BENDER VME421H-D-1 Voltage Monitoring Relay

Description

BENDER VME421H-D-1 Voltage Monitoring Relay

Product Dimensions：

The Bender VME421H-D-1 is a high-precision digital voltage monitoring relay designed for single-phase and three-phase AC/DC systems. It is part of the VME421 series, specifically engineered to detect undervoltage, overvoltage, and window voltage conditions to protect sensitive electrical equipment.

Product Detailed Description

The VME421H-D-1 monitors the voltage between two thresholds (Min/Max). It features a built-in digital display for real-time monitoring and parameter configuration. The “H” in the model name typically indicates a higher functional range or specific auxiliary power requirements, and the “D-1” version is optimized for DIN rail mounting with specific delay timing capabilities.

Technical Parameters

Product Advantages

• High Versatility: A single unit can monitor both AC and DC systems, as well as 3-phase networks without a neutral conductor.
• True RMS Measurement: Provides accurate voltage readings even in harmonically distorted networks caused by VFDs or electronic loads.
• Precision Timing: Adjustable response and release delays prevent nuisance tripping caused by momentary voltage fluctuations or motor starting.
• Self-Monitoring: The device includes a permanent self-test feature; if an internal fault is detected, the alarm relays will signal a system error.
• Password Protection: Settings can be locked to prevent unauthorized personnel from changing safety thresholds.

Important Considerations (Precautions)

• Auxiliary Power: Ensure the auxiliary supply voltage (U_s) matches the specifications (100–240V). Operating outside this range may damage the internal electronics.
• Wiring Topology: When monitoring 3-phase systems without a neutral, ensure the parameters are correctly set in the menu to “3AC” to avoid false phase-failure alarms.
• Contact Rating: Do not exceed the maximum switching capacity of the output relays (typically 5A/250VAC). Use intermediate contactors for high-power loads.
• Environment: Avoid installing the unit in areas with high electromagnetic interference (EMI) without proper shielding, as it may affect the measurement accuracy.

Product Applications

The VME421H-D-1 is used where voltage stability is critical for operational safety:

• Control Cabinets: Protecting PLCs, HMIs, and sensitive electronics from brownouts or overvoltage spikes.
• Renewable Energy: Monitoring the output voltage of inverters in solar or wind power systems before grid connection.
• Mechanical Engineering: Protecting 3-phase motors from overheating due to phase imbalance or undervoltage.
• Infrastructure: Monitoring emergency power supplies (UPS) and standby generators in hospitals or data centers.

Shipping Port: Xiamen, China

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