Specifications of Tubular Busbars

Tubular busbars are hollow conductors, typically made of aluminium or copper, designed for high-current transmission in substations and power systems, with standard current ratings of 1250 A or 2000 A.Material and ConstructionTubular busbars are generally manufactured from high-purity aluminium or aluminium alloys (e.g., 6061, 6063) for new installations, while copper is used for extensions to existing copper systems . The hollow tubular design optimizes weight, mechanical strength, and heat dissipation, making them more efficient than solid rods for AC systems due to the skin effect . Aluminium busbars are lightweight, corrosion-resistant, and cost-effective compared to copper .Dimensions and Cross-SectionTypical tubular busbars feature a round hollow tube structure. Example dimensions include a diameter of 120 mm with a wall thickness of 10 mm, providing a high cross-sectional area for low resistance and efficient current flow . The tubular geometry maximizes surface area, improving heat dissipation and reducing temperature rise during operation.Current RatingsAccording to ENA TS 41-11 standards, aluminium tubular busbars are supplied with continuous current ratings of 1250 A or 2000 A . The number of clamps and fittings is determined by the current rating, ensuring safe and reliable connections . Copper extensions follow ENA TS 41-16 specifications.Fittings and ConnectionsFittings for tubular busbars include joints, clamps, and conductor fittings designed to avoid deformation of the tube and ensure proper electrical contact . All terminal fittings employ current-carrying half clamps, with two clamps on fixed fittings for mechanical stability. Special precautions are taken for copper-to-aluminium connections to prevent electrochemical corrosion .ApplicationsTubular busbars are widely used in:Outdoor primary substations up to 132 kV High-current circuits such as generator busbars, transformer bus systems, and large switching equipment Renewable energy projects and industrial facilities requiring lightweight, high-capacity conductors Space-constrained installations, where tubular geometry allows easier wiring and reduced support structure costs AdvantagesHigh current-carrying capacity with efficient AC performanceLightweight and cost-effective compared to copperExcellent heat dissipation due to hollow designMechanical strength and rigidity for substation environmentsCompliance with international standards (BS EN 61936-1, ENA TS 41-11/16) for safety and reliability Tubular busbars provide a robust, efficient, and economical solution for high-current electrical distribution, combining mechanical durability with optimized electrical performance.