How to install grounding for tubular busbars

Tubular busbars should be grounded using secure mechanical or exothermic connections, with proper spacing and mounting to ensure electrical continuity, mechanical stability, and compliance with standards.

Connection Techniques

Tubular busbars can be grounded using either mechanical lugs or exothermic (Cadweld) connections. Mechanical lugs are fastened directly to the busbar, providing a reliable path for current, while exothermic welding creates a permanent, low-resistance bond that is highly durable and corrosion-resistant (nVent ERICO). For high-current applications, exothermic connections are preferred due to their superior conductivity and long-term stability.

Mounting and Fixing Spacing

Proper mounting spacing is critical for tubular busbars to prevent sagging, deformation, and excessive thermal expansion. Typical fixing spacing ranges from 300mm to 600mm, depending on busbar size, weight, and environmental conditions (e.g., vibration, temperature fluctuations). Larger or heavier busbars require closer spacing to maintain mechanical integrity, while areas with strong vibrations or seismic activity benefit from tighter mounting to prevent fatigue fractures.

Grounding Layout

A common earthing point should be established for multiple panels or devices, ensuring all busbars are bonded to a single reference ground. This can be achieved using a perimeter busbar system or dedicated grounding bars, which allow for easy field installation and inspection. In sensitive environments, such as data centers or MRI rooms, closer spacing and precise alignment help maintain low resistance and reduce electromagnetic interference.

Installation Best Practices

Surface preparation: Remove oxidation and apply an antioxidant to ensure low-resistance connections. Use of compatible hardware: Select lugs, connectors, and insulators that match the busbar dimensions and material. Color-coded guides can simplify selection and installation.

Permanent bonding: Consider irreversible connectors or exothermic welds for critical grounding points to ensure long-term reliability. Inspection and maintenance: Regularly check for loose fasteners, corrosion, or misalignment to prevent system failure.

Standards Compliance

Ensure grounding methods comply with ANSI/TIA-607-B, NEC, and BICSI recommendations for bonding and grounding. This ensures safety, electromagnetic compatibility, and proper fault current dissipation. By following these methods—secure connections, proper spacing, common earthing points, and adherence to standards—tubular busbars can provide a reliable and safe grounding system for industrial, commercial, and sensitive electrical installations.