MORNSUN LM75-20B05 Series: 75W AC/DC Enclosed Switching Power Supply

MORNSUN POWER
Jan 20
4 min read

Product Overview

The MORNSUN LM75-20B05 Series is a highly reliable, high-performance 75W enclosed switching power supply (SMPS) designed for a wide range of industrial applications. It features a compact metal enclosure, high efficiency up to 89%, and delivers stable and clean DC power. This series is engineered for demanding environments, offering excellent electromagnetic compatibility (EMC) performance, comprehensive protection features, and adherence to international safety standards. It is an ideal power solution for industrial control systems, telecommunications, office automation, and other equipment requiring dependable 75W power.

Key Features

Wide Input Voltage Range: Universal input of 85 - 264VAC (47-63Hz) or 120 - 370VDC.
High Efficiency & Low Standby Power: Typical efficiency up to 89%. Standby power consumption is less than 0.5W.
Comprehensive Protection: Built-in protection against Over-Current (OCP), Over-Voltage (OVP), and Short-Circuit (SCP). All protections feature auto-recovery.
Excellent EMC Performance: Designed to meet Class B EMI limits per CISPR32/EN55032 standards, with high immunity to interference.
High Reliability & Safety: Features a 3000VAC isolation voltage (I/O). Designed and certified to meet UL62368-1, EN62368-1, and GB4943.1 safety standards. Certified with CE, UKCA, and RCM marks. ROHS compliant.
Cooling & Environmental: Cooled by free air convection. Operating temperature range from -30°C to +70°C (with derating above +50°C).

Model Selection and Output Parameters

The LM75-20B05 series offers four standard single-output models. The output voltage can be finely adjusted within a specified range using a potentiometer (clockwise to increase voltage).

Model LM75-20B05: Nominal output 5V at 15.0A. Output voltage adjustable range: 4.5 - 5.5V. Typical efficiency (230VAC): 84%.
Model LM75-20B12: Nominal output 12V at 6.5A. Output voltage adjustable range: 10.8 - 13.2V. Typical efficiency (230VAC): 88%.
Model LM75-20B15: Nominal output 15V at 5.0A. Output voltage adjustable range: 13.5 - 16.5V. Typical efficiency (230VAC): 89%.
Model LM75-20B24: Nominal output 24V at 3.2A. Output voltage adjustable range: 21.6 - 26.4V. Typical efficiency (230VAC): 89%.

Detailed Technical Specifications

Input Characteristics

Input Voltage Range: 85 - 264VAC; 120 - 370VDC.
Input Frequency Range: 47 - 63 Hz.
Input Current (Max.): 2.0A at 115VAC; 1.2A at 230VAC.
Inrush Current (Max.): Cold start: 40A at 115VAC, 70A at 230VAC.
Leakage Current: <1.0mA at 264VAC.
AC Input Surge Protection: Capable of withstanding a 2KV combination wave (Line to Line) and a 4KV combination wave (Line to Earth) per IEC61000-4-5 Level 3.
Efficiency: Typical 89% at 230VAC, full load (15V/24V models).
Standby Power Consumption: <0.5W at 230VAC input, no load.

Output Characteristics

Output Voltage Accuracy (Line Regulation): ±1.0% (for input voltage variation from low line to high line at full load).
Output Voltage Accuracy (Load Regulation): ±2.0% (from 0% to 100% load change).
Start-up & Hold-up Time: Start-up time is typically 1500ms at full load, 115VAC. Hold-up time is typically 16ms at full load, 115VAC.
Output Ripple & Noise: Measured with a 20MHz bandwidth. 5V model: 100mVp-p max; 12V model: 120mVp-p max; 15V model: 150mVp-p max; 24V model: 200mVp-p max.
Over-Current Protection (OCP): Hiccup mode. The power supply will shut down and auto-restart periodically until the overload condition is removed.
Over-Voltage Protection (OVP): Latching mode for 5V, 12V, 15V models; Hiccup mode for 24V model. The output will be shut down and require a power cycle (or will auto-retry) when the fault is cleared.
Short-Circuit Protection (SCP): Hiccup mode. Auto-recovery.
Temperature Coefficient: ±0.03%/°C typical.

General Characteristics

Isolation Characteristics:
- Isolation Voltage (Input-Output): 3000VAC for 1 minute.
- Insulation Resistance (Input-Output): >100 MΩ at 500VDC.
Environmental Specifications:
- Operating Temperature: -30°C to +70°C (Refer to derating curve for operation above +50°C).
- Storage Temperature: -40°C to +85°C.
- Operating & Storage Humidity: 20% - 90% RH, non-condensing.
Derating:
- Output Power Derating vs. Temperature: 100% rated power from -30°C to +50°C. Derating linearly to 60% at +70°C.
- Output Power Derating vs. Input Voltage: 100% rated power from 100VAC to 264VAC. Derating linearly to 80% at 85VAC.
Safety & Compliance:
- Safety Standards: Compliant with UL62368-1, EN62368-1, GB4943.1. Safety Class I construction.
- Certifications & Marks: CE, UKCA, RCM.
- Withstand Voltage: 3000VAC.
- Creepage & Clearance: Meets requirements for reinforced insulation.
- EMC Standards: Conducted & Radiated EMI meets CISPR32/EN55032 Class B. EMS immunity meets IEC/EN61000-4-2,4,5,6,8,11.
Reliability:
- MTBF: >500,000 hours per MIL-HDBK-217F at 25°C.
Physical Specifications:
- Dimensions (L x W x H): 159mm x 98mm x 38mm.
- Weight: Approximately 440g.
- Enclosure Material: Metal case (U-shaped chassis).
- Input/Output Connections: Screw terminal blocks.
- Cooling: Free air convection (fanless).
- Mounting: 4x mounting holes on the base.
- Potentiometer: For output voltage adjustment (V.ADJ).

EMC Characteristics Summary

The LM75-20B05 series is designed for robust EMC performance in industrial environments.

Electromagnetic Emissions (EMI): Conforms to CISPR32/EN55032 Class B limits for both conducted and radiated emissions.
Electromagnetic Immunity (EMS):
- Electrostatic Discharge (ESD): IEC/EN61000-4-2, Level 3 (±6kV contact, ±8kV air).
- Radiated RF Immunity: IEC/EN61000-4-3, 10V/m.
- Electrical Fast Transient (EFT/Burst): IEC/EN61000-4-4, Level 3 (±2kV on power lines).
- Surge Immunity: IEC/EN61000-4-5, Level 3 (Line-Line: ±2kV; Line-Earth: ±4kV).
- Conducted RF Immunity: IEC/EN61000-4-6, 10V.
- Power Frequency Magnetic Field: IEC/EN61000-4-8, 30A/m.
- Voltage Dips & Interruptions: Compliant with IEC/EN61000-4-11.

Important Installation & Usage Notes

Thermal Management: Ensure adequate ventilation. Do not obstruct ventilation slots. Maintain recommended clearances from walls or other heat sources. The unit is designed for convection cooling.
Mounting: Mount in the correct orientation as shown in the dimensional drawing. Use the provided four mounting holes.
Wiring: Use appropriate wire gauges for the input and output current. Ensure terminals are tightened to the specified torque. Connect the protective earth (PE) terminal for safety.
First Use: Before applying power, verify that the input voltage matches your mains supply and that the output voltage setting is correct for your load.
Adjustment: The output voltage can be fine-tuned within the specified range using the V.ADJ potentiometer located on the side of the unit. Turn clockwise to increase voltage.
Safety: The power supply is intended for installation as a component within a finished end product. The final equipment manufacturer is responsible for ensuring the complete system complies with all applicable safety and EMC standards.