Harmony Control. This voltage monitoring relay monitors a measuring circuit for exceedance of the set limit value (15-500 VAC/DC). Two relay changeovers are available for reporting, which can be loaded up to 8 A. The limit value and the switching hysteresis are adjustable. The settings are made using control elements on the front, which can be protected against changes under a transparent cover. An illuminated scale arrow makes it very easy to see the setting of the potentiometers, even from a distance. The diagnostic switch on the front enables the output relays to be switched off to test the entire application. When the transparent cover is closed, the diagnostic switch is automatically reset. The wide-voltage power supply (24-240 VAC/DC) enables universal use. Two LEDs show the status. The overall width is 22.5 mm and it is mounted on a top hat rail. The cable connection is made using screw terminals.