Arc-Flash Calculator - Arc Gap

The distance between energized conductors or between energized conductors and ground. For 600 volts and below, arc gaps of 1.25 inches (32mm) were found to produce maximum incident energy in most cases. This is the default value used in the calculator. That distance is also typical of much low-voltage equipment. Smaller arc gaps result in less energy being expended in the arc, while longer gaps reduce arc current.