MEAN WELL LRS-450-5 is a single-output enclosed switching power supply with a 5 V DC output, 75 A rated current and 375 W rated output power. 115/230 VAC selector switch. Forced air cooling by built-in DC fan.
Download MEAN WELL LRS-450 Datasheet (PDF)
The combined LRS catalog includes this series on PDF pages 48–51. Specifications: page 49; mechanical drawing: page 51.
Model and Output Specifications
| Complete model |
LRS-450-5 |
| Series |
LRS-450 |
| Output-voltage code |
5 = 5 V DC nominal output |
| Rated output voltage |
5 V DC |
| Rated output current |
75 A |
| Output current range |
0 to 75 A |
| Rated output power |
375 W |
| Output voltage adjustment |
4.75 to 5.5 V |
| Ripple and noise, maximum |
200 mVp-p |
| Voltage tolerance |
±2.0% |
| Line regulation |
±0.5% |
| Load regulation |
±2.0% |
| Efficiency, typical |
87% at the stated test conditions |
230 VAC input, rated load, 25°C ambient unless otherwise stated. Ripple/noise test: 20 MHz bandwidth; 12-inch twisted-pair wire terminated with 0.1 µF and 47 µF parallel capacitors.
Voltage tolerance includes setup tolerance, line regulation and load regulation. Line regulation is measured from low to high input at rated load; load regulation is measured from 0% to 100% rated load.
Adjust output voltage only with input at 100–120 VAC or 200–240 VAC. Adjustment outside these input ranges may cause abnormal output.
Input and Timing
| AC input range |
90 to 132 VAC / 180 to 264 VAC |
| Input range selection |
115/230 VAC selector switch |
| DC input range |
255 to 370 VDC. Set switch to 230 VAC for DC input. |
| Input frequency |
47 to 63 Hz |
| AC input current, typical |
10A/115VAC 6A/230VAC |
| Inrush current, typical |
35A/115VAC 60A/230VAC |
| Leakage current |
<2mA / 240VAC |
| Setup / rise time |
1500 / 50 ms at 230 VAC; 1500 / 50 ms at 115 VAC, full load |
| Hold-up time, typical |
16 ms at 230 VAC; 12 ms at 115 VAC, full load |
| Transient input withstand |
300 VAC for 5 seconds; this is a surge condition, not the continuous input rating |
Full load; setup at cold first start. Rapid on/off cycling can increase setup time.
Select the correct 115/230 VAC input range before energizing the supply. For DC input, the selector must be set to 230 VAC.
Protection and Recovery
| Short-circuit protection |
Included |
| Overload |
105 to 150% of rated output power. Constant-current limiting; shuts down after 3 seconds; re-power on to recover. |
| Overvoltage protection |
5.75 to 6.75 V. Shut down output; re-power on to recover. |
| Thermal protection |
Shut down output; re-power on to recover. |
| Restart after protection |
Allow 3 minutes of cool-down, typical, before restarting. |
Environment and Cooling
| Ambient operating temperature |
-20 to 70 °C; apply the temperature and input-voltage derating curves |
| Cooling |
Forced air cooling by built-in DC fan |
| Working humidity |
20 ~ 90% RH non-condensing |
| Storage temperature / humidity |
-40 ~ +85°C, 10 ~ 95% RH |
| Temperature coefficient |
±0.03%/°C (0 ~ 50°C) |
| Fan control, typical |
Internal RTH3 sensor: fan on at ≥50 °C and off at ≤40 °C. These are internal sensor temperatures, not ambient-temperature setpoints. |
| Operating altitude |
Up to 5,000 m as stated for this series; the applicable overvoltage category and temperature derating impose additional limits. |
| Overvoltage category |
Category III up to 2,000 m under the standards specified in this series datasheet. This is an insulation category, separate from the output-overvoltage protection threshold. |
| Higher-altitude temperature derating |
For operation above 2,000 m, reduce the permitted ambient temperature by 5 °C per additional 1,000 m. Verify the applicable insulation/approval limits for the installation. |
Full rated output is not available at every point within the temperature and input ranges. Use the ambient-temperature and static input-voltage curves on PDF page 50 for this model and installation orientation.
Dimensions and Installation
| Overall dimensions (L × W × H) |
225 × 124 × 35 mm |
| Case number |
291 |
| Drawing tolerance |
±1 mm |
| Mounting-hole callouts |
4-M4 L=3mm; 4-M4(Both Sides) L=6mm |
| Terminal 1 |
AC/L |
| Terminal 2 |
AC/N |
| Terminal 3 |
FG (protective earth) |
| Terminal 4~6 |
DC OUTPUT -V |
| Terminal 7~9 |
DC OUTPUT +V |
Use the mechanical drawing on PDF page 51 to locate the holes and confirm the permitted screw penetration for the selected mounting face. The M3/M4 callouts are mounting dimensions, not accessory ordering codes. Match wiring, protective-earth connection and output polarity to the terminal markings. Keep the ventilation path and the airflow direction shown in the drawing clear.
This enclosed supply is a component for installation inside final equipment. Complete installation and electrical work using the manufacturer’s installation instructions and the applicable equipment requirements.
Reference Weight
| Catalog reference per unit |
850 g |
This value is the per-unit reference in the manufacturer’s PACKING row. It is not a measured net weight or a quotation for the complete shipping package.
Application and Datasheet Notes
The manufacturer states that this supply does not meet EN61000-3-2 harmonic-current requirements. Do not use it in end equipment within the European Union that is connected to public mains rated at 220 VAC or above when the end equipment has average or continuous input power greater than 75 W, or when it forms part of a lighting system. The datasheet lists exceptions for professional equipment with total rated input power greater than 1,000 W and for symmetrically controlled heating elements rated at 200 W or less. Confirm the applicability to the complete end equipment.
EMC results are for a component installed on the manufacturer’s specified test plate. The finished equipment must be checked again for EMC compliance. Safety approvals and regional exceptions depend on the exact model and datasheet revision; refer to the linked specification and applicable certificates when selecting the unit.
Additional Manufacturer Data
| Vibration test |
10 ~ 500Hz, 5G 10min./1cycle, 60min. each along X, Y, Z axes |
| MTBF reference |
1508.9K hrs min. Telcordia SR-332(Bellcore) ; 252.2K hrs min. MIL-HDBK-217F (25°C) |
| Dielectric withstand |
I/P-O/P:3.75KVAC I/P-FG:2KVAC O/P-FG:0.5KVAC |
| Manufacturer datasheet warranty |
3 years; subject to the manufacturer’s applicable warranty terms |
MTBF is a reliability prediction under the stated method and conditions, not a service-life or warranty-duration guarantee.
Source: MEAN WELL LRS-450 datasheet, revision 2025-09-12, in the linked LRS catalog. Use the exact model specification, notes and drawings together when selecting and installing this supply.
