Power supply unit Seasonic SS-400 H1U 1U, 400 W, fully-modular, 80 PLUS, grey, 40 mm fan

The Seasonic SS-400 H1U Active PFC F0 is a 1U form-factor power supply delivering 400 W of total power with 80 PLUS efficiency (approximately 83%). Designed for compact rack installations and small-form-factor PCs, the unit accepts 100–240 V AC input at 50–60 Hz and includes a 40 mm cooling fan. The PSU features fully-modular cables and easy-swap connectors to simplify installation and cable management, and it holds CB, cUL, CCC and TUV approvals for safety and reliability.

Advantages

This Seasonic power supply provides consistent 400 W output with active PFC and 80 PLUS efficiency for improved power usage. Fully-modular cabling allows flexible wiring and cleaner builds, while the Smart and Silent Fan Control (S2FC) and a high-reliability ball-bearing 40 mm fan help reduce operating noise. The unit includes protections against short circuit, over voltage and over power, and its design requires no minimum load on the 3.3 V rail.

Suitable for

• 1U rack servers and compact server appliances
• Small-form-factor desktop PCs and industrial systems
• Environments requiring modular cabling and space-efficient power supplies

Key specifications

• Total power: 400 W
• Efficiency: approx. 83% (80 PLUS certified)
• Form factor: 1U
• Input: 100–240 V AC, 50–60 Hz
• Fan: 40 mm, ball-bearing
• Cabling: fully-modular, easy-swap connectors
• Protections: short circuit, over voltage, over power
• Approvals: CB, cUL, CCC, TUV
• Colour: Grey

How to use

Install the Seasonic SS-400 H1U into a compatible 1U chassis or compact system following the chassis manufacturer’s instructions. Connect AC mains (100–240 V) via the appropriate power inlet. Attach only the required modular cables to the PSU and route them to components to maintain airflow. Ensure connectors are fully seated and secure before powering the system. Observe standard ESD precautions when handling the unit.

Recommendations

Use this PSU in enclosures with adequate ventilation and within the specified input voltage range. Verify system power draw remains below the 400 W total capacity and allow clearance for the 40 mm fan to ensure proper cooling. Regularly inspect connectors and cables for wear and maintain compliance with local safety regulations.