Phase monitor for monitoring the normal mains supply
DNÜ is a phase monitor, which is used to monitor the normal mains supply.
The DNÜ is connected to a LPS/CPS system by means of a 24 V mains monitoring loop. As soon as one of the normal mains supply phases to be monitored falls below the nominal voltage by more than 15 %, the phase monitor opens the mains monitoring loop. The LPS/CPS system now switches on the emergency lighting off the area concerned and supplies the luminaires via the mains (local emergency mode).