... S,TT,IT etc. Power supply system 2.1.2.3.4P(+NPE) 3.IEC61643-1 Standard power surge protectors1.For TN-S ... ,TT,IT etc. Power supply system2.1.2.3.4P(+NPE)3.IEC61643-1 StandardSPD have only one side terminal, ... earthing protection modules, used in the power supply system of TN-S,TN-C-S and etc.Technical ... 450Voltage protection level Up(KV) Less than0.8/1.51.8/2.0Max.discharging current(8/20 us) (KA) ...