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Creepage and clearance measure distances of the shortest path between electrically conductive components. Creepage refers to the shortest distance along the surface of an insulator. Clearance measures that distance through the air. Creepage can also take short circuits into account for gaps and grooves across surfaces, where the air has less resistance.

The repercussions of violating minimum distances can be extremely expensive. (And, of course, anytime you are dealing with electricity, poor designs can cause injuries or worse.) If discovered too late, problems can result in a product recall, which damages your company’s reputation and market share. When discovered early, issues can be mitigated by modifying the harness routing or implementing a physical barrier between components.