These distances are influenced by voltage level, pollution degree, and the system insulation category. The IEC 61439-1 standard is the most commonly used document for defining these values. It applies to low-voltage switchgear and control gear assemblies and provides a table of. Proper planning of safety distances in low-voltage busbar design and installation is critical for ensuring electrical performance, operational stability, and equipment safety. That is why experienced panel builders treat electrical clearance, creepage distance, and busbar spacing and sizing as early design inputs rather than. Clearance - the distance between two conductive parts along a string stretched the shortest way between these conductive parts. – Busbars, main & distribution.