BENDER LINETRAXX ® VMD420 Three phase Voltage Frequency Monitor

BENDER LINETRAXX ®  VMD420 Three phase Voltage Frequency Monitor

Product Overview

LINETRAXX ®  VMD420 is a multifunctional voltage frequency monitor launched by BENDER, designed specifically for 3 (N) AC systems. Its core is used to monitor voltage (under voltage, over voltage), frequency (under frequency, over frequency), and phase related parameters (phase sequence, phase loss, asymmetry). The measurement voltage range covers 0... 500 V (L-L)/0... 288 V (L-N), and the frequency range is 15... 460 Hz. It adopts true RMS (AC+DC) measurement method to ensure data accuracy. The product complies with CE, DIN EN 45545-2, and IEC series standards, with high reliability and industrial grade protection performance, suitable for various electrical safety monitoring scenarios.

Core functions and features

（1） Comprehensive monitoring function

Voltage monitoring: It can simultaneously achieve undervoltage (U<) and overvoltage (U>) monitoring, with a monitoring range of AC 6... 500 V (3AC system, L-L wiring) or AC 6... 288 V (3 (N) AC system, L-N wiring), with a voltage setting resolution of 1 V, which can meet high-precision monitoring requirements. The device has a built-in preset function that automatically configures response values for different rated voltage systems: in the 3AC system, when the rated voltage Un is 400 V, the undervoltage preset value is 340 V (0.85Un) and the overvoltage preset value is 440 V (1.1Un); In the 3 (N) AC system, when Un is 230 V, the preset undervoltage value is 196 V and the preset overvoltage value is 253 V, without the need for manual configuration.

Frequency monitoring: Supports under frequency (<f) and over frequency (>f) monitoring, with a frequency setting range of 10... 500 Hz, where the resolution of the 10.0... 99.9 Hz interval is 0.1 Hz and the resolution of the 100... 500 Hz interval is 1 Hz, ensuring accurate capture of frequency fluctuations. The preset function is also applicable to frequency monitoring, with corresponding underfrequency and overfrequency preset values configured for rated frequencies of 16.7 Hz, 50 Hz, 60 Hz, and 400 Hz (such as 50 Hz corresponding to underfrequency of 49 Hz and overfrequency of 51 Hz), suitable for different power supply scenarios.

Phase related monitoring: including phase sequence, phase loss, and voltage asymmetry monitoring. Phase sequence monitoring supports recognition of two rotation directions: clockwise and counterclockwise. It is set to off by default and can be turned on according to actual system requirements; Phase loss is indirectly identified through voltage asymmetry threshold. When the three-phase voltage asymmetry exceeds the set value, an alarm is triggered; The asymmetric monitoring range is 5... 30%, and the factory defaults to 30%. It can be adjusted according to the system load characteristics to effectively prevent equipment damage caused by three-phase imbalance.

Measurement accuracy: The relative error of voltage measurement at 50/60 Hz power frequency is only ± 1.5% (± 2 digits), and the relative error within a wide frequency range of 15... 460 Hz is ± 3% (± 2 digits); The relative error of frequency measurement within the range of 15... 460 Hz is only ± 0.2% (± 1 digit), and high-precision measurement ensures the accuracy of alarm triggering, avoiding false alarms or missed alarms.

（2） Flexible time parameter configuration

Start delay (t): Set the range to 0... 300 seconds, with the factory default of 0 seconds. This function can avoid false alarms caused by unstable voltage and frequency during the device's power on start-up phase, and adapt to electrical characteristic fluctuations during the device's start-up process.

Response delay (ton1/2): Adjustable for two alarm channels, with a range of 0... 300 seconds and a default of 0 seconds. The delay time can be set according to the short-term fluctuations in on-site voltage and frequency, filtering out instantaneous interference signals and ensuring the reliability of alarm triggering.

Release delay (toff): Set the range from 0 to 300 seconds, with a default of 0.5 seconds. When the monitoring parameters return to the normal range (response value ± hysteresis), the device will not immediately reset, but will switch back to the initial state after a release delay to prevent frequent relay actions caused by repeated parameter fluctuations.

Action and recovery speed: The action time of voltage signal is ≤ 140 ms, and the action time of frequency signal is ≤ 335 ms, with rapid response and the ability to capture faults and trigger protection in a timely manner; The equipment recovery time is ≤ 300 ms, and after troubleshooting, it can quickly restore normal monitoring status.

（3） Display and storage functions

Display module: equipped with a multifunctional non luminous LC display screen, which can display the current measured voltage and frequency values in real time (display range 0... 500 V), and can also display device setting parameters, alarm status and other information. The interface is simple and intuitive, making it easy to view on site.

Storage function: equipped with running value memory function, which can record key parameters of the device during normal operation; Historical Memory (HiS) can store the measurement values at the first alarm, providing data support for troubleshooting; Fault memory supports three modes: on, off, and on. It is enabled by default. When set to continuous mode, even if the power supply is interrupted, the alarm parameters will still be retained, and historical fault information can be viewed after power supply is restored.