Tubular Busbar Fixing Method

Tubular busbars must be securely fixed using appropriate clamps, support insulators, and fittings to ensure mechanical stability, electrical performance, and allowance for thermal expansion.

Busbar Materials and Fittings

New tubular busbar installations are typically made from aluminium tubes, while extensions to existing copper systems should match the original material unless a break allows for aluminium use . All fittings, including joints, clamps, and conductor connections, must be designed to avoid deforming the tube and ensure compatibility with the conductor and terminal equipment. Fixed fittings require two complete clamps for mechanical stability, while sliding fittings use clamps according to current rating . Special care is needed for copper-to-aluminium connections to prevent electrochemical corrosion .

Support Structures and Insulators

Busbars are mounted on support insulators and structures that account for short-circuit forces, wind loading, and thermal expansion . Supports should allow longitudinal movement to accommodate thermal expansion, preventing bending moments that could damage the busbar or insulators . Some designs use U-shaped clamping brackets with sliding mechanisms, allowing the busbar to move slightly while remaining securely clamped .

Jointing and Mechanical Fixing

Busbar sections are joined using bolted joints, where overlapping bars are secured with bolts and washers to ensure uniform pressure and low electrical resistance . Proper torqueing and alignment are critical to maintain both mechanical strength and electrical conductivity. For T-shaped or complex connections, specialized fittings may be used to maintain stability and performance .

Installation and Maintenance Practices

During installation, ensure that busbars are aligned correctly, clamps are tightened to specification, and all connections are free from contaminants . Regular maintenance includes visual inspections, cleaning, tightening bolts, and thermal imaging to detect hotspots or loose connections . This ensures operational safety, reduces energy losses, and extends the lifespan of the busbar system.

Practical Considerations

• Use special tools for assembly to minimize incorrect installation .
• Ensure sliding supports are free to move for thermal expansion .
• Follow manufacturer and standard specifications such as ENA TS 41-11 for aluminium and ENA TS 41-16 for copper systems .
• Observe electrical safety precautions during installation, especially in high-voltage environments . Proper fixing of tubular busbars ensures reliable power distribution, mechanical integrity, and long-term operational safety in substations and transformer assemblies.