Undervoltage monitoring in three-phase networks (each phase against neutral) with a fixed threshold, fixed hysteresis and integrated test button. It was specially developed for emergency lighting systems in accordance with DIN0108. The device can also be used to monitor a single phase. All unused inputs must be connected to the connected phase. If there is a reverse voltage caused by the consumer that is greater than the set threshold, no error message is issued. Good message: Relay is energized (contacts 11-14 and 21-24 closed), LED is off. Fault message: Relay is de-energized (contacts 11-14 and 21-24 open), LED is on. Press a button: Relay drops back (contacts 11-14 and 21-24 open), LED comes on. Operating voltage 3N 400/230 V, 50 Hz Tolerance -30 % to +10 % Consumption 16 VA (1.7 W) Recovery time less than 300 ms Drop-out voltage less than 85 % Trigger delay approx. 100 ms Threshold value 195 V AC, fixed Hysteresis approx. 5 %, fixed Output / contact 2 changeover contacts (DPDT), potential-free Output / switching voltage max. 250 V AC/DC Mechanical life 2 x 107 switching cycles Electrical life 2 x 105 switching cycles Display LED red, green Dimensions W x H x D 35 x 69.3 x 60 mm Weight 110 g Operating temperature range -5 °C to +55 °C Storage temperature range -20 °C to +70 °C Protection class housing / terminals IP40 / IP20