BENDER VMD421H-D-3 Voltage Monitoring Relay

BENDER VMD421H-D-3 | Voltage Monitoring Relay (3-Phase, Multifunctional)

Specifications

• System Voltage: 3(N)AC 70–500 V / 288 V
• Frequency Range: 15–460 Hz (10–500 Hz adjustable)
• Voltage Accuracy: ±1.5% (50/60 Hz); ±3% (15–460 Hz)
• Asymmetry: 5–30% (adjustable, default 30%)
• Hysteresis: 1–40% (default 5%)
• Supply: Self-powered from monitored system; integrated energy backup
• Relay Outputs: 2 × changeover contacts (250 V AC, 5 A)
• Display: LCD with backlight (true RMS measurement)
• Delays: Startup/Response/Release: 0–300 s (each adjustable)
• Operating Temp: -10°C ~ +55°C
• Mounting: DIN rail (36 mm width, 2-module)
• Weight: approx. 0.22 kg

Key Features

1. Multifunctional Monitoring: Overvoltage/Undervoltage, Overfrequency/Underfrequency, phase loss, asymmetry, phase sequence
2. True RMS Measurement: Accurate for AC+DC, harmonics, and distorted waveforms
3. Self-Powered: No external supply needed; works even with brief voltage dips
4. Preset Function: One-click setup for standard 400 V/50 Hz or 230 V/50 Hz systems
5. Data Logging: Stores trip values; event memory with time stamp; password protection

Applications

• 3-phase industrial systems, generators, UPS, and standby power
• Motor protection (phase loss/asymmetry prevention)
• Transformers, pumps, fans, and critical loads
• Medical, marine, and IT power systems