MODULE 5 — Over Voltages
5.1 Lightning & Switching Surges
$$ V = Z \cdot I $$
$$ V_T = V \frac{2 Z_2}{Z_1 + Z_2} \quad (\text{Transmitted
Surge}) $$
5.2 Surge Arresters
$$ I \propto V^\alpha $$
Where $\alpha$ (non-linearity exponent) is very
high for ZnO arresters.