal radius meets the cable's minimum bend requirement. If fabricating, mark the side rail at intervals based on the calculated arc length, cut V-notches, and bend the tray until the gap closes.
How do you calculate bending?
Bending is calculated by determining the arc length needed for a specific angle. The formula is Arc Length = (2 × π × Radius × Angle) / 360. This length represents the curved portion of the tray.
How to calculate 30 degree offset?
For a 30-degree offset, the distance between bends (hypotenuse) is calculated as Offset Distance × Cosecant(30°), which equals Offset × 2. The total length of tray used increases slightly due to the angle.
How to do 45 in tray?
To create a 45-degree bend, cut the side rails to remove a segment calculated by the formula (Tan(22.5°) × Width). Alternatively, use a pre-fabricated 45-degree fitting with a radius sufficient for your largest cable.
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