LINETRAXX® VMD421H

Undervoltage, overvoltage and frequency monitoring in 3(N)AC systems 0…500 V
Integrated energy backup
Asymmetry, phase failure and phase sequence monitoring
Adjustable start-up delay, response delay and delay on release
Various monitoring functions selectable < U, > U, < f, > f

The multi-functional VMD421 series voltage relay is 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 required to trigger the alarm relay is stored. Due to adjustable response times, installationspecific characteristics, such as device-specific start-up procedures, short-time voltage fluctuations, etc. can be considered. The devices are supplied by the system being monitored and utilise an internal energy backup.

Questions? Contact us!

Undervoltage, overvoltage and frequency monitoring in 3(N)AC systems 0…500 V
Integrated energy backup
Asymmetry, phase failure and phase sequence monitoring
Adjustable start-up delay, response delay and delay on release
Various monitoring functions selectable < U, > U, < f, > f

The multi-functional VMD421 series voltage relay is 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 required to trigger the alarm relay is stored. Due to adjustable response times, installationspecific characteristics, such as device-specific start-up procedures, short-time voltage fluctuations, etc. can be considered. The devices are supplied by the system being monitored and utilise an internal energy backup.

Questions? Contact us!

Features

Undervoltage, overvoltage and frequency monitoring in 3(N)AC systems 70…500/288 V
Without external supply voltage
Integrated energy backup
Asymmetry, phase failure and phase sequence monitoring
Various monitoring functions selectable < U, > U, < f, > f
Start-up delay, response delay, 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

Applications

Monitoring of voltage-sensitive machines and electrical installations
Switching machinery and equipment on and off at a certain voltage level
Monitoring of stand-by and emergency supply systems
Supply voltage monitoring of portable loads
Protection of three-phase motors against phase failure and phase open-circuit
Transformer protection, asymmetrical load can be recognised