What is Let-through Voltage?, SPD, 낙뢰보호기, 서지보호기

What is Let-through Voltage?

Let-through voltage is the voltage appearing on the equipment side of an SPD when an impulse voltage/current of
a defined wave-shape and amplitude is applied to the SPD.

So, Let-through Voltage is a measure of the SPD’s ability to clamp a transient voltage.