|Definition:|| peak value of an impulse test voltage at which insulation at the work location exhibits, under specified conditions, a referenced value of probability of withstand|
Note 1 to entry: The purpose is to reduce the risk of breakdown of the insulation to an acceptably low level. It is generally considered that an acceptable low level is reached when the value of the required insulation level is greater than or equal to the overvoltage which has a probability of being exceeded by no more than 2 %.
Note 2 to entry: This entry was numbered 651-01-17 in IEC 60050-651:1999. It has been modified as follows: Editorial, to take into consideration the changes being made to IEC 60050-604.