# Power supply unit Seasonic SS-400 H2U 400 W, 20+4 pin ATX, 80 PLUS Gold, stainless steel

**URL:** https://aio.lv/en/product--seasonic-ss-400h2u--2077437
**Data updated:** 2026-03-20 21:18 (EET)
**Category:** Power Supplies (PSU)
**Manufacturer:** SEASONIC
**Manufacturer code:** SS-400H2U
**EAN:** 4711173870463
**Warranty:** 2 Years
**Availability:** Out of stock

## Summary description

Seasonic SS-400 H2U is a 400 W ATX power supply with a 20+4 pin motherboard connector and Active PFC. Certified 80 PLUS Gold for high efficiency, it supports AC input 100–240 V at 50–60 Hz. Compact stainless steel housing with a single 60 mm fan provides cooling. Designed for desktop PCs requiring reliable, efficient DC power delivery.

## Long description

Seasonic SS-400 H2U is a compact 400 W desktop power supply designed for standard ATX systems that require reliable and efficient DC power delivery. The unit features a 20+4 pin ATX motherboard connector, Active PFC for improved power factor, and 80 PLUS Gold certification that ensures high conversion efficiency across typical load ranges. Housed in a stainless steel chassis and cooled by a single 60 mm fan, this PSU is intended for space-constrained builds where stable power and thermal management are important.
Advantages
The Seasonic SS-400 H2U combines 80 PLUS Gold efficiency with Active PFC to reduce energy losses and improve voltage stability under varying loads. Its compact stainless steel housing provides structural durability and helps with heat dissipation, while the 60 mm fan offers targeted cooling for the internal components. The 20+4 pin ATX connector ensures compatibility with a wide range of motherboards, making the unit a practical choice for standard desktop configurations that need a reliable 400 W power source.
Suitable for
 Office and home desktop PCs with standard ATX motherboards
 Small form factor systems where chassis space is limited
 Systems requiring energy-efficient operation and lower heat generation
 PCs with modest component power demands—single GPU or integrated graphics setups
Key specifications
 Total output power: 400 W
 Motherboard connector: 20+4 pin ATX
 Efficiency certification: 80 PLUS Gold
 Input voltage range: AC 100–240 V, 50–60 Hz
 Cooling: single 60 mm fan
 Enclosure material and color: stainless steel
 Active Power Factor Correction (Active PFC) included
How to use
Install the Seasonic SS-400 H2U into a compatible ATX case, securing the unit with the mounting points provided by the chassis. Connect the 20+4 pin ATX cable to the motherboard main power socket and attach any required peripheral or drive power connectors as per your system configuration. Verify AC input is set to the correct supply and connect the AC power cord. After installation, power on the system and monitor initial operation for stable voltage and normal fan activity.
Usage recommendations
For reliable long-term operation, ensure adequate case airflow so the 60 mm fan can maintain proper thermal conditions. Use this 400 W power supply in systems with modest power draws and avoid overloading the unit near its maximum continuous output. Regularly check connections and keep dust away from the intake and exhaust areas to preserve efficiency and cooling performance.

## Specifications

### Power

| Feature | Value |
|---|---|
| Total power | 400 W |
| Combined power (+3.3V) | 130 W |
| Combined power (+12V) | 348 W |
| Max output current (+3.3V) | 20 A |
| Max output current (+12V) | 29 A |
| Max output current (+5V) | 21 A |
| Max output current (-12V) | 0.8 A |
| Max output current (+5Vsb) | 3 A |
| AC input frequency | 50 - 60 |
| AC input voltage | 100 - 240 |

### Ports & interfaces

| Feature | Value |
|---|---|
| Motherboard power connector | 20+4 pin ATX |

### Performance

| Feature | Value |
|---|---|
| Purpose | PC |
| 80 PLUS certification | 80 PLUS Gold |

### Design

| Feature | Value |
|---|---|
| Fan diameter | 60 mm |
| Number of fans | 1 fan(s) |
| Product colour | Stainless steel |

### Weight & dimensions

| Feature | Value |
|---|---|
| Height | 70 mm |
| Width | 225 mm |
| Depth | 100 mm |

## FAQ

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All SEASONIC products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized SEASONIC service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

### How can I tell if this product suits my needs?

When making a choice, we recommend paying attention to the key features: total power, motherboard power connector, 80 plus certification, fan diameter, product colour, compatibility with your devices or usage conditions, material quality, functionality, and warranty terms. These characteristics will help you determine how well the model meets your needs.

## Image

https://aio.lv/img/cache/product/2077437/64781180_large.webp