1.professional surge protector for ac power 2.working voltage: 220V /380V AC 3.1,2,3,4P(+NPE) 4.ISO9001 5.8 ... Level Power-supply Module (4P,3P+NPE) surge protector for ac power 1. Third level protection2. install in the frond of ... , do not affect the normal power supply. Technology Parameter:Model SY-B-20KA/4PSY-B-20KA/3P+NPENominal alternating voltageUn380V380VMaximum Discharging ...