1. Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of the Mean Well LRS-350-24 DC Switching Power Supply. This 350W single-output enclosed type power supply features a 30mm low profile design, accepting input of 115VAC or 230VAC (selectable by switch). It is designed for various industrial applications, including automation machinery, industrial control systems, mechanical and electrical equipment, and electronic instruments.
2. Safety Information
WARNING: Risk of electric shock. Installation and servicing should only be performed by qualified personnel.
- Before connecting the power supply, ensure the input voltage selection switch is set correctly to either 115VAC or 230VAC to match your local power grid. Incorrect setting can cause damage to the unit. The switch is set to 115VAC by default.
- Always disconnect the AC input power before making any connections or adjustments to prevent electric shock.
- Ensure proper grounding of the unit to prevent electrical hazards.
- Do not operate the power supply in environments with excessive moisture, dust, or extreme temperatures outside its specified operating range.
- Ensure adequate ventilation around the unit to prevent overheating. The built-in fan operates based on internal temperature.
- Do not open the power supply casing. There are no user-serviceable parts inside.
3. Features
- AC input range selectable by switch (90 ~ 132VAC / 180 ~ 264VAC).
- Withstands 300VAC surge input for 5 seconds.
- Comprehensive protections: Short Circuit, Overload, Over Voltage, Over Temperature.
- Forced air cooling by built-in DC fan.
- Built-in cooling fan ON-OFF control, activating when case temperature exceeds 122℉ (50℃).
- 1U low profile design.
- Withstands 5G vibration test.
- LED indicator for power on.
- No load power consumption less than 0.75W.
- 100% full load burn-in test.
- High operating temperature up to 70℃.
- Operating altitude up to 5000 meters.
- High efficiency, long life, and high reliability.
4. Applications
- Industrial automation machinery
- Industrial control system
- Mechanical and electrical equipment
- Electronic instruments and apparatus
5. Product Overview
6. Setup and Installation
6.1 Input Voltage Selection
The LRS-350-24 features an input voltage selection switch. Before connecting the AC power, ensure this switch is set to the correct voltage for your region (115VAC or 230VAC). The switch is typically located on the side of the unit, as shown in Figure 2. The factory default setting is 115VAC.
6.2 Wiring Instructions
Refer to Figure 2 for the terminal block layout. Connect the AC input and DC output wires as follows:
- AC Input: Connect the Live (L), Neutral (N), and Ground (⏚) wires to the corresponding terminals.
- DC Output: Connect the positive (+) and negative (-) load wires to the respective output terminals. The LRS-350-24 provides multiple terminals for both positive and negative outputs to facilitate easier wiring for higher current applications.
Ensure all connections are secure and properly insulated. Use appropriate wire gauges for the expected current load.
6.3 Mounting
The power supply is designed for benchtop use or integration into systems. Mounting brackets are not included with the unit. Refer to the Mechanical Specification section for detailed dimensions and mounting hole locations if custom mounting is required.
7. Operating Instructions
7.1 Power On
Once all connections are secure and the input voltage is correctly selected, apply AC power. The power-on LED indicator will illuminate, signifying normal operation.
7.2 Output Voltage Adjustment
The LRS-350-24 features a trim-pot (potentiometer) for fine-tuning the output voltage. This adjustment allows for a slight variation around the nominal 24V output. Use a small screwdriver to carefully turn the trim-pot clockwise to increase voltage or counter-clockwise to decrease it. Monitor the output voltage with a multimeter during adjustment.
7.3 Fan Operation
The built-in DC fan is thermostatically controlled. It will activate automatically when the internal case temperature exceeds 122℉ (50℃) to maintain optimal operating temperatures and ensure longevity of the unit. The fan may not run continuously, depending on the load and ambient temperature.
8. Maintenance
The Mean Well LRS-350-24 power supply requires minimal maintenance. Follow these guidelines to ensure optimal performance and lifespan:
- Keep the unit clean and free from dust and debris, especially around the ventilation openings and fan grille. Use a soft, dry cloth for cleaning.
- Ensure that there is always adequate airflow around the power supply. Do not block the fan or ventilation holes.
- Periodically check all wiring connections to ensure they remain secure.
- Avoid operating the unit in environments that exceed its specified temperature and humidity ranges.
9. Troubleshooting
If the power supply is not functioning as expected, consider the following:
- No Power Output:
- Check the AC input power source.
- Verify the input voltage selection switch is set correctly (115VAC or 230VAC).
- Ensure all input and output wires are securely connected.
- Check if the power-on LED indicator is illuminated.
- Intermittent Output or Shutdown:
- The unit may be triggering its overload or over-temperature protection. Reduce the load or ensure proper ventilation.
- Check for short circuits in the output wiring or connected load.
- Fan Not Running:
- The fan is thermostatically controlled and only activates when the internal temperature exceeds 122℉ (50℃). If the unit is cool and under light load, the fan may not be active, which is normal.
- If the unit is hot and the fan is not running, ensure the fan grille is not obstructed.
If issues persist after checking these points, contact technical support.
10. Specifications
| Parameter | Value |
|---|---|
| Output Voltage | 24V |
| Rated Current | 14.6A |
| Rated Power | 350W |
| Input Voltage Range | 90 ~ 132VAC / 180 ~ 264VAC (selectable by switch) |
| Efficiency (Typ.) | 88% |
| Frequency Range | 47 ~ 63Hz |
| Overload Protection | 110 ~ 140% rated output power, hiccup mode, auto-recovery |
| Over Voltage Protection | 28.8 ~ 33.6V, hiccup mode, auto-recovery |
| Over Temperature Protection | Shut down and latch off o/p voltage, auto-recovery |
| Working Temp. | -25 ~ +70℃ (Refer to Derating Curve) |
| Working Humidity | 20 ~ 90% RH non-condensing |
| Storage Temp., Humidity | -40 ~ +85℃, 10 ~ 95% RH |
| Vibration | 10 ~ 500Hz, 5G 10min./1cycle, 60min. each along X, Y, Z axes |
| Dimensions (L x W x H) | 215 x 115 x 30 mm (8.46 x 4.53 x 1.18 inches) |
| Weight | 0.76kg (1.67 lbs) |
11. Technical Diagrams
11.1 Block Diagram
11.2 Derating Curve
11.3 Static Characteristics
11.4 Mechanical Specification
12. Warranty and Support
The Mean Well LRS-350-24 DC Switching Power Supply is manufactured to high-quality standards and typically comes with a manufacturer's warranty. Please refer to the warranty card included with your product or visit the official Mean Well website for specific warranty terms and conditions.
For technical support, troubleshooting assistance beyond this manual, or service inquiries, please contact your authorized Mean Well distributor or the manufacturer directly. Ensure you have your product model number (LRS-350-24) and purchase information available when seeking support.