Adequate spacing prevents short circuits and enhances system safety: Bare copper busbars: Minimum clearance ≥20mm to avoid phase-to-phase or phase-to-ground faults. Insulated busbars: Insulation allows for reduced clearance but must meet IEC 60664or UL 746Cdielectric strength. When considering bus spacings, two dimensions are important. The first is clearance, or the distance through air between conductors of opposite polarity or between an energized conductor and ground. The distances are. Introduction: The National Electric Code (NEC) and other regulatory bodies have established guidelines for busbar clearances and spacings to ensure safe operation and prevent electrical shock. The clearances and spacings required depend on various factors, including the busbar current, voltage, and. Phase to phase clearance as per IEC 61439 is one of the core safety requirements in low-voltage switchgear and control gear assemblies. This standard ensures that electrical equipment operates safely under normal and abnormal conditions. Clearance values affect insulation, fault protection. a.