a) conventional assumed withstand voltage, when the number of disruptive
discharges tolerated is zero. It is deemed to correspond to a withstand probability
b) statistical withstand voltage, when the number of disruptive discharges tolerated
is related to a specified withstand probability. In this Standard the specified probability
P, = 1 O0 O ! ;
is P, = 90 O/O.
NOTE - In this Standard, for non-self-restoring insulation are specified conventional assumed withstand
voltages, and for self-restoring insulation are specified statistical withstand voltages.