1. Introduction
This manual provides essential information for the safe and efficient operation of your Meanwell NDR-120-48 Power Supply. This slim and economical 120W power supply delivers a stable 48V DC output at 2.5A, designed for industrial control equipment and various applications requiring reliable DC power. It features universal AC input, comprehensive protection mechanisms, and passive cooling for enhanced durability.
Figure 1: Meanwell NDR-120-48 Power Supply unit.
2. Setup and Installation
2.1 DIN Rail Installation
The NDR-120-48 is designed for easy installation on a standard DIN rail (TS35 / 7.5 or 15). To install, align the power supply's DIN rail clip with the rail and press firmly until it clicks into place. To remove, pull down the release lever on the clip and lift the unit off the rail.
Video 1: Demonstration of DIN rail installation for a power supply. This video illustrates the general method for mounting a power supply onto a DIN rail, which is applicable to the NDR-120-48 model.
2.2 Wiring Connections
Ensure all power is disconnected before making any connections. The unit features screw DIN terminals for both input and output connections. Strip the wire insulation, insert the wires into the appropriate terminals, and tighten the screws securely.
- AC Input: Connect the AC input (90~264VAC; 127~370VDC) to the terminals labeled 'N' (Neutral) and 'L' (Line). Ensure proper grounding to the 'PE' (Protective Earth) terminal.
- DC Output: Connect your device to the DC output terminals. The unit provides 48V DC. There are multiple positive (+) and negative (-) terminals for connecting multiple loads or for redundancy.
2.3 Output Voltage Adjustment
The NDR-120-48 includes a potentiometer for fine-tuning the output voltage. Use a small screwdriver to adjust the '+V ADJ' potentiometer to achieve the desired 48V output, or to compensate for minor voltage drops in long cable runs. Always verify the output voltage with a multimeter after adjustment.
3. Operating Instructions
3.1 Power-On and Status Indicator
Once properly wired and installed, apply AC power to the unit. The 'DC OK' LED indicator will illuminate green, signifying that the power supply is operating correctly and providing stable DC output. If the LED is off, refer to the Troubleshooting section.
3.2 Cooling
This power supply utilizes free air convection for cooling. Ensure adequate clearance (minimum 5mm left and right, 40mm above, and 20mm below) around the unit to allow for proper airflow and heat dissipation. Do not obstruct the ventilation holes.
4. Maintenance
The NDR-120-48 is designed for low maintenance. Due to its passive cooling design (no internal fan), there are no moving parts to wear out. Regular maintenance should include:
- Cleaning: Periodically inspect the unit for dust accumulation, especially around the ventilation holes. Clean with a soft, dry cloth or compressed air. Ensure power is disconnected before cleaning.
- Connection Check: Occasionally verify that all wiring connections are secure and free from corrosion.
- Environmental Check: Ensure the operating environment remains within the specified temperature and humidity ranges to prolong the lifespan of the unit.
5. Troubleshooting
- No DC Output / 'DC OK' LED Off:
- Check the AC input power supply.
- Verify all input and output wiring connections are correct and secure.
- Ensure the input voltage is within the specified range (90~264VAC).
- Check for short circuits or overloads on the DC output. The unit has overload protection and will auto-recover once the fault is cleared.
- If the unit has been exposed to high temperatures, it might be in over-temperature protection mode. Allow it to cool down and re-power.
- Incorrect DC Output Voltage:
- Use a multimeter to measure the output voltage.
- Adjust the '+V ADJ' potentiometer as described in Section 2.3.
6. Specifications
| Feature | Specification |
|---|---|
| Model Number | NDR-120-48 |
| Output Voltage | 48V |
| Output Current | 2.5 Amps |
| Approx. Wattage | 120W |
| AC Input Voltage Range | 90~264VAC; 127~370VDC |
| AC Inrush Current (max.) | Cold start, 35A at 230VAC |
| DC Adjustment Range | 48V: 48~55V |
| Overload Protection | 105%~130% Constant current limiting, auto-recovery |
| Over Voltage Protection | 48V: 56~65V |
| Over Temperature Protection | Shut down o/p voltage, re-power on to recover |
| Withstand Voltage | I/P-O/P: 3kVAC, I/P-FG: 2kVAC, O/P-FG: 0.5kVAC |
| Working Temperature | -20~+70°C (refer to output derating curve) |
| Safety Standards | UL60950-1, TUV EN60950-1 approved |
| EMC Standards | EN55022 class B, EN61000-3-2,3, EN61000-4-2,3,4,5,6,8,11, EN61000-6-2(EN50082-2), EN61204-3 |
| Connection | Screw DIN terminal (I/P: 3 poles, O/P: 4 poles) |
| Dimensions (LxWxH) | 40 x 125.2 x 113.5 mm (1.57 x 4.93 x 4.47 inches) |
| Item Weight | 1.43 pounds (0.65 Kilograms) |
7. Warranty
The Meanwell NDR-120-48 Power Supply comes with a 3-year warranty for the NDR series. Please retain your proof of purchase for warranty claims. For detailed warranty terms and conditions, refer to the manufacturer's official documentation or website.
8. Support
For technical assistance, product inquiries, or further support, please contact the manufacturer, Mean Well, or the brand, EverSale, through their official channels. You may also visit their respective websites for additional resources, FAQs, and contact information.
- Manufacturer: Mean Well
- Brand: EverSale
- Online Resources: Refer to the official Mean Well or EverSale websites for the latest product information and support.