LINETRAXX® VMD423/VMD423H

According to DIN V VDE V 0126-1-1, the voltage and frequency shall be monitored when feeding power into the public low voltage grid from private electricity generation systems > 30 kW (such as CHPs, wind power stations, hydroelectric power plants and photovoltaic systems).

The three-phase VMD423 series voltage and frequency monitors monitor the voltage and frequency at the feeding point of the public grid. At the feeding point of the medium voltage grid, the output voltages and frequencies are measured by means of voltage transformers (100 V). An alarm relay is activated within ≤ 80 ms when limit values are reached (response values according to VDEW guideline “Private electricity generation systems at the medium voltage grid”). An overvoltage (> U2), measured as average value over a 10-minute period, will cause the alarm relay to switch.

The voltages are measured as r.m.s. values. In addition asymmetry, phase failure and phase sequence are monitored. 

The VMD423 is suitable for multifunctional monitoring tasks and can be adapted to the requirements of the electricity supply companies.

The currently measured values are continuously shown on the LC display. The measured value causing the alarm relay to switch is saved. Due to adjustable start-up delay and delay on release, the network operator's specific requirements can be considered such as device-specific start-up procedures, short-time voltage fluctuations etc.

The VMD423 series requires a separate supply voltage, whereas the VMD423H version draws its supplies from the system.

Certificate of non objection in accordance with

• DIN V VDE V 0126-1-1:2006-02 (France, Switzerland)
• DIN V VDE V 0126-1-1:2006-02 and EN 50438:2007 (Czech Republic)
• C10/11 (Belgium)

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