SPD category per IEC61643 (EN61643)
Class I SPD tests: Tests carried out with the impulse discharge current Iimp, with an 8/20 current impulse with a crest value equal to the crest value of Iimp, and with a 1,2/50 voltage impulse
Class II SPD tests: Tests carried out with the nominal discharge current In, and the 1,2/50 voltage impulse
Class III SPD tests: Tests carried out with the 1,2/50 voltage - 8/20 current combination wave generator
