VMD421H-D-3 BENDER Input module

Description

VMD421H-D-3 BENDER Input module

Product Dimensions：

Product Description

The VMD421H-D-3 is a sophisticated digital monitoring relay that evaluates the voltage and frequency of three-phase systems. It is characterized by its high flexibility and precision, offering separate adjustable response values for various fault conditions. The device is designed to detect “asymmetry” (phase imbalance) and phase failure, and it features a backlit LC display that shows real-time measured values. Its “H” designation typically indicates a specific auxiliary voltage range or high-performance characteristic, while the “D-3” denotes its digital design optimized for three-phase applications.

Product Parameters

Product Advantages

• High Precision: Digital measurement technology ensures accurate monitoring of RMS values, reducing the risk of false trips or missed faults.

• Versatile Monitoring: Combines voltage (over/under), frequency (over/under), phase sequence, and phase asymmetry monitoring into a single compact unit.

• Real-Time Visualization: The integrated display allows operators to see current system status immediately without needing external meters.

• Adjustable Time Delays: Features programmable start-up delays and response delays, which prevent nuisance tripping caused by temporary voltage sags or motor starts.

• Password Protection: Settings can be locked to prevent unauthorized changes to the safety parameters.

Important Considerations

• Phase Rotation: Ensure the phase sequence is correctly wired if phase rotation monitoring is enabled, as the device will trip if it detects an incorrect sequence.

• Neutral Connection: Depending on the system configuration (3AC vs 3N AC), ensure the neutral conductor is connected if phase-to-neutral monitoring is required.

• Environment: While durable, the device should be mounted in a clean, dry enclosure to maintain its IP30 (housing) and IP20 (terminals) ratings.

• Fused Protection: It is highly recommended to protect the voltage sensing inputs with appropriate fuses to prevent damage during extreme surges.

Product Applications

• Renewable Energy: Monitoring the grid connection points for solar or wind power plants to ensure they meet utility requirements for voltage and frequency stability.

• Industrial Automation: Protecting sensitive three-phase machinery, such as CNC machines and high-precision pumps, from damage caused by phase loss or voltage spikes.

• Emergency Power Systems: Monitoring the quality of power from backup generators before transferring critical loads.

• HVAC Systems: Preventing motor burnout in large industrial compressors due to phase imbalance or undervoltage conditions.

Shipping Port: Xiamen, China

Payment: Bank of Chicago, Bank of Singapore

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