3.3.4.3 Probabilities of damage in case of direct lightning strikes into supply lines

The probability values P_U for injuries to living beings within the structure due to touch voltages caused by a direct lightning flash to a line that enters the structure depend on the shielding properties of the supply line, the impulse withstand voltage of the internal systems connected to the supply line, the protective measures (physical restrictions or warning notices) and any isolating interfaces or SPDs provided at the point of entry into the structure in accordance with IEC 62305-3 (Equation 3.3.4.3.1):

[equation](3.3.4.3.1)

P_am describes protective measures against touch voltages, such as physical restrictions and warning notices; the values in Table 3.3.4.1.1 apply again. If more than one protection measure is taken, the value of P_U is the product of the relevant values.