The common assumptions regarding lightning specifically, based ANSI/IEEE C62.41 and UL 1449 (3rd Edition) at time of this writing, are that minimum lightning-based power line surges inside a building are typically 10,000 amperes or 10 kiloamperes (kA). This is based on 20 kA striking a power line, the imparted current then traveling equally in both directions on the power line with the resulting 10 kA traveling into the building or home. These assumptions are based on an average approximation for testing minimum standards. While 10 kA is typically good enough for minimum protection against lightning strikes it is possible for a lightning strike to impart up to 200 kA to a power line with 100 kA traveling in each direction.