The width of a cable tray for low-voltage busbars depends on the busbar size, number of bars, and spacing requirements, typically ranging from 100 mm to 600 mm or more for standard installations.

Key Considerations for Cable Tray Width

Busbar dimensions and spacing: Low-voltage busbars are sized according to current rating, short-circuit withstand, and thermal limits as per IEC 61439-6 and IEC 60287 standards . The width of the cable tray must accommodate the busbar width plus sufficient spacing for insulation, ventilation, and safe handling. Typical spacing between busbars ranges from 20 mm to 50 mm depending on voltage and current rating . Number of busbars: A single-phase or three-phase system will require different tray widths. For example, a three-phase low-voltage busbar system with copper bars rated for 1600 A may require a tray width of 300–400 mm to allow proper separation and airflow . Ventilation and heat dissipation: Busbars generate heat under load. Cable trays must provide adequate clearance above and around the busbars to prevent overheating. Standards recommend a minimum of 50 mm clearance above the busbar for natural convection, which influences the overall tray width . Mechanical support and safety: The tray must support the weight of the busbars and any covers or protective enclosures. Lateral finger-safe covers and inlay supports are often included, which add to the required tray width . Typical widths: Based on manufacturer catalogs and technical guides, low-voltage busbar cable trays commonly come in widths such as 100 mm, 150 mm, 200 mm, 300 mm, 400 mm, and 600 mm, with custom widths available for higher current ratings or multiple busbar arrangements .

Summary

When selecting a cable tray for low-voltage busbars, consider:

• Busbar width and number of phases
• Required spacing for insulation and ventilation
• Heat dissipation and airflow
• Mechanical support and protective covers
• Compliance with IEC 61439-6 and local electrical codes By accounting for these factors, the tray width can be chosen to ensure safe, efficient, and code-compliant installation.