Standard Requirements for Tubular Busbar Connections

Tubular busbar connections require precise material selection, proper fittings, correct torque application, and adherence to international standards to ensure safe and reliable electrical performance.Material and Conductor RequirementsTubular busbars are typically manufactured from aluminum for new installations and copper for extensions to existing systems, unless a break in the system allows aluminum to be used for continuity . The conductor material must be compatible with the fittings and terminals to prevent electro-chemical corrosion, especially in aluminum-to-copper connections . The busbar must also meet current-carrying capacity and thermal stability requirements, considering both steady-state and short-circuit conditions .Fittings and ClampsAll fittings for tubular busbars should employ current-carrying half clamps, with the number of clamps determined by the current rating of the fitting. Fixed fittings always require at least two clamps for mechanical stability . Fittings must be designed to avoid deformation of the tube conductor and minimize the risk of incorrect assembly. Special tools may be required to ensure proper installation and alignment.Mechanical and Installation ConsiderationsStraightness and surface quality: Busbars must be straight and free from cracks, pits, or surface defects before processing. Sections with defects exceeding allowable limits should be removed .Bending: Busbars should be bent carefully to avoid cracking, with consistent bending degrees for parallel busbars of the same phase. Minimum bending radii must be respected, and no cracks should appear after bending .Torque application: Electrical current concentrates under the pressure washers of bolted joints, so proper torque is critical to reduce contact resistance and ensure reliable current flow . Overlapping area alone does not improve conductivity.Insulation and SupportBusbars may require insulation layers to provide electrical barriers, reduce inductance, and improve thermal performance. Common materials include Nomex®, Mylar®, Kapton®, and epoxy-glass composites . Support insulators and structures must be designed to withstand short-circuit forces, wind loading, and mechanical stresses as specified in BS EN 61936-1 .Standards ComplianceTubular busbar connections must comply with national and international standards, including:ENA TS 41-11 for aluminum systems and ENA TS 41-16 for copper systems IEC 62271-301 for performance validation of busbar joints BS EN 61936-1 for high-voltage power installations Relevant GB standards (GB5584-85 for aluminum, GB55852-85 for copper) for Chinese applications Summary of Best PracticesSelect compatible materials and fittings to prevent corrosion.Ensure busbars are straight, defect-free, and properly bent.Use the correct number of clamps and apply proper torque.Follow insulation and support requirements to maintain electrical and mechanical integrity.Validate performance according to international and national standards rather than relying solely on geometric assumptions. Following these requirements ensures safe, efficient, and long-lasting tubular busbar connections in substations and switchgear installations.