MEAN WELL SDR-120-24 is a single-output industrial DIN rail power supply rated at 24 V DC, 5 A and 120 W. It combines an adjustable output, free-air convection and mounting on TS-35/7.5 or TS-35/15 rail. Built-in active PFC and a DC OK relay contact support industrial control installations. The specified 180 W peak is a short-duration capability, subject to the loading patterns and input/temperature curves below.
Product Datasheet
Download MEAN WELL SDR-120 Datasheet (PDF)
The SDR-120 section is on PDF pages 4, 5, 6. Refer to the complete mechanical drawings and notes when planning installation.
Model and DC Output
| Complete model |
SDR-120-24; SDR-120 catalogue revision 2025-06-09. The final code denotes 24 V nominal output. |
| Continuous rating |
24 V DC / 5 A / 120 W; output-current range 0–5 A. |
| Voltage adjustment |
24–28 V, using +V ADJ. Observe the model’s current and power limits when adjusting. |
| Ripple and noise |
100 mVp-p maximum; 20 MHz bandwidth, a 12-inch twisted pair and parallel 0.1 µF / 47 µF termination capacitors. |
| Voltage tolerance |
±1.0%, including setup tolerance, line regulation and load regulation. |
| Line / load regulation |
±0.5% / ±1.0%, respectively. |
| Typical efficiency |
91% at the default 230 VAC input, rated-load and 25°C ambient test conditions. |
Use the published complete-model continuous and peak ratings; the series number and family-wide efficiency headline do not replace the individual model values.
Peak Loading and Repetition Conditions
| Peak current / power |
7.5 A / 180 W, for a maximum of 3 seconds. The catalogue describes this as 150% peak-load capability. |
| Loading pattern 1 |
The published waveform alternates 120 W for 100 seconds with 180 W for 3 seconds. |
| Loading pattern 2 |
The second waveform alternates 60 W for 15 seconds with 180 W for 3 seconds. |
These are the two specific loading patterns on PDF page 6, not permission to repeat the peak at an arbitrary duty cycle. Keep every peak within 3 seconds and apply the applicable peak-temperature curve and input derating. Continuous loading must follow the separate continuous curve.
The 180 W peak does not replace the 120 W continuous rating, and overload protection is not a continuous operating mode.
Input and Timing
| Input range |
88–264 VAC or 124–370 VDC; AC frequency 47–63 Hz. |
| Typical AC current |
1.4 A at 115 VAC; 0.7 A at 230 VAC. |
| Typical inrush current |
35 A at 115 VAC; 70 A at 230 VAC. |
| Setup / rise at full load |
1500 / 60 ms at 230 VAC; 3000 / 60 ms at 115 VAC. |
| Typical hold-up at full load |
20 ms at 230 VAC; 20 ms at 115 VAC. |
| Leakage current |
Less than 1 mA at 240 VAC. |
| Power factor, typical |
0.93 at 230 VAC and 0.96 at 115 VAC, at full load; built-in active PFC. |
Unless otherwise specified, parameters are measured at 230 VAC input, rated load and 25°C ambient. Low input voltage requires load derating.
Protection
| Overload: lower range |
At 110–150% of rated output power, the catalogue describes operation for more than 3 seconds followed by output shutdown. |
| Short-circuit / overload: higher range |
Above 150% of rated power, constant-current limiting has automatic recovery within the first 3 seconds; after 3 seconds the output shuts down. |
| Overvoltage |
29–33 V; output shuts down, then re-power to recover. |
| Overtemperature sensing |
95 ±5°C, detected by TSW on power-switch heatsink. This is an internal sensing temperature, not an ambient rating. |
| Overtemperature recovery |
Output shuts down and recovers automatically after temperature falls. |
The overload time description is a protection response. It does not extend the separately specified 3-second maximum peak-loading period.
DC OK Relay Contact
| Relay closed |
Power supply on / DC OK. |
| Relay open |
Power supply off / DC fail. |
| Contact ratings, maximum |
60 VDC / 0.3 A, 30 VDC / 1 A, or 30 VAC / 0.5 A, for resistive loads, as listed in the specification. The function table also lists the 30 V / 1 A resistive rating. |
| Connection |
TB2 pins 1 and 2 are the relay contact. They are separate from TB2 pin 3 (−V) and pin 4 (+V). |
The contact indicates status; it is not a specified powered logic-voltage output. Select the monitoring circuit within the applicable resistive-load contact rating.
Cooling, Derating and Environment
| Cooling / orientation |
Free-air convection; the published temperature curves are for vertical mounting. |
| Working ambient range |
-25 to +70°C, subject to the input and thermal conditions below. |
| Continuous temperature curve |
The 24 V branch shows 100% load up to 60°C, then decreases along the plotted line to 75% at 70°C. |
| Short-peak temperature curve |
The 24 V branch shows the 150% short-peak level up to 60°C, decreasing to 125% at 70°C. The 3-second limit and published absolute peak-power rating still apply. |
| Input-voltage curve, 60 Hz |
The graph shows 90% load at 88 VAC, rising to 100% at 100 VAC. The 100% plateau continues through 264 VAC. |
| Working humidity |
20–95% RH, non-condensing. |
| Storage |
−40 to +85°C; 10–95% RH. |
| Temperature coefficient |
±0.03%/°C over 0–50°C. |
| Vibration |
10–500 Hz, 2G, 10 min/cycle and 60 min on each X, Y and Z axis; mounting compliance IEC60068-2-6. |
| High-altitude derating |
For this fanless model, reduce the permitted ambient temperature by 3.5°C per 1000 m above 2000 m, as specified by the catalogue footnote. |
Apply the input and temperature limits together. The maximum ambient temperature is not a full-load rating, and the short-peak curve must not be used as the continuous curve.
Dimensions, Wiring and Installation
| Body size |
40 × 125.2 × 113.5 mm (W × H × D), case 992A; general drawing tolerance ±1 mm. |
| DIN rail compatibility |
TS-35/7.5 or TS-35/15; the mechanical drawing shows a 35 mm rail profile. |
| Input terminal block TB1 |
pin 1: FG; pin 2: AC/N; pin 3: AC/L. |
| Output terminal block TB2 |
pins 1,2: DC OK relay contact; pin 3: −V; pin 4: +V. |
| Indication / adjustment |
The mechanical drawing identifies the DC OK indicator and +V ADJ output-voltage control. |
| Recommended installation clearances |
For permanent full-power loading: 40 mm above, 20 mm below, and 5 mm on both left and right sides. When the adjacent device is a heat source, 15 mm clearance is recommended. |
| Catalogue unit weight |
670 g per unit, from the explicit PACKING reference. Full entry: 0.67 kg; 20 pcs / 14.4 kg / 1.0 CUFT. Carton gross mass is not the unit weight. |
Use the exact terminal numbering and rail-latch geometry on PDF page 5; connect FG protective earth and follow the supplied unit’s installation instructions and terminal markings. Rail compatibility does not mean that a rail is supplied. The assigned pages list no separately orderable MEAN WELL rail, bracket, cover or connector accessory code.
Safety, Insulation and EMC
| Catalogue-listed safety approvals |
UL508; TUV BS EN/EN62368-1; AS/NZS62368.1; EAC TP TC004. BSMI CNS15598-1 is also listed. |
| Additional standards statement |
Meets BS EN/EN60204-1. |
| Withstand voltage |
Input–output: 3 kVAC; input–FG: 2 kVAC; output–FG: 0.5 kVAC. Output–DC OK contact: 0.5 kVAC. |
| Insulation resistance |
Greater 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; CNS15936 Class B. |
| EMC immunity and voltage-dip compliance |
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; SEMI F47 approved. |
The power supply is a component intended for final equipment. Reconfirm EMC compliance in the completed equipment; the component listings do not certify the whole installation.
Reliability and Manufacturer Information
| MTBF reference |
1764.6 K hours minimum under Telcordia SR-332 (Bellcore); 292.1 K hours minimum under MIL-HDBK-217F at 25°C. These are reliability references, not a guaranteed service life. |
| Factory test / warranty |
The catalogue lists 100% full-load burn-in testing and a three-year warranty, subject to applicable manufacturer terms. |
