This standard applies to normally open surge protectors with integrated spark gap overcurrent protection function (hereinafter referred to as SIS). The SIS may be connected to circuits and equipment with a rated AC voltage not exceeding 440 V rms, 50/60 Hz. SIS refers to an electrical appliance that contains non-linear components used to limit voltage and discharge surge current, and is combined with over-current protection functions. It has the function of protecting indirect lightning and direct lightning effects or other transient overvoltage surges, and has the ability to interrupt the system fault power frequency current generated by short-circuit failure of its internal nonlinear components. SISs with AC rated voltage not exceeding 1000 V (effective value) may refer to this standard.
T/CEEIA 390-2019 history
2019T/CEEIA 390-2019 SPDs with integrated overcurrent protection function based on spark gap