MEAN WELL LRS-350-12 Switching Power Supply User Manual

1. Introduction

This manual provides essential information for the safe and efficient use of your MEAN WELL LRS-350-12 Switching Power Supply. This unit is designed to provide a stable 12V DC output from an AC input, suitable for various applications including LED projects, industrial automation, and electronic instruments.

Please read this manual thoroughly before installation and operation, and retain it for future reference.

2. Safety Instructions

• Electrical Hazard: This unit operates with high voltage. Installation and maintenance should only be performed by qualified personnel.
• Input Voltage Selection: Ensure the AC input voltage switch is set correctly (115VAC or 230VAC) before connecting to power. Incorrect setting can cause damage.
• Ventilation: Ensure adequate ventilation around the power supply to prevent overheating. Do not block ventilation openings.
• Grounding: Always connect the protective earth (ground) terminal to a proper ground connection.
• Overload Protection: Do not exceed the rated output current (29A) or power (348W) to prevent damage and ensure safe operation.
• Environment: Do not expose the unit to moisture, rain, or excessive dust. Operate within specified temperature and humidity ranges.

3. Product Features

• Output Voltage: 12V DC
• Rated Current: 29A
• Rated Power: 348W
• Input Voltage Range: 90 ~ 132VAC / 180 ~ 264VAC (selectable by switch)
• Built-in cooling FAN with ON-OFF control (activates at RTH3 ≥ 50℃, turns off at RTH3 ≤ 40℃)
• Protections: Short Circuit, Overload, Over Voltage, Over Temperature
• Certifications: UL and CE

4. Setup and Installation

Follow these steps for proper installation of your LRS-350-12 power supply.

4.1 Unpacking

Carefully remove the power supply from its packaging. Inspect the unit for any physical damage. If damage is found, do not proceed with installation and contact your supplier.

4.2 Input Voltage Selection

Before connecting any power, ensure the AC input voltage selection switch is set to the correct voltage for your region (115VAC for North America, 230VAC for most other regions). This switch is typically located on the side of the unit.

Image: Side view of the LRS-350-12 power supply, highlighting the red switch for AC input voltage selection (115V/230V).

Warning: Failure to set the correct input voltage before powering on will result in damage to the unit.

4.3 Wiring Connections

The LRS-350-12 uses screw terminal blocks for both AC input and DC output connections. Refer to the labels on the unit for correct terminal identification.

Image: Detailed view of the LRS-350-12 terminal block, showing connections for AC input (L, N, Ground) and DC output (+V, -V).

1. AC Input: Connect your AC mains power to the terminals labeled 'L' (Live), 'N' (Neutral), and '⊗' (Ground). Ensure secure connections.
2. DC Output: Connect your load to the terminals labeled '+V' (Positive 12V DC) and '-V' (Negative/Ground). Multiple '+V' and '-V' terminals are provided for convenience and to distribute current.
3. Voltage Adjustment: A small potentiometer (labeled 'V.ADJ' or similar) is available near the output terminals to fine-tune the output voltage within a small range. Use a small screwdriver to adjust if necessary.

5. Operating Instructions

1. Initial Power-Up: After all connections are secure and the input voltage switch is correctly set, apply AC power to the unit.
2. Indicator LED: A green LED indicator (if present) will illuminate, signifying that the power supply is operational.
3. Load Connection: Connect your 12V DC load to the output terminals. Ensure the total current draw does not exceed 29A.
4. Cooling Fan: The built-in cooling fan operates automatically. It will turn on when the internal temperature (RTH3) reaches 50℃ and turn off when it drops below 40℃. This ensures optimal operating temperature.

6. Maintenance

• Cleaning: Periodically clean the exterior of the power supply with a dry, soft cloth. Ensure ventilation openings are free from dust and debris to maintain proper airflow for the cooling fan.
• Connection Checks: Regularly inspect all wiring connections to ensure they are tight and secure. Loose connections can lead to poor performance or safety hazards.
• Environmental Conditions: Ensure the operating environment remains within the specified temperature and humidity ranges to prolong the lifespan of the unit.

Image: Top view of the LRS-350-12 power supply, illustrating the cooling fan and ventilation slots crucial for heat dissipation.

7. Troubleshooting

8. Specifications

9. Warranty and Support

For warranty information, please refer to the documentation provided with your purchase or contact your authorized MEAN WELL distributor or reseller. Warranty terms and conditions may vary by region and point of purchase.

For technical support or further inquiries, please visit the official MEAN WELL website or contact their customer service department. The manual reference on the product label points to www.meanwell.com/manual.html for additional resources.