VMD421HCH-D-3 Überwachungsrelais

The VMD421H multifunctional voltage relays monitor frequencies, undervoltages, overvoltages and the voltage between two threshold values (window function) in 3(N)AC systems. The voltages are measured as effective values. The current measured value is permanently shown on the LC display. The measured value leading to the switching of the alarm relays is stored. Adjustable delay times allow system-specific characteristics to be taken into account, e.g. device-related start-up phases, short-term voltage changes, etc. The VMD421H version takes the supply voltage from the system to be monitored and has an internal energy store.

Main features:

- Monitoring of undervoltage, overvoltage and frequency in 3(N)AC systems 0...500 V

- Integrated energy storage

- Monitoring of asymmetry, phase failure, phase sequence

- Start-up, response and release delay adjustable

- Various monitoring functions selectable < U, > U, < f, > f

Features and functions:

- Monitoring of undervoltage, overvoltage and frequency in 3(N)AC systems 70...500/288 V

- Without separate supply voltage

- Integrated energy storage

- Monitoring of asymmetry, phase failure, phase sequence

- Various monitoring functions selectable

- < U, > U, < f / > f

- Start-up, response and release delay

- Adjustable switching hysteresis

- Effective value measurement (AC)

- Digital measured value display via multifunctional LC display

- Preset function (automatic basic parameterization)

- LEDs for operation, alarm 1, alarm 2

- Measured value memory for trigger value

- Permanent self-monitoring

- Internal test/reset button

- Two separate alarm relays, 1 changeover contact each

- Quiescent/operating current and fault memory behavior selectable

- Password protection for device settings

- Sealable transparent cover

- 2-module housing (36 mm)

- Spring terminal (two terminals per connection)

- RoHS-compliant

Technical features:

- For 3(N)AC systems

- With frequency monitoring, phase sequence,

- phase failure, asymmetry

- 2 changeover contacts

- Display range: 70 ...500V AC

- Mains voltage: 15 ...460 Hz / 70 ...500 V AC

- The device does not require a separate supply voltage

- Weight: 240g

- Dimensions W36 x H90 x D110 mm

Applications:

- Monitoring of voltage-sensitive machines and systems

- Switching systems on and off above a certain voltage

- Monitoring of emergency or backup power supplies

- Monitoring the supply voltage of mobile consumers

- Protection of three-phase motors against phase failure and phase reversal

- Protection of transformers by detecting asymmetrical loads

Installation position:

According to the technical device manual: Vertical, see dimensional drawing