1. Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of the MEAN WELL MDR-40-24 DIN Rail Power Supply. Please read this manual thoroughly before using the product and retain it for future reference.
The MDR-40-24 is a 40W single output industrial DIN rail power supply, designed for installation on TS-35/7.5 or TS-35/15 standard DIN rails. It provides a stable 24V DC output with a current rating of 1.74A.
2. Safety Instructions
WARNING: Risk of electric shock and fire. Installation must be performed by qualified personnel only.
- Ensure the power supply is disconnected from the main AC input before any installation, wiring, or maintenance work.
- Do not operate the unit in environments with high humidity, extreme temperatures, or corrosive substances.
- Verify that the input voltage range (90-264V AC) matches your local power supply.
- Ensure proper grounding to prevent electric shock.
- Do not open the casing of the power supply. There are no user-serviceable parts inside.
- Maintain adequate ventilation around the unit to prevent overheating.
- Use conductors rated for at least 75°C.
- Terminal torque for connections should be 5 Lb-in.
3. Product Overview
The MEAN WELL MDR-40-24 is a compact and efficient power supply designed for industrial control applications. Key features include:
- Universal AC input / Full range (90-264V AC)
- Protections: Short circuit / Overload / Over voltage / Over temperature
- Cooling by free air convection
- Can be installed on DIN rail TS-35/7.5 or 15
- LED indicator for power on
- DC OK relay contact
Figure 3.1: Front view of the MDR-40-24 power supply, highlighting the input and output terminals, along with the product label detailing specifications and certifications.
Figure 3.2: Angled front view of the MDR-40-24, providing a clearer look at the terminal connections and the voltage adjustment potentiometer.
Figure 3.3: Rear view of the MDR-40-24, illustrating the built-in clip mechanism for secure attachment to a DIN rail.
Figure 3.4: Top-down angled view of the MDR-40-24, highlighting the ventilation slots designed for passive cooling.
4. Setup and Installation
4.1 Mounting
- Ensure the main power is OFF before mounting.
- Mount the MDR-40-24 onto a standard TS-35/7.5 or TS-35/15 DIN rail.
- Ensure sufficient clearance (at least 10mm on top and bottom, 5mm on sides) for proper ventilation.
- The unit should be mounted vertically to allow for optimal heat dissipation through convection.
4.2 Wiring Connections
Refer to the markings on the unit for correct terminal connections. Use appropriate wire gauges for the current rating.
- Input Terminals (AC):
- L: Live AC input
- N: Neutral AC input
: Protective Earth Ground
- Output Terminals (DC):
- +V: Positive DC output (24V)
- -V: Negative DC output (0V / Ground)
- DC OK Relay Contact:
- Provides a signal indicating the DC output status. Refer to the product datasheet for detailed relay specifications.
Note: Ensure all connections are secure and tightened to the specified torque of 5 Lb-in to prevent loose connections and potential hazards.
5. Operating Instructions
5.1 Power On
- After completing all wiring connections, switch on the main AC power supply.
- The "DC OK" LED indicator on the front panel should illuminate, indicating normal operation.
5.2 Output Voltage Adjustment
The MDR-40-24 features a potentiometer labeled "+V ADJ" on the front panel for fine-tuning the output voltage.
- Using a small screwdriver, carefully turn the potentiometer clockwise to increase the output voltage or counter-clockwise to decrease it.
- Monitor the output voltage with a multimeter to ensure it is within the desired range and does not exceed the maximum safe operating voltage for your connected devices.
Caution: Do not adjust the output voltage beyond the recommended range specified in the product datasheet to avoid damaging the power supply or connected equipment.
6. Maintenance
The MEAN WELL MDR-40-24 is designed for reliable operation and requires minimal maintenance.
- Cleaning: Periodically clean the exterior of the unit with a soft, dry cloth. Do not use liquid cleaners or solvents. Ensure the unit is powered off and disconnected before cleaning.
- Ventilation: Ensure that the ventilation openings are not obstructed by dust or debris. Clear any blockages to maintain proper airflow.
- Inspection: Regularly inspect wiring connections for tightness and signs of wear or damage.
- No User Serviceable Parts: Do not attempt to open or repair the unit. Refer all servicing to qualified service personnel.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No DC output / DC OK LED off |
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| Output voltage too low/high |
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| Unit is overheating |
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8. Specifications
| Parameter | Value |
|---|---|
| Model | MDR-40-24 |
| Brand | MEAN WELL |
| AC Input Voltage Range | 90-264V AC |
| Output Voltage | 24V DC |
| Output Current | 1.74A |
| Rated Power | 40W |
| Dimensions (WxDxH) | 40 x 90 x 100 mm |
| Mounting Type | DIN Rail (TS-35/7.5 or 15) |
| Minimum Frequency | 50 Hz |
| Current Rating | 1.74 Amps |
| Specification Met | CE |
| Item Weight | 0.01 Ounces (approx. 0.28 grams) |
9. Warranty and Support
For warranty information and technical support, please contact your authorized MEAN WELL distributor or visit the official MEAN WELL website. Keep your purchase receipt for warranty claims.
MEAN WELL provides product documentation and support resources online. For the most up-to-date information, refer to the official product datasheet and user manuals available on the manufacturer's website.