2 Do horizontal and vertical trays need to be different sizes? Cable trays vary in size in order to accommodate varying numbers of wires. International projects are most often made in widths of between 50mm and 900mm and depths of between 50mm and 150mm. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned in this technical guide only apply to our own cable management ranges and cannot under any circumstances be transposed to si osure, overheating or. Selecting the right cable tray size is critical for electrical safety, system efficiency, and cost control. This comprehensive guide covers standard cable tray sizes, calculation methods, and practical selection tips—with real engineering examples.