Product informatie voor LINETRAXX® VMD421H

The multi-functional voltage relays of the VMD421H series are designed to monitor the frequency, undervoltage and overvoltage and the voltage between two threshold values (window discriminator function) in 3(N)AC systems. The voltages are measured as r.m.s. values. The currently measured value is continuously shown on the LC display. The measured value leading to the activation of the alarm relays will be stored. Due to adjustable response times, installation-specific characteristics, such as device-specific start-up procedures, short-time voltage fluctuations, etc. can be considered. Device version VMD421H takes the supply voltage from the system being monitored and utilizes an internal energy backup.