The Influence Of Cable Terminal Metal Edge Shape On Creepage Distance

In the design of cable lugs, the distance between wire lugs and the terminal block must have sufficient creepage distance, which is referred to as creepage distance in standards such as IEC. The closer the conductive portions along the surface of the insulating material are, the higher the likelihood of current crossing the insulating surface.

Considering that the edge of electrical lugs is not rounded, it may form tiny sharp protrusions. This feature, under conditions of moisture, contamination, or dust accumulation, alters the surface electric field distribution, shortening the "surface creepage path" between high-voltage areas and adjacent conductors, increasing the likelihood of current migration along the insulating surface.