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  • Multi-functional monitoring relay for overvoltage, undervoltage, overfrequency, and underfrequency
  • Works on single-phase AC and DC systems up to 300 V
  • Digital display with real-time reading
  • Multiple time delays available (on startup, on trigger, on reset)
  • Two Form-C (SPDT) alarm contacts, configurable to trigger on any combination of alarms

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 currently measured value is continuously shown on the LC display. The measured value required to trigger the alarm relay is stored. Due to adjustable response times, installation-specific characteristics, such as device-specific start-up procedures, short-time voltage fluctuations, etc. can be considered. The relays require an external supply voltage.


  • Monitoring AC/DC systems for undervoltage, overvoltage and frequency in the voltage range of 0…300 V
  • Various monitoring functions selectable < U, > U, < f, > f
  • Start-up delay, response delay and delay on release
  • Adjustable switching hysteresis
  • r.m.s. value measurement (AC+DC)
  • Digital measured value display via multi-functional LC display
  • Preset function (automatic setting of basic parameters)
  • LEDs: Power On, Alarm 1, Alarm 2
  • Measured value memory for operating value
  • Continuous self monitoring
  • Internal test/reset button
  • Two separate alarm relays (one changeover contact each)
  • N/C or N/O operation and fault memory behaviour selectable
  • Password protection for device setting
  • Sealable transparent cover
  • Two-module enclosure (36 mm)
  • Push-wire terminal (two terminals per connection)
  • RoHS compliant


  • 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

Downloads for LINETRAXX® VME420

CE Declarations of Conformity VMx42x 93.7 KB 2022/11/04 09:31:2004.11.2022 09:31:20
Manuals VME420 1.8 MB EN2021/09/22 09:54:5022.09.2021 09:54:50D00026
Datasheets VME420 363.8 KB EN2022/08/10 05:51:4410.08.2022 05:51:44D00026
Quickstarts VME420 814.5 KB EN2021/09/22 09:55:0722.09.2021 09:55:07D00026
Datasheets XM420 interface options 223.5 KB EN2019/05/13 10:31:3613.05.2019 10:31:36D00051
Technical Information Changed variants of relays from goldplated to silver-plated contacts 166.3 KB EN2022/06/27 09:03:0827.06.2022 09:03:08

Optional Accessories for LINETRAXX® VME420

TypeArt No.
Mounting clip for screw fixing (1 piece per device)B98060008

LINETRAXX® VME420 Variants

TypeSupply voltage US*Nominal system voltage Un*Art. No.**
VME420-D-1DC 9,6 V…94 V / AC 16…72 V, 15…460 HzAC/DC 0…300 V / 15…460 HzB73010001
VME420-D-2DC 70…300 V / AC 70…300 V, 15…460 HzAC/DC 0…300 V / 15…460 HzB73010002

* absolute values
**(B7… = push-wire terminal / B9… = screw-type terminal)