... Power-supply Module (4P,3P+NPE) surge protector for ac power 1. Third level protection2. install in ... residual voltage, quick response, standard guide rail design, standard plug-in modular design, easy installation, simple maintenance, module degradation indication ... affect the normal power supply. Technology Parameter:Model SY-B-20KA/4PSY-B-20KA/3P+NPENominal alternating voltageUn380V380VMaximum ...