The thickness of a cable tray is chosen based on three factors: the weight of the cables per meter, the width of the tray, and the spacing between the supports. The greater the width, the heavier the cables, or the wider the spacing between the supports, the thicker the tray or the higher the sides. Thicknesses between approximately 1.0 and 2.5 mm are common in projects. The goal is for the tray to support its cables without visible sagging or permanent deformation throughout its lifespan.<\/p>\n
The tricycle acts as a small bridge between two supports. The cables compress it from above, causing it to bend in the middle. Resistance to this bending comes primarily from the sides (side edges), as these act as the load-bearing beam, while the base transfers the weight to them. Therefore:<\/p>\n
Therefore, you might find a 1.5mm thick tray with 100mm sides stronger than a 2.0mm thick tray with 50mm sides at the same distance. A proper comparison should be made between products of the same shape, or by consulting the load-bearing charts provided by the manufacturer.<\/p>\n
This is a crucial point often overlooked. In the structural calculations of a beam carrying a distributed load, the moment increases with the square of the span, and the deflection increases approximately with its fourth force. In practical terms: if you double the spacing between supports from 1.5 meters to 3 meters, the deflection in the middle not only doubles but becomes approximately 16 times greater, theoretically, for the same load.<\/p>\n
The result is that slightly closer spacing the supports may allow you to use less thickness, and it may be more economical than increasing the thickness along the entire path. Conversely, if the location doesn't allow for many supports (such as open walkways or crossings over internal roads), you'll need a stronger tread or a ladder-type tread designed for long spans. Details on spacing and installation methods are in the article. Cable tray installation and spacing between supports<\/a>.<\/p>\n Some specifications directly link load capacity to distance. For example, the American standard NEMA VE 1 classifies cable trays into categories that combine span length and load class per unit length, so you'll find a code in the catalog that specifies both the span and the load. The international standard IEC 61537 specifies a method for testing the safe working load of a tray over a given span. It's important to understand that the load rating is meaningless without specifying the distance between the supports over which it was tested.<\/p>\n The first step in choosing the thickness is to determine the actual load. Method:<\/p>\n Illustrative example (approximate figures):<\/strong> A route with 6 power cables, each weighing approximately 2.5 kg\/m, and 10 control cables, each weighing approximately 0.3 kg\/m. The load = (6 \u00d7 2.5) + (10 \u00d7 0.3) = 15 + 3 = 18 kg\/m. With the 25% expansion margin, it becomes approximately 22.5 kg\/m. With this figure and the spacing between supports, refer to the manufacturer's load-bearing table and select the size and thickness. Actual weights are taken from the catalog of the cable actually being used.<\/p>\n To quickly estimate size and list materials, use Cable Tray Calculator<\/a>It takes into account the fullness ratio and suggests the appropriate width and height.<\/p>\n The following table reflects common market practices for galvanized perforated trellis and is for guidance only. The final selection depends on the actual load, the spacing between supports, and the product's load-bearing capacity.<\/p>\nHow do international standards express durability?<\/h3>\n
How do you calculate the weight of cables per meter?<\/h2>\n
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Guideline table: Common widths and thicknesses<\/h2>\n