... surge protective device Amp:20-40KA, 10-20KA Pole:1P,2P,3P,4P Low voltage power surge protective device 1. Description ... , TN-S, TN-C-S etc. power supply system of AC 50/60HZ, installed on the joint of LPZ1 or LPZ2 ... , punctual delivery time.6. Best service after sale are provided. AC OBO type surge protective device