1. Introduction
The LiebeWH DVRD-48 DC Voltage Monitor Relay is designed to protect DC systems from both overvoltage and undervoltage conditions. This device monitors the DC voltage in real-time and activates its contacts when the voltage exceeds or falls below user-defined thresholds. It is suitable for a wide range of applications, including DC motors, battery systems, UPS power supplies, DC switchgear, DC panels, and industrial control systems.
2. Safety Information
Please read and understand all safety instructions before installing or operating this device. Failure to follow these instructions may result in electric shock, fire, or serious injury.
- Ensure all power is disconnected before installation or maintenance.
- Installation should be performed by qualified personnel only.
- Verify correct wiring connections according to the provided diagram.
- Do not exceed the specified voltage and current ratings.
- Keep the device away from moisture and extreme temperatures.
3. Product Overview
The DVRD-48 DC Voltage Monitor Relay features a compact design for 35mm DIN rail mounting. It includes adjustable settings for overvoltage and undervoltage thresholds, as well as an adjustable action delay time. Two LED indicator lamps provide visual feedback on the device's operational status. The relay provides two sets of normally open (NO) and normally closed (NC) contacts for versatile control applications.
Image 3.1: Multi-feature overview of the DC Voltage Monitor Relay, showing its standard modular structure, real-time monitoring capability, adjustable settings, and no need for an auxiliary power supply.
4. Specifications
| Feature | Specification |
|---|---|
| Protection Function | Overvoltage and Undervoltage |
| Model | DVRD-12/24/36/48 (This unit is DC 48V) |
| Rated Voltage | DC 12V/24V/36V/48V (Specific unit: DC 48V) |
| Monitoring Circuit | DC circuit |
| Overvoltage Adjustment Range (DC 48V) | 52-68V |
| Undervoltage Adjustment Range (DC 48V) | 40-56V |
| Action Delay Range | 0.1-15 seconds |
| Display Mode | Normal, 2 LED indicators |
| Contact Form | Two sets of normally open and normally closed contacts |
| Contact Capacity | 6A 250VAC (resistive) |
| Installation | 35mm Guide Rail |
| Overall Dimensions | Approx. 79 × 23 × 79 mm / 3.1 × 0.9 × 3.1 inches |
| Weight | Approx. 109g / 7.1oz |
| Manufacturer Part Number | LiebeWHcv1gyfbz862565-04 |
| ASIN | B09L55YDFJ |
Image 4.1: Dimensions of the LiebeWH DVRD-48 DC Voltage Monitor Relay, showing approximate measurements of 79mm x 23mm x 79mm.
Image 4.2: Close-up of the product label, detailing the model DVRD-48, rated voltage 48VDC, overvoltage range 52-68VDC, undervoltage range 40-56VDC, and contact current 6A/250VAC.
5. Setup and Installation
The DVRD-48 relay is designed for easy installation on a standard 35mm DIN rail. Follow these steps for proper setup:
- Mounting: Securely attach the relay to a 35mm DIN rail in your electrical enclosure.
- Wiring: Refer to the wiring diagram printed on the side of the device for correct connections. Connect the DC power source to the input terminals. Connect the load or control circuit to the relay's output contacts (NO, COM, NC) as required by your application.
- Power On: Once all connections are secure and verified, apply DC power to the device.
Image 5.1: Rear view of the relay, illustrating the clips for 35mm DIN rail mounting.
6. Operating Instructions
The DVRD-48 allows for adjustment of voltage thresholds and action delay. Use a small screwdriver to carefully adjust the potentiometers on the front panel.
Image 6.1: Front panel of the relay, showing the adjustment dials for overvoltage (U>), undervoltage (U<), and time delay (Tt), along with the two indicator lamps.
- Overvoltage Threshold (U>): Rotate the 'U>' dial to set the desired overvoltage protection limit. When the monitored DC voltage exceeds this value, the relay will activate after the set delay.
- Undervoltage Threshold (U<): Rotate the 'U<' dial to set the desired undervoltage protection limit. When the monitored DC voltage falls below this value, the relay will activate after the set delay.
- Action Delay (Tt): Rotate the 'Tt' dial to set the time delay (0.1-15 seconds) before the relay contacts change state after a voltage fault is detected. This prevents nuisance tripping from momentary voltage fluctuations.
- Indicator Lamps: Two LED lamps indicate the working status of the device. Refer to the device's label for specific lamp indications (e.g., normal operation, fault condition).
Note: The manufacturer states that new and old types of this product may be shipped randomly. While functionality remains consistent, minor aesthetic differences might be present. Please ensure this is acceptable before ordering.
Image 6.2: A visual comparison between the new and old models of the DC Voltage Monitor Relay, highlighting potential minor variations.
7. Applications
The LiebeWH DVRD-48 DC Voltage Monitor Relay is versatile and can be integrated into various DC power systems for protection and control. Common applications include:
- DC Motor Protection
- Battery System Monitoring
- UPS Power Supply Protection
- DC Switchgear Control
- DC Panel Integration
- Industrial Control Systems
Image 7.1: Examples of wide applications for the DC Voltage Monitor Relay, including air conditioning units, elevators, refrigerators, water pumps, charging stations, and electric motors.
8. Maintenance
The DVRD-48 DC Voltage Monitor Relay is designed for reliable operation with minimal maintenance. However, periodic checks can help ensure its longevity and proper function.
- Cleaning: Keep the device clean and free from dust and debris. Use a soft, dry cloth for cleaning. Do not use liquid cleaners.
- Connections: Periodically inspect all wiring connections to ensure they are tight and free from corrosion.
- Environmental Conditions: Ensure the operating environment remains within the specified temperature and humidity ranges.
9. Troubleshooting
If you encounter issues with your DVRD-48 DC Voltage Monitor Relay, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Device not powering on | No input voltage; incorrect wiring; faulty device. | Check DC power supply; verify wiring according to diagram; contact support if device is faulty. |
| Relay trips unexpectedly | Voltage fluctuations; incorrect threshold settings; faulty sensor. | Adjust 'Tt' (delay time) to a longer duration; verify 'U>' and 'U<' settings; check input voltage stability. |
| Relay does not trip during fault | Incorrect threshold settings; faulty relay contacts; voltage within normal range. | Verify 'U>' and 'U<' settings are appropriate for your system; test relay contacts; confirm actual voltage levels. |
| LED indicators not working | No power; faulty LEDs. | Check power supply; if power is present and device functions, LEDs may be faulty (contact support). |
