What is the difference between surge current and fault current with regard to a surge protector?
Surge Current: A protectors surge current rating depicts the protectors capacity to divert currents that are the result of momentary overvoltages caused by lightning or utility switching. A protectors peak current (Ipk) rating is usually based on the industry standard 8 x 20 microsecond waveform, which is a pulse that mimics lightning currents on a power line. This parameter is often used to describe the size of a protector. It is also used to recommend a protector for a particular location in a power system. For example, a branch panel may require an 80kA/Phase protector. This means that an 80kA/Phase protector is the right size protector for that particular location in the electrical system. Although you would be hard pressed to witness an 80kA surge in a branch panel location the higher surge current rating translates into longer protector life. You would not want to use a 10kA rated protector in an area that has repeated 10kA surges as the protector will only survive one event. The
