Harmony Control. This network monitoring relay monitors three-phase networks for phase sequence, phase failure, phase asymmetry (5-15%), overvoltage and undervoltage in window mode (2-20%). A relay changer is available for reporting, which can be loaded up to 5 A. In the event of a phase error, the output drops out without delay; in the event of asymmetry and voltage errors, a switch-off delay can be set. The settings are made using control elements on the front, which can be protected against changes under a transparent cover. Two LEDs show the status. The width is 17.5 mm and it is mounted on the top hat rail. Supply from the measuring circuit 208-480 VAC (50-60 Hz).