Type 1 protectors against transient overvoltages should be tested with 10/350 µs lightning impulse wave, simulating the effects of direct lightning discharges.
Type 1+2 protectors against transient overvoltages should be tested with 10/350 µs lightning impulse wave and 8/20 µs wave, combining the capacity to absorb lightning current with low residual voltage.
Type 2 protectors against transient overvoltages should be tested with 8/20 µs current impulse wave, simulating lightning secondary effects.
Type 2+3 protectors against transient overvoltages should be tested with 8/20 µs current impulse wave and a combination impulse wave, leaving low residual voltages.
Type 3 protectors against transient overvoltages should be tested with a combination impulse wave, simulating very attenuated overvoltages.
