... power surge protective device 1. Description: surge protection device (SPD, surge protector, surge arrester) is suitable for TT, IT, TN-S, TN-C-S ... GB18802. It adopts 35mm standard rail. When SPD fails in breakdown for over-heat and over- ... current, the failure release will help electric device separate from the power system and give indication ... sale are provided. AC OBO type surge protective device