... 1.For TN-S,TN-C-S,TT,IT etc. Power supply system 2.1.2.3.4P(+NPE) 3.IEC61643-1 ... .For TN-S,TN-C-S,TT,IT etc. Power supply system2.1.2.3.4P(+NPE)3.IEC61643-1 ... from the network, meanwhile send an indication signal. The visible window show white color in normal service, if to be separated ... NPE neutral and earthing protection modules, used in the power supply system of TN-S,TN-C-S and etc.Technical parameter ...