1Standard modular construction, rail mounted, no additional auxiliary power required. 2The overvoltage and undervoltage value is independently adjustable and the action time is adjustable. 32 sets of normally open normally closed contacts, 5 indicators indicate various working conditions. 4Overvoltage, undervoltage, phase error, phase loss, voltage imbalance and other protection functions, zero line disconnection fault monitoring function. 5Used in electric motors, fans, water pumps, air compressors, cranes, driving, lifts, elevators, machine tools, central air conditioners, refrigeration equipment, industrial control systems, etc.