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Mean Well LOP-300-12 300W 4"×2" Low Profile Open Frame Power Supply 12V 15A

conventional 180W300W if using fanhigh frequency up to 94%

SKU LOP-300-12

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Overview

LOP-300-12 is the 12V output model of this series: typical efficiency 92.5%.

The LOP-300 is a 300W highly reliable, energy-efficient, low-profile open frame type power supply. With a high power density of 37.5W/in³ within the standard size of 4" × 2", it features a universal input voltage range of 80~264VAC, making it suitable for global applications. The series offers a comprehensive selection of standard voltages, including 12V/15V/18V/24V/27V/30V/36V/48V/54V, and comes in a complete range of models. The main features of the LOP-300 include: low standby power (<0.5W), high efficiency (up to 94%), capable providing 180W under natural air cooling and 300W with an additional fan. It has a 150% @ 3 seconds peakload capacity, a wide operating temperature range of -40 to +80℃, compliance with OVCⅢ, suitable for Class Ⅰ (with FG) or Class Ⅱ (without FG) systems. The product has obtained multiple safety certifications, including 62368-1/60601-1/61558-1/60335-1, and is designed to meet 2xMOPP and extremely low touch leakage current <70 μ A, making it suitable for BF class medical devices. With high product safety and excellent EMC performance, it is versatile and applicable in various fields such as ITE, medical, industrial control, home automation and more. It is a cost-effective slim open frame type power supply.

Features

MEAN WELL Patent Number: ZL 202223277512.1
4"×2" compact size with low profile (25.4mm)
80~264Vac input with PFC, No load power consumption<0.5W
Global certificates in multi-fields (ITE 62368-1, Medical 60601-1, Household 60335-1, Industrial 61558-1/-2-16)
150%peak load @ 3s
180W convection, 300W with FAN 10.98CFM forced-cooled
Suitable for Class Ⅰ or Class Ⅱ installations
Over voltage category Ⅲ (OVC Ⅲ)
-40 ~ +80℃ wide range operation temperature
High efficiency up to 94%
Protections: Short circuit / Overload / Over voltage / Over temperature
Extremely low leakage current, 2 x MOPP, suitable for BF medical applications
Operating altitude up to 5000 meters
Built-in 12V/0.5A for external FAN
3 years warranty

Specifications

LOP-300-12Specifications from the official datasheet (2026-09-02 edition)

OUT PUT

DC VOLTAGE: 12V
CURRENT Peak(3sec.): 37.5A
CURRENT 10.98CFM: 25A
CURRENT Convection: 15A
RATED POWER Peak(3sec.): 450W
RATED POWER 10.98CFM: 300W
RATED POWER Convection: 180W
RIPPLE & NOISE (max.)^Note.2: 120mVp-p
VOLTAGE ADJ. RANGE (MAIN OUTPUT): 11.4~12.6V
VOLTAGE TOLERANCE^Note.3: ±3.0%
LINE REGULATION: ±0.5%
LOAD REGULATION: ±1.0%
SETUP, RISE TIME: 1000ms, 30ms/230Vac 1500ms, 30ms/115Vac at full load
HOLD UP TIME (Typ.): 16ms@180W load , 8ms@300W load

INPUT

VOLTAGE RANGE^Note.4: 80 ~ 264Vac 113 ~ 370Vdc
FREQUENCY RANGE: 47 ~ 63Hz
POWER FACTOR: PF>0.95/230Vac PF>0.98/115Vac at full load
EFFICIENCY (Typ.): 92.5%
AC CURRENT (Typ.): 3.5A/115Vac 1.8A/230Vac
INRUSH CURRENT (Typ.): COLD START 40A/115Vac 80A/230Vac
LEAKAGE CURRENT: ClassⅠ: Earth leakage current < 500 μA (rms) @ 264V ac , touch current < 70μA (rms) @ 264V ac ClassⅡ: Touch current < 100 μA (rms) @ 264V ac

PROTECTION

OVERLOAD: 105 ~ 180% rated output power, Protection type : Hiccup after 3 sec, recovers automatically(3 sec) after fault condition is removed
OVER VOLTAGE: 13.2 ~ 15.6V Protection type : Shut down o/p voltage, re-power on to recover
OVER TEMPERATURE: Protection type : Shut down o/p voltage, recovers automatically after temperature goes down or re-power on to recover

FUNCTION

EXTERNAL FAN SUPPLY: 12V@0.5A for driving a fan (10.98CFM) / 12V@0.1A without fan cooling ; Tolerance -20% ~ +15% at main output 20% rated current

ENVIRONMENT

WORKING TEMP.: -40 ~ +80℃ (Refer to "Derating Curve")
WORKING HUMIDITY: 20 ~ 90% RH non-condensing
STORAGE TEMP., HUMIDITY: -40 ~ +85℃, 10 ~ 95% RH non-condensing
TEMP. COEFFICIENT: ±0.03%/℃ (0 ~ 50℃)
VIBRATION: 10 ~ 500Hz, 2G 10min./1cycle, 60min. each along X, Y, Z axes

SAFETY & EMC

SAFETY STANDARDS^Note.5: CB IEC62368-1, IEC60335-1, IEC61558-1/-2-16, IEC60601-1; TUV BS EN/EN62368-1, BS EN/EN60335-1, BS EN/EN61558-1/-2-16, BS EN/EN60601-1(3.2 Version); UL UL62368-1, ANSI / AAMI ES60601-1(3.2 Version) ; CCC GB4943.1 ; RCM AS/NZS 61558-1/-2-16; EAC TPTC 004 approved.
ISOLATION RESISTANCE: Primary-Secondary: 2xMOPP, Primary-Earth:1xMOPP, Secondary-Earth:1xMOPP
OVER VOLTAGE CATEGORY: IEC/EN 61558-1/-2-16(OVC Ⅲ, altitude up to 2000M ) IEC/EN/UL 62368-1 (OVC Ⅱ, altitude up to 5000M ) IEC/EN 60335-1 (OVC Ⅱ, altitude up to 5000M ) IEC/EN 60601-1 (OVC Ⅱ, altitude up to 4000M )
PROTECTIVE EXTRA-LOW VOLTAGE: IEC/EN61558-2-16 (SELV, 12~48V ) IEC/EN/UL 62368-1 (SELV / ES1, 12~48V )
WITHSTAND VOLTAGE: I/P-O/P:4KVac I/P-FG:2KVac O/P-FG:1.5KVac
ISOLATION RESISTANCE: I/P-O/P, I/P-FG, O/P-FG:100M Ohms / 500VDC / 25℃/ 70% RH
EMC EMISSION: Parameter Standard Test Level

Conducted & Radiated BS EN/EN55032(CISPR32) BS EN/EN55011(CISPR11) ClassⅠ: Class B , Class Ⅱ: Class A
Conducted & Radiated BS EN/EN55014(CISPR32) ClassⅠ: Class B
Harmonic Current BS EN/EN61000-3-2 Class A
Voltage Flicker BS EN/EN61000-3-3
EMC IMMUNITY: BS EN/EN55035,BS EN/ EN61000-6-2

Parameter Standard Test Level

ESD BS EN/EN61000-4-2 Level 4, 15KV air; Level 4, 8KV contact
Radiated Susceptibility BS EN/EN61000-4-3 Level 3, 10V/m( 80MHz~2.7GHz ) Table 9, 9~28V/m( 385MHz~5.78GHz )
EFT/Burest BS EN/EN61000-4-4 Level 3, 2KV
Surge BS EN/EN61000-4-5 Level 4, 4KV/Line-FG; 2KV/Line-Line
Conducted BS EN/EN61000-4-6 Level 3, 10V
Magnetic Field BS EN/EN61000-4-8 Level 4, 30A/m
Voltage Dips and interruptions BS EN/EN61000-4-11 ＞95% dip 0.5 periods, 100% dip 1 periods, 30% dip 25 periods, ＞95% interruptions 250 periods

Parameter	Standard	Test Level
Conducted & Radiated	BS EN/EN55032(CISPR32) BS EN/EN55011(CISPR11)	ClassⅠ: Class B , Class Ⅱ: Class A
Conducted & Radiated	BS EN/EN55014(CISPR32)	ClassⅠ: Class B
Harmonic Current	BS EN/EN61000-3-2	Class A
Voltage Flicker	BS EN/EN61000-3-3

Parameter	Standard	Test Level
ESD	BS EN/EN61000-4-2	Level 4, 15KV air; Level 4, 8KV contact
Radiated Susceptibility	BS EN/EN61000-4-3	Level 3, 10V/m( 80MHz~2.7GHz ) Table 9, 9~28V/m( 385MHz~5.78GHz )
EFT/Burest	BS EN/EN61000-4-4	Level 3, 2KV
Surge	BS EN/EN61000-4-5	Level 4, 4KV/Line-FG; 2KV/Line-Line
Conducted	BS EN/EN61000-4-6	Level 3, 10V
Magnetic Field	BS EN/EN61000-4-8	Level 4, 30A/m
Voltage Dips and interruptions	BS EN/EN61000-4-11	＞95% dip 0.5 periods, 100% dip 1 periods, 30% dip 25 periods, ＞95% interruptions 250 periods

OTHERS

MTBF: 2805.6K hrs min. Telcordia SR-332 (Bellcore) ; 384.4K hrs min. MIL-HDBK-217F (25℃)
DIMENSION: 101.6*50.8* 25.4mm (L*W*H)
PACKING: 0.21Kg; 36pcs/10Kg/0.95CUFT

Test conditions and notes5

1. All parameters NOT specially mentioned are measured at 230VAC input, rated load and 25℃ of ambient temperature.
2. Ripple & noise are measured at 20MHz of bandwidth by using a 12" twisted pair-wire terminated with a 0.1 μF & 47 μF parallel capacitor.
3. Tolerance : includes set up tolerance, line regulation and load regulation.
4. Derating may be needed under low input voltages. Please check the derating curve for more details.
5. The power supply is considered a component which will be installed into a final equipment. All the EMC tests are been executed by mounting the unit on a 360mm*360mm metal plate with 1mm of thickness. The final equipment must be re-confirmed that it still meets EMC directives. For guidance on how to perform these EMC tests, please refer to “EMI testing of component power supplies.” (as available on https://www.meanwell.com//Upload/PDF/EMI_statement_en.pdf)

Technical drawings

LOP-300-12 LOP-300 series — LOP-300 series

LOP-300-12 LOP-300 series (2) — LOP-300 series (2)

LOP-300-12 Derating Curve — Derating Curve

LOP-300-12 Output Derating VS Input Voltage — Output Derating VS Input Voltage

Typical applications

Industrial automation machinery/ control system
Security system
Mechanical and electrical equipment
Electronic instruments, equipments or apparatus
Network equipment
Telecom devices
Power sourcing equipment of PoE
Home automation
Medical devices

Downloads

Datasheet1

LOP-300-12 datasheetLOP_300_spec.pdf · 2026-09-02 edition PDF Download

FAQ

What are the key output specs of the Mean Well LOP-300-12?

The LOP-300-12 is a 300W open frame AC/DC power supply with a 12V output, rated 15A (180W) with free-air convection or 25A (300W) with a 10.98CFM fan. It is built in a compact 4 x 2 inch form factor with a 25.4mm low-profile height. The unit also supports up to 150% peak load (450W) for 3 seconds.

What kinds of applications is the LOP-300-12 designed for?

This model is intended for space-constrained embedded power applications that need a compact open frame supply with high power density. Its certifications span ITE, medical, household, and industrial standards, which makes it suitable for use across multiple equipment categories. It is especially relevant where a 12V output and low-profile design are important.

Is the Mean Well LOP-300-12 suitable for medical equipment?

Yes, the LOP-300-12 includes IEC60601-1 and ANSI/AAMI ES60601-1 medical safety approvals. It also offers 2 x MOPP primary-to-secondary isolation and touch current below 100μA (Class II) at 264VAC. Buyers should still confirm the full system-level compliance requirements for their end product.

How does the LOP-300-12 perform in high-temperature environments?

The power supply is rated for operation from -40°C to +80°C, subject to the manufacturer's derating curve. That wide temperature range makes it a strong option for demanding environments. It also includes over-temperature protection that shuts down output voltage until conditions return to a safe range.

Does the LOP-300-12 support universal AC input?

Yes, this model accepts a wide input range of 80 to 264VAC, and it also supports 113 to 370VDC. It includes active power factor correction, with power factor specified above 0.95 at 230VAC and above 0.98 at 115VAC at full load. This makes it suitable for global equipment designs that need broad input compatibility.

What protections are built into the Mean Well LOP-300-12?

The LOP-300-12 includes overload, over-voltage, and over-temperature protection. Its overload protection operates in hiccup mode after 3 seconds and recovers automatically once the fault is removed. Over-voltage protection (13.2 to 15.6V) shuts down the output, and the unit must be re-powered to recover.

What distinguishes the LOP-300-12 from larger enclosed power supplies?

The main differentiator is its compact 4 x 2 inch open frame format with a low 25.4mm profile, which helps in tight internal layouts. It also delivers 92.5% typical efficiency and can reach 300W with 10.98CFM forced-air cooling. Compared with bulkier enclosed units, it is better suited to designs where board space and height are limited.

What physical size and weight does the LOP-300-12 offer?

Its dimensions are 101.6 x 50.8 x 25.4 mm, and the listed weight is 0.21 kg. These details make it easier to evaluate for compact equipment designs with strict space and weight constraints.

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Model	Power	Voltage	Current
Mean Well LOP-300-54 300W 4"×2" Low Profile Open Frame Power Supply 54V 3.4A	183.6W	54V	3.4A	View
Mean Well LOP-300-48 300W 4"×2" Low Profile Open Frame Power Supply 48V 3.8A	182.4W	48V	3.8A	View
Mean Well LOP-300-36 300W 4"×2" Low Profile Open Frame Power Supply 36V 5A	180W	36V	5A	View
Mean Well LOP-300-30 300W 4"×2" Low Profile Open Frame Power Supply 27V 6A	180W	30V	6A	View
Mean Well LOP-300-27 300W 4"×2" Low Profile Open Frame Power Supply 27V 6.7A	180.9W	27V	6.7A	View
Mean Well LOP-300-24 300W 4"×2" Low Profile Open Frame Power Supply 24V 7.5A	180W	24V	7.5A	View
Mean Well LOP-300-18 300W 4"×2" Low Profile Open Frame Power Supply 18V 10A	180W	18V	10A	View
Mean Well LOP-300-15 300W 4"×2" Low Profile Open Frame Power Supply 15V 12A	180W	15V	12A	View

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