MEAN WELL NDR-120-12 is a slim, metal-enclosed industrial DIN rail power supply rated at 12 V DC, 10 A and 120 W. Its 40 mm-wide housing supports compact control cabinets. It uses free-air convection and constant-current overload protection; observe the model-specific input and temperature derating conditions below.
Product Datasheet
Download MEAN WELL NDR-120 Datasheet (PDF)
The NDR-120 section is on PDF pages 5, 6, 7, 8. Refer to the complete mechanical drawings and notes when planning installation.
Model Identification
| Complete model |
NDR-120-12 |
| Series / voltage code |
NDR-120 is the slim industrial DIN rail family; the final 12 code denotes 12 V nominal DC output. Use the actual rated power below rather than the family number as an output guarantee. |
| Construction / intended use |
Metal enclosure with free-air convection, adjustable DC output and constant-current overload limiting. The catalogue lists industrial control, semiconductor fabrication, factory automation and electro-mechanical applications. |
DC Output
| Nominal output |
12 V DC; 10 A rated, current range 0–10 A; 120 W rated power. |
| Output-voltage adjustment |
12–14 V DC using +V ADJ. Stay within the permitted output current and power when adjusting. |
| Ripple and noise, maximum |
100 mVp-p. |
| Voltage tolerance |
±2.0%, including setup tolerance, line regulation and load regulation. |
| Line / load regulation |
±0.5% / ±1.0%. |
| Efficiency, typical |
85.5% under the stated default catalogue conditions. |
Ripple and noise are measured at 20 MHz bandwidth using a 12-inch twisted pair terminated with 0.1 µF and 47 µF parallel capacitors.
Input and Starting
| AC input / frequency |
90–264 VAC, full range; 47–63 Hz. Apply the low-input derating curve. |
| DC input and polarity |
127–370 VDC. Connect positive DC input to AC/L (+) and negative DC input to AC/N (-); maintain the FG protective-earth connection. |
| AC current, typical |
2.25 A at 115 VAC; 1.3 A at 230 VAC. |
| Inrush current, typical |
20 A at 115 VAC; 35 A at 230 VAC. |
| Setup / rise time |
1200 / 60 ms at 230 VAC; 2500 / 60 ms at 115 VAC, at full load. |
| Hold-up time, typical |
16 ms at 230 VAC; 10 ms at 115 VAC, at full load. |
| Leakage current |
Less than 1 mA at 240 VAC. |
Protection and Status Indication
| Short circuit / overload |
105–130% of rated output power. Constant-current limiting; automatic recovery after the fault condition is removed. This is a protection threshold, not an additional continuous or timed-peak output rating. |
| Overvoltage |
14–17 V; output shutdown, re-power to recover. |
| Overtemperature |
Output shutdown, re-power to recover. No numerical trip temperature is specified in this model’s table. |
| Status / adjustment |
The front drawing identifies a DC OK LED and +V ADJ. The LED is an indicator, not a separately specified DC OK relay contact. |
Cooling, Derating and Environment
| Operating range / orientation |
Free-air convection; -20 to +70°C with vertical mounting, subject to all derating curves. The temperature range does not mean full output is available throughout. |
| Low-temperature curve |
At 115 VAC, allowable load rises from 80% at -20°C to 100% at -10°C. The 230 VAC curve allows 100% in this low-temperature interval. |
| High-temperature curve |
At 115 VAC, this 12 V model remains at 100% through 45°C and then follows the lower curve to 50% at 70°C. At 230 VAC, it remains at 100% through 50°C and then follows the curve to 50% at 70°C. |
| Input-voltage curve, 60 Hz |
90% load at 90 VAC, rising to 100% at 100 VAC; the 100% plateau continues through 264 VAC. |
| Working humidity / storage |
Working: 20–95% RH, non-condensing. Storage: -40 to +85°C, 10–95% RH. |
| Temperature coefficient |
±0.03%/°C over 0–50°C. |
| Vibration |
Component: 10–500 Hz, 2 G, 10 minutes per cycle and 60 minutes along each X, Y and Z axis. Mounting complies with IEC60068-2-6. |
| High-altitude derating |
For this fanless supply, reduce the allowable ambient temperature by 3.5°C per additional 1000 m above 2000 m (6500 ft). This note does not specify a maximum operating altitude. |
Apply input-voltage and temperature limits together. The published overload range is not a substitute for these operating limits.
Dimensions, Terminals and Installation
| Dimensions / case |
40 × 125.2 × 113.5 mm (W × H × D); case 992D, mechanical drawing tolerance ±1 mm. |
| Compatible DIN rail |
TS-35/7.5 or TS-35/15; the drawing shows a 35 mm rail profile. The rail is for reference and is not included with the unit. |
| Input terminal block TB1 |
Pin 1: FG protective earth; pin 2: AC/N or DC negative; pin 3: AC/L or DC positive. |
| Output terminal block TB2 |
Pins 1–2: DC output -V; pins 3–4: DC output +V. |
| Installation clearances |
For permanent full-power loading, the catalogue recommends 40 mm above, 20 mm below and 5 mm on each side. Where an adjacent device is a heat source, allow 15 mm clearance. |
| Installation details |
Use the complete mechanical drawing, the supplied unit’s markings and the manufacturer’s installation instructions for the rail attachment and wiring. |
These model pages do not provide a separate mounting-kit, terminal-kit or connector ordering code. Do not infer that a rail or additional wiring accessory is supplied.
Safety, Insulation and EMC
| Catalogue-listed safety |
UL508 and TUV BS EN/EN62368-1; EAC TP TC004 approved. The table states compliance with BS EN/EN60204-1. |
| Withstand voltage |
Input–output: 3 kVAC; input–FG: 2 kVAC; output–FG: 0.5 kVAC. |
| Insulation resistance |
More than 100 MΩ for input–output, input–FG and output–FG at 500 VDC, 25°C and 70% RH. |
| EMC emissions |
BS EN/EN55032 (CISPR32), BS EN/EN61204-3 Class B, BS EN/EN61000-3-2 and -3; EAC TP TC020. |
| EMC immunity |
BS EN/EN61000-4-2, -3, -4, -5, -6, -8 and -11; BS EN/EN55035; BS EN/EN61000-6-2 (BS EN/EN50082-2); BS EN/EN61204-3, heavy-industry level; EAC TP TC020. |
The supply is a component to be installed in final equipment. Reconfirm that the completed equipment meets the applicable EMC directives.
Weight, Reliability and Reference Conditions
| Catalogue unit weight |
600 g, converted from the explicit 0.6 kg PACKING reference per unit; not a measured net weight, shipping weight or carton-weight average. |
| MTBF |
2636.8 K hours minimum, Telcordia SR-332 (Bellcore); 453.3 K hours minimum, MIL-HDBK-217F at 25°C. These are reliability references, not guaranteed operating life. |
| Manufacturer test / warranty statement |
The catalogue lists a 100% full-load burn-in test and three-year warranty. Applicable manufacturer terms govern warranty coverage. |
| Default test conditions |
Unless otherwise specified: 230 VAC input, rated load and 25°C ambient. |
| Applicable datasheet |
NDR-120-SPEC, 2026-04-03; combined NDR/EDR catalogue pages 5–8. |
