Well generally circuit breakers dont trip when lightening strikes. Lightening arrestors are there to protect the the equipments and transmission lines from lightening. Just in case if it fails the circuit breaker can trips due to excess voltage. read more
When lightning strikes a line, it induces a voltage spike. Traditional circuit breakers are current-sensing devices (whether solid state or electromechanical). So, a temporary spike in voltage (V) will, for a fixed resistance (R), create a temporary spike in current (I). If the spike is big enough, it trips the circuit breaker. read more
An Earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations with high Earth impedance to prevent shock. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected. read more