... 1P,2P,3P,4P Low voltage power surge arrester protection 1. Description: surge protection device (SPD, surge protector, surge arrester) is suitable for TT, IT, ... TN-S, TN-C-S etc. power supply system of AC 50/60HZ, installed ... , GB18802. It adopts 35mm standard rail. When SPD fails in breakdown for over-heat and over-current, the failure release ...