1. Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of the MEAN WELL DR-120-12 AC-DC DIN Rail Power Supply. Please read this manual thoroughly before using the product and retain it for future reference.
2. Safety Instructions
WARNING: Risk of electric shock. Installation and servicing should only be performed by qualified personnel.
- Ensure the power supply is disconnected from the main voltage before any installation or maintenance work.
- Protect against accidental contact with live parts.
- Ensure proper grounding (earth connection) is established.
- Do not operate the unit in environments with high humidity or extreme temperatures outside the specified range.
- Do not open the casing; there are no user-serviceable parts inside.
- Observe all local and national electrical codes and regulations.
3. Product Overview
The MEAN WELL DR-120-12 is a 120W single output industrial DIN rail power supply, providing a stable 12V DC output at up to 10A. It features universal AC input and is designed for installation on standard DIN rails, making it suitable for various industrial control applications.
Figure 3.1: Front view of the MEAN WELL DR-120-12 AC-DC DIN Rail Power Supply, showing input/output terminals and specifications label.
Figure 3.2: Close-up of the top terminals (+V, -V, DC OK) and ventilation grille on the MEAN WELL DR-120-12, indicating output connections and cooling features.
4. Specifications
| Parameter | Value |
|---|---|
| Model | DR-120-12 |
| Output Voltage | 12V DC |
| Output Current | 10A |
| Output Power | 120W |
| Input Voltage Range | 88-132VAC / 176-264VAC (selectable by switch) |
| Frequency Range | 47-63Hz |
| Efficiency | Typically 85% |
| Mounting Type | DIN Rail (TS-35/7.5 or TS-35/15) |
| Operating Temperature | -20°C to +70°C (refer to derating curve) |
| Dimensions (L x W x H) | 125 x 100 x 70 mm (approximate, refer to dimension drawing) |
| Certifications | CE, UL Listed |
Figure 4.1: Technical drawing illustrating the dimensions of the DR-120-12 power supply in millimeters.
5. Installation and Setup
5.1 DIN Rail Mounting
The DR-120-12 is designed for easy installation on standard TS-35/7.5 or TS-35/15 DIN rails. Ensure the unit is mounted vertically to allow for proper heat dissipation through convection cooling.
- Hook the top edge of the power supply onto the DIN rail.
- Push the bottom edge firmly until it clicks into place.
- Verify that the unit is securely fastened to the DIN rail.
Figure 5.1: Example of the DR-120-12 power supply securely mounted on a DIN rail, demonstrating the proper installation method.
5.2 Wiring Connections
Before making any connections, ensure the AC input voltage selector switch (115VAC/230VAC) on the front panel is set correctly according to your local mains voltage. Incorrect setting can damage the unit.
- Input Terminals (Bottom): Connect the AC mains supply to the L (Line), N (Neutral), and ⌂ (Ground) terminals. Use appropriate wire gauges for the current rating.
- Output Terminals (Top): Connect your load to the +V and -V terminals. Observe polarity. The "DC OK" LED will illuminate when the output voltage is within tolerance.
- Voltage Adjustment: A potentiometer (ADJ) is located on the front panel for fine-tuning the output voltage within a small range.
Figure 5.2: Overview of the DR-120 series, highlighting the input (bottom) and output (top) terminal blocks for wiring connections.
6. Operation
Once properly installed and wired, apply AC power to the input terminals. The "DC OK" LED indicator on the front panel will light up, indicating that the output voltage is present and within its specified range. The unit is now operational and supplying power to the connected load.
- Overload Protection: The unit features overload protection. If an overload occurs, the output voltage may drop or shut down. Reduce the load to restore normal operation.
- Overvoltage Protection: If the output voltage exceeds a preset limit, the unit will shut down to protect the connected equipment. Power cycling may be required to reset.
7. Maintenance
The DR-120-12 power supply is designed for reliable operation and requires minimal maintenance. Regular inspection is recommended to ensure optimal performance and safety.
- Cleaning: Keep the ventilation openings clear of dust and debris to ensure proper airflow. Use a soft, dry brush or compressed air for cleaning. Do not use liquid cleaners.
- Inspection: Periodically check all wiring connections for tightness and signs of wear or damage. Ensure the unit is securely mounted.
- Environmental Conditions: Ensure the operating environment remains within the specified temperature and humidity ranges.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No output voltage / "DC OK" LED off | No AC input power Incorrect input voltage switch setting Overload or short circuit on output Internal fault | Check AC mains supply and connections. Verify 115VAC/230VAC switch setting. Disconnect load, check for short circuits, reduce load. Contact support if problem persists. |
| Output voltage too low | Overload condition Voltage adjustment (ADJ) set too low | Reduce load. Adjust ADJ potentiometer clockwise to increase voltage. |
| Unit is hot to touch | Insufficient ventilation Overload condition High ambient temperature | Ensure proper clearance around the unit and clear ventilation openings. Reduce load. Ensure ambient temperature is within specifications. |
If troubleshooting steps do not resolve the issue, contact qualified service personnel or the manufacturer for assistance.
9. Warranty and Support
MEAN WELL products are typically covered by a manufacturer's warranty. For specific warranty terms and conditions, please refer to the documentation provided with your purchase or visit the official MEAN WELL website. For technical support or service inquiries, please contact your distributor or the manufacturer directly, providing the model number (DR-120-12) and serial number of your unit.
10. Disposal Information
This product contains electronic components and should not be disposed of with general household waste. Please dispose of this product in accordance with local regulations for electronic waste recycling. Proper disposal helps prevent potential negative consequences for the environment and human health.
