Cable tray parallel bend techniques

Parallel bending of cable trays involves bending multiple trays simultaneously while maintaining consistent spacing and alignment, typically using formulas or offset techniques to achieve precise angles.

Overview

Parallel bending is used when multiple cable trays run side by side and need to change direction without disrupting the spacing between them. This ensures that cables remain organized, supported, and free from mechanical stress. Proper bending also prevents damage to the tray and the cables it carries, maintaining compliance with standards such as BS EN 61537 for cable tray systems.

Techniques and Formulas

Offset Method: A common approach is to use an offset formula, such as the 1. 414 formula, to calculate the correct distances for bends at 45° or 90° angles. This ensures that each tray in the parallel run bends uniformly and maintains the same gap between trays.

Layered Bending: For multiple layers of trays, the same angle can be applied to each layer, with careful measurement of vertical and horizontal spacing to avoid interference. This is often demonstrated in practical guides and video tutorials showing 22. 5°, 45°, and 90° bends for three-line or multi-layer tray systems.

Gradual Bends: Using long-radius bends is recommended to reduce stress on cables. Ladder-type trays or tubular steel trays allow smooth, gradual curves, which are particularly important for high-density cable runs.

Best Practices

Support and Alignment: Ensure that all trays are properly supported with brackets or hangers before bending. Misalignment can cause mechanical stress and compromise cable integrity. Consistent Spacing: Maintain uniform spacing between trays to allow airflow, ease of maintenance, and prevent cable crowding.

Use of Fittings: Pre-fabricated bends, T-pieces, and crossovers can simplify parallel bending and reduce the need for on-site manual bending. Safety and Standards: Only trained personnel should perform bending operations, and all bends should comply with relevant electrical installation standards to ensure safety and durability.

Summary

Parallel bending of cable trays requires careful planning, precise measurement, and adherence to standards. Using formulas like the 1. 414 offset, gradual bends, and proper support ensures that multiple trays can be bent together without compromising cable integrity or system performance.