The VME420 series voltage relays are designed to monitor the frequency, undervoltage, overvoltage and the voltage between two threshold values in AC and DC systems. The voltages are measured as r.m.s. values. The measured value is continuously shown on the device’s front display. The measured value required to trigger the alarm relay is stored. Thanks to the VME’s adjustable response times, installation-specific characteristics, such as time delay start-up procedures, short-time voltage fluctuations, etc. can be configured to specific applications.
- Single-phase voltage and frequency monitoring of machines and electrical installations
- Earth fault monitoring in medium-voltage systems via voltage transformers
- Monitoring of battery systems
- Switching on and switching off at a certain voltage level