LYD5 OBO type surge protective device Amp:20-40KA, 10-20KA Pole:1P, ... , TN-S, TN-C-S etc. power supply system of AC 50/60HZ, installed on the joint of LPZ1 or LPZ2 ... . When SPD fails in breakdown for over-heat and over-current, the failure release will help electric device separate from the ... , punctual delivery time.6. Best service after sale are provided. AC OBO type surge protective device