CUS400M-12/A

AC/DC Open Frame Power Supply (PSU), ITE & Medical, 1 Output, 400W, 250 W, 85V AC to 264V AC

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Manufacturer: TDK-LAMBDA
Product type: AC / DC Open Frame Power Supplies
SVHC: No SVHC (15-Jan-2018)
Product Range: CUS400M Series
No. of Outputs: 1 Output
Input Voltage VAC: 85V AC to 264V AC
Power Supply Output Type: Adjustable, Fixed
Output Current - Output 1: 20.83A
Output Current - Output 2: -
Output Current - Output 3: -
Output Current - Output 4: -
Output Voltage - Output 1: 12VDC
Output Voltage - Output 2: -
Output Voltage - Output 3: -
Output Voltage - Output 4: -
Power Supply Applications: ITE & Medical
Power Rating (Forced Cooling): 400W
Power Rating (Convection Cooling): 250W

Delivery and price
Units per pack	10
Price	130.12 €
Current stock	10+
Lead time	30 days

Datasheet

CUS400M Series 

3 x 5” 400W AC-DC Power Supplies 

https://product.tdk.com/en/power/cus-m www.emea.lambda.tdk.com/cus400m 

The compact CUS400M is packaged in the industry standard 3x5” footprint.  The series can deliver 400W with forced air or 250W when convection cooled with a 400W peak power for extended periods of time (minutes). Cooling is also assisted via conduction through the base into the equipment chassis. With Medical & ITE certifications, the units can be used in both Class I & Class II (no ground wire) applications, and meets Class B Conducted and Radiated EMI. Options include a standby voltage, signals and multiple case options. 

|**Features**|**Benefits**|
|---|---|
|• 250W Convection / Conduction Cooled with 400W Peak for Extended Time Periods|• Quiet Operation|
|• 400W with Forced Air|• Can Utilise System Airflow or Integrated Fan|
|• Medical Certifications (2 x MOPP)|• Suitable for B and BF Type Medical Equipment|
|• Class B Conducted and Radiated EMI|• Easier System EMC Compliance|
|• Suitable for Class I and Class II installations|• Flexible Utilisation|
|• Compact 3 x 5 x 1.55” Size|• Space Saving in End Equipment|
|• Enclosure & Signal Options|• Versatile Application|



|**Model Selector**|**Model Selector**|||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
||Nominal|||Output|||Maximum||Maximum|||Maximum||||Peak Current (A)|||||Maximum||||Maximum|
|Model|Output||Adjustment|||||Current||||Current|Convection cooled ≥115Vac input||||Convection cooled ≥115Vac input|||||Power|Power||Power|
||Voltage (V)||||(V)||Convection (A)|||||Forced Air (A)||(See derating curve section)||(See derating curve section)||||Convection (W) Forced Air (W)||||||
|CUS400M-12|12||12 - 13.2||12 - 13.2|||20.83||||33.33|||||33.33|||||250|||400|
|CUS400M-15|15||15 - 16.5||15 - 16.5|||16.67||||26.67|||||26.67|||||250|||400|
|CUS400M-19|19||19 - 20.9||19 - 20.9|||13.16||||21.05|||||21.05|||||250|||400|
|CUS400M-24|24||24 - 26.4||24 - 26.4|||10.42||||16.67|||||16.67|||||250|||400|
|CUS400M-28|28||28 - 30.8||28 - 30.8|||8.93||||14.29|||||14.29|||||250|||400|
|CUS400M-36|36||36 - 39.6||36 - 39.6|||6.94||||11.11|||||11.11|||||250|||400|
|CUS400M-48|48||48 - 49.9||48 - 49.9|||5.21||||8.33|||||8.33|||||250|||400|
|||||||||||||||||||||||||||
|**CUS400M-**|**CUS400M-**<br>**12**|||**/**|**/**<br>**U**|||||**M**|||||||**E**|||**X5**||**X5**|**-**|||
|||||||||||||||||||||||||||
|Output voltage 12, 15, 19, 24, 28, 36, 48|Output voltage 12, 15, 19, 24, 28, 36, 48||||||||||||||blank<br>E||dual fuses<br>single input fuse in|||||blank Standard leakage|blank Standard leakage<br>current (<250uA)|||
|blank open frame with plastic baseplate<br>C open frame with plastic baseplate|blank open frame with plastic baseplate<br>C open frame with plastic baseplate<br>and M3 threaded inserts for under|||||||Blank JST Connectors|Blank JST Connectors||||||||line (AC input only)|||||R|Reduced leakage<br>current  <150uA<br>(Contact Technical Sales)|||
||side mounting|||||||M|Molex type input connector|||||||||||||||||
|U U channel chassis|U U channel chassis|||||||||||||||||||||||||
|B open frame with metal baseplate|B open frame with metal baseplate|B open frame with metal baseplate||||||||||||||||||||||||
|A U channel chassis with cover|A U channel chassis with cover|||||||||blank No options|||blank No options|||||||||||||
|F U channel chassis, cover and|F U channel chassis, cover and<br>top fan||||F U channel chassis, cover and|||||X2<br>X3||X2<br>5V 2.0A standby supply, remote on/off (enable), remote sense, DC-OK, AC Fail<br>X3<br>12V 0.83A standby supply, remote on/off (enable), remote sense, DC-OK, AC Fail||||||||||||||
|||||||||||X5||X5<br>5V 2.0A standby supply, remote on/off (inhibit), remote sense, DC-OK, AC Fail||||||||||||||
|||||||||||X6||X6<br>12V 0.83A standby supply, remote on/off (inhibit), remote sense, DC-OK, AC Fail|12V 0.83A standby supply, remote on/off (inhibit), remote sense, DC-OK, AC Fail|||12V 0.83A standby supply, remote on/off (inhibit), remote sense, DC-OK, AC Fail||||||||||



Example: CUS400M-15V25/FEX5 = 15.25V factory output voltage set point, U chassis, cover and fan, single fuse, X5 standby and signals 

CUS400M Series 

1 

**==> picture [516 x 34] intentionally omitted <==**

|**Specifcations**|**Specifcations**|**Specifcations**|
|---|---|---|
|Model<br>CUS400M|||
|**Input**|||
|Input Voltage Range (Operating)|Vac|85 - 264 (Derate output by 1% / 1Vac below 115Vac input)<br>|
|Nominal Input Voltage Range|Vac|100 - 240 (Note: Safety certifed for 90-264Vac)<br>|
|Input Frequency|Hz|47 - 440 (Certifed to the 62368-1 standard only)|
|Input Current (100Vac)|A|< 5.0|
|Inrush Current at 264Vac, 63Hz (Cold Start)|A|<40|
|Leakage Current (1)|uA|<250|
|Touch Current (Enclosure Leakage)(1)|uA|<100|
|Power Factor (100Vac, 47-63Hz)(2)|-|> 0.97 (>20% load)|
|Harmonic Compliance (50-60Hz)|-|IEC61000-3-2 Class A|
|No Load Power Consumption|W|<1.3 when output is inhibited (230Vac input).  <10 without output inhibited|
|Hold Up Time at 115Vac Input<br>|ms|>16 (400W load) (CUS400M-15 >12ms)|
|Effciency<br>|%|Up to 94|
|Average Effciency|%|>87. Measured at 25%, 50%, 75% and 100% load conditions|
|Conducted & Radiated EMI|-|EN55032/EN55011-B (See application notes for conditions)|
|Immunity|-|Compliant with EN60601-1-2;2015 (Edition 4), see immunity table|
|Insulation Class<br>|-|Construction suitable for Class I or Class II installation|
|Safety Certifcations and Markings|-|IEC/EN/UL/CSA62368-1, 60950-1, IEC/EN60601-1, ES60601-1, CE Mark and UKCA Mark|



## **Immunity** 

|**Immunity**|**Immunity**|**Immunity**|**Immunity**|**Immunity**|
|---|---|---|---|---|
||||||
|Test|Standard|Test Level|Criteria|Notes (the power stated below is total power (main power + fan output))|
|ESD|IEC61000-4-2|3|A|-<br>|
|Radiated Susceptibility|IEC61000-4-3|3|A|Includes proximity feld requirements of IEC60601-1-2:2015|
|Electrical Fast Transient Burst|IEC61000-4-4|4|A|(AC Port, 5kHz and 100kHz)|
|Surge|IEC61000-4-5|3|A|-|
|Conducted Susceptibility<br>|IEC61000-4-6|3|A|-|
|Magnetic felds|IEC61000-4-8|4|A|-|
|Voltage Dips and<br>Input Interruptions|IEC61000-4-11<br>Class 3 Industrial,<br>incl EN55024|0% for 1/2 cycle<br>0% for 1 cycle<br>40% for 10/12 cycles<br>70% for 25/30 cycles<br>80% for 250/300 cycles<br>0% for 250/300 cycles|A<br>A/B<br>A/B<br>A/B<br> <br>A/B<br>B|-<br>A up to 290W, B above 290W<br>A up to 100W, B above 100W<br>A up to 250W, B above 250W<br>A up to 270W, B above 270W<br>-|
||IEC60601-1-2:2015|0% for 1/2 cycle<br> <br>0% for 1 cycle<br>70% for 25/30 cycles<br>0% for 250/300 cycles|A<br>A/B<br>A/B<br>B|Customer to consider essential performance of end equipment<br>A up to 290W, B above 290W<br>A up to 250W, B above 250W<br>-|
||IEC61000-6-2|0% for 1 cycle<br>40% for 10/12 cycles<br>70% for 25/30 cycles<br>0% for 250/300 cycles|B<br>C<br>C<br>C|-<br>-<br>-<br>-|
||IEC61204-3|0% for 1/2 cycle<br>0% for 1 cycle<br>70% for 25/30 cycles<br>0% for 250/300 cycles|B<br>B<br>C<br>C|-<br>-<br>-<br>-|
|Ringwave Test|IEC61000-4-12|3|A|-|
|Voltage Fluctuations|IEC61000-4-14|Class 3|A|-|



Notes: 

(1) Applies to standard leakage version, 47-63Hz. 

(2) Power factor is degraded at input frequencies above 63Hz See website for detailed specifications, test methods and installation manual Specification parameters apply at 25°C ambient temperature unless otherwise stated. 

CUS400M Series 

2 

**==> picture [516 x 34] intentionally omitted <==**

|**Specifcations**|**Specifcations**|**Specifcations**|
|---|---|---|
|Model<br>CUS400M|||
|**Output**|||
|Line Regulation|%|0.5 (85 - 264Vac)|
|Load Regulation|%|1.0 (0 - 100% load)|
|Ripple & Noise<br>|%|<1|
|Temperature Coeffcient|%/°C|±0.02|
|Minimum Load|-|No minimum load required|
|Overcurrent Protection|%|101 to 170. Hiccup mode, automatic recovery|
|Overvoltage Protection|-|Latching (unit shutdown), cycle AC input to reset|
|Overtemperature Protection|-|Latching (unit shutdown), cycle AC input to reset|
|Remote Sense|-|See model selector (requires X option) 0.5V total compensation<br>Voltage at output terminals must remain within the range specifed in the model selector|
|Remote On/Off|-|Opto-isolated. Inhibit: High = OFF, Low = ON, Enable: High = ON, Low = OFF|
|DC Good|-|Opto isolated, >20ms after output good|
|AC Fail|-|Opto isolated, 5ms warning before DC loss|
|Fan Supply|-|7 to 13.2V, 0.3A. (Variable with main output load, see application notes)|
|Parallel Operation|-|Not possible|
|Series Operation|-|Please contact Technical Sales for guidance|
|**Environmental**|||
|Operating Temperature (-30°C start-up)|°C|-20°C to +70°C, derate linearly above 50°C to 50% load|
|Storage Temperature|°C|-40°C to +85°C (70°C maximum for fan version /F)|
|Operating Humidity (non condensing)|%RH|5 - 95%RH (15 - 90%RH for /F fan version)|
|Cooling|-|Convection cooling or forced air (0.3m/s required for 400W output at 115Vac input)|
|Altitude|m|5,000m. Operating, transportation and storage|
|Withstand Voltage (For 1 minute)|Vac|Input to Ground 1.5kVAC (1xMOPP), Input to Output 4kVAC (2xMOPP),<br>Output to Ground 1.5kVAC (1xMOPP)|
|Isolation Resistance|MΩ|>100MΩ at 25°C & 500Vdc|
|Vibration (Operating)|-|2G, 10-200Hz for 1 hour. Conforms to EN60068-2-6, IEC68-2-6, MIL-STD-810G|
|Shock|-|30G, 11ms half sine. Conforms to EN60068-2-27, EN60068-2-47, IEC68-2-27, IEC68-2-47, MIL-STD-810G|
|**Other**|||
|Weight (max)|g|440g (open frame version with plastic baseplate), /B: 495g, /C: 445g, /U: 530g, /A: 550g, /F: 605g|
|Size (WxLxH)|mm<br>in|Open frame version with plastic baseplate: 128 x 77.5 x 39.5<br>Open frame version with plastic baseplate:  5 x 3 x 1.55|
|Connectors|-|Input: JST VAR-2, Output: M4 screws, Fan: Molex 51191-0200, Signals: Molex 51110-1051|
|Warranty|yrs|5|



## Notes: 

(1) Applies to standard leakage version See website for detailed specifications, test methods and installation manual Specification parameters apply at 25°C ambient temperature unless otherwise stated. 

CUS400M Series 

3 

## **Peak Power Rating Curves.** U chassis configuration, convection cooled on metal baseplate 

|Ambient|AC Line Input|Maximum ON time|Maximum|Maximum achievable|
|---|---|---|---|---|
|Temperature (°C)|(Vrms)|(minutes)|Duty Cycle (%)|output power|
|30|85|18|47|250W peak power|
|30|115|5|38|400W peak power|
|30|230|oo|100|400W Continuous|
|40|230|30|50|400W peak power|
|50|85|0|0|No peak rating|
|50|115|1|8|400W peak power|
|50|230|10|50|400W peak power|



The curves below are guidelines only. The actual performance should be tested in the application. 

See application notes for all mechanical formats. 

## **Output Power vs Ambient Temperature   Open Frame Unit (mounted on a 300 x 300 x 1 mm aluminum plate)** 

CUS400M Series 

4 

**==> picture [462 x 230] intentionally omitted <==**

**----- Start of picture text -----**<br>
Electrolytic Capacitor Life ( CUS400M-12 Open Frame Unit Convection and Conduction Cooled)<br>115Vac Convection+ Conduction<br>20<br>i 15 — — + $—_—_<br>2 ae a +— 20°C<br>10 a AX - a 30°C<br>—<<br>3<br>25% 5076 75% 100%<br>Load {250W}<br>Efficiency (CUS400M-24)<br>**----- End of picture text -----**<br>


CUS400M Series 

5 

## **Mechanical Specification** 

## **Outline Drawing CUS400M Open Frame Unit** 

## **MATING CONNECTORS AND PINS** 

CUS400M Series 

6 

## **Mechanical Specification** 

## **Outline Drawing CUS400M Open Frame Unit with Baseplate** 

CUS400M Series 

7 

## **Mechanical Specification** 

## **Outline Drawing CUS400M/U (U Channel) Option** 

CUS400M Series 

8 

## **Mechanical Specification** 

**Outline Drawing CUS400M/A (U Channel with Cover) Option** 

CUS400M Series 

9 

## **Mechanical Specification** 

## **Outline Drawing CUS400M/F (U Channel, Cover and Fan) Option** 

CUS400M Series 

10 

## **TDK-Lambda France SAS** 

Tel: +33 1 60 12 71 65 tlf.fr-powersolutions@tdk.com www.emea.lambda.tdk.com/fr 

## **TDK-Lambda Americas** 

Tel:  +1 800-LAMBDA-4 or 1-800-526-2324 tla.powersolutions@tdk.com www.us.lambda.tdk.com 

## **Italy Sales Office** 

Tel +39 02 61 29 38 63 tlf.it-powersolutions@tdk.com www.emea.lambda.tdk.com/it 

## **TDK Electronics do Brasil Ltda** 

Tel: +55 11 3289-9599 sales.br@tdk-electronics.tdk.com www.tdk-electronics.tdk.com/en 

## **Netherlands** 

tlf.nl-powersolutions@tdk.com www.emea.lambda.tdk.com/nl 

## **TDK-Lambda Corporation** 

Tel: +81-3-6778-1113 www.jp.lambda.tdk.com 

## **TDK-Lambda Europe GmbH** 

Tel: +49 7841 666 0 tlg.powersolutions@tdk.com www.emea.lambda.tdk.com/de 

## **TDK-Lambda (China) Electronics Co. Ltd.** 

Tel: +86 21 6485-0777 tlc.powersolutions@tdk.com 

www.lambda.tdk.com.cn 

nm ~~=~~ **Austria Sales Office** = **TDK-Lambda Singapore Pte Ltd.** Tel: +43 2256 655 84 Tel: +65 6251 7211 tlg.at-powersolutions@tdk.com tls.marketing@tdk.com www.emea.lambda.tdk.com/at www.sg.lambda.tdk.com ~~a~~ **Switzerland Sales Office** = **TDK India Private Limited, Power Supply Division** ~~c~~ Tel:tlg.ch-powersolutions@tdk.com+41 44 850 53 53 Tel:   +91 80 4039-0660mathew.philip@tdk.commathew.philip@tdk.com www.emea.lambda.tdk.com/ch 

Tel:   +91 80 4039-0660mathew.philip@tdk.commathew.philip@tdk.com www.sg.lambda.tdk.com 

## **TDK-Lambda Europe GmbH** 

Tel: Tel. +45 3222 8086 tlg.dk-powersolutions@tdk.com www.emea.lambda.tdk.com/dk 

## **TDK-Lambda UK Ltd.** 

Tel: +44 (0) 12 71 85 66 66 tlu.powersolutions@tdk.com www.emea.lambda.tdk.com/uk 

## **TDK-Lambda Ltd.** 

Tel: +9 723 902 4333 tli.powersolutions@tdk.com www.emea.lambda.tdk.com/il-en 

For additional information, please visit https://product.tdk.com/en/power/ 

CUS400M_260649 August18th, 2025 V11 

CUS400M Series 

11

Updated at April 27, 2026

TDK-Lambda is globally recognized as a premier manufacturer of highly reliable power supply solutions and power management equipment. With a strong engineering heritage, the company is a trusted partner for mission-critical applications across the industrial, medical, telecommunications, and test and measurement sectors, delivering components that meet stringent international performance and safety standards. Our extensive portfolio of TDK-Lambda products is heavily focused on comprehensive power and line protection, highlighted by a vast selection of industry-leading AC/DC converters. Engineered to deliver exceptional efficiency and stable performance in demanding environments, these power supplies form the backbone of our offering and are built to support the rigorous power demands of modern electronic infrastructure. To complement these primary power solutions, we also offer a targeted range of high-performance DC/DC converters designed for precise, board-level voltage regulation. Furthermore, to ensure the optimal performance and longevity of these power systems, our catalog includes specialized cooling and thermal management components, such as natural convection heat sinks, providing complete thermal stability for your most critical designs.

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