Calculate the correct cable tray or trunking size with BS 7671 space factor compliance, cable segregation warnings, and support spacing recommendations. Add Cables This calculator is provided for informational and educational. Cable tray (or cable ladder) systems are a popular alternative to electrical conduit systems, as they have an outstanding record for dependable service, design flexibility and cost savings in commercial and industrial applications. A properly designed and installed cable tray system will provide. us-trations without notice. All illustrations, descriptions and technical information included in this document are provided as indications and can cable trays are equivalent. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. In practice, cable tray dimensions are a system of interrelated measurements —width, depth, length, and material thickness—that directly affect cable fill compliance, heat dissipation, structural loading, and long-term expandability. From an engineering standpoint, cable tray dimensions are not. maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. IEC 61537 and IEC 60364 require evaluating tray dimensions based on cable quantity, type, and layout configuration.