The Ex9UE3 line is a group of Class III Surge Protective Devices. They are intended as a fine protection against transient overvoltage, installed downstream to Class II SPDs. The application field of Ex9UE3 is protection of sensitive electronics used in or close to distribution board, typically home automation, IT systems etc. The Y connection of functional elements provides balanced protection of L and N conductor towards PE thanks to identical MOVs for both working conductors and full isolation due to connection to PE via Spark Gap.
Class III SPDs should be installed maximum 5 meters form the protected device. Coordination with Class II SPDs Ex9UE2 20 is defined also for near installation. To reach best parameters, it is recommended to install both classes with mutual distance of 5 meters of connecting cables.
The design of Ex9UE3 is based on Metal Oxide Varistors. Such design provides very low response time. The modular design with plug in inserts allows simple and quick replacement of function modules in case of MOV is beyond if its lifespan due to often occurrence of overvoltage peaks.