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be quiet! System Power 9, 400W CM, 200 - 240 V, 50 Hz, 4 A, Power Supply Unit
be quiet! System Power 9, 400W CM, 200 - 240 V, 50 Hz, 4 A, Power Supply Unit
be quiet! System Power 9, 400W CM, 200 - 240 V, 50 Hz, 4 A, Power Supply Unit
be quiet! System Power 9, 400W CM, 200 - 240 V, 50 Hz, 4 A, Power Supply Unit
be quiet! System Power 9, 400W CM, 200 - 240 V, 50 Hz, 4 A, Power Supply Unit
be quiet! System Power 9 400W noise level chart showing dB(A) at 20, 50, and 100% load
BeQuiet System Power 9 400W cable layout diagram with SATA, PCIe, and 24-pin ATX lengths
RoHS 2002/95/EC compliance badge for be quiet! System Power 9 400W power supply unit
Be Quiet System Power 9 400W PSU Energy Star certified efficiency badge
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be quiet! System Power 9, 400W CM, 200 - 240 V, 50 Hz, 4 A, Power Supply Unit

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Product Code: PSEL-046

MPN #: BN300

Tired of noisy, unreliable power units that waste electricity and raise your bills? The Power Supply you need is the be quiet! System Power 9, 400W CM, 200 - 240 V, 50 Hz, 4 A, Power Supply Unit - a quiet, efficient source that keeps your PC running smoothly without breaking the bank.

Usages of a 400W Power Supply

Ideal for budget-friendly desktops, office workstations and entry-level gaming rigs, this Power Supply delivers stable power for everyday tasks, light multitasking and occasional graphics-intensive sessions, fitting neatly into compact cases.

Benefits of be quiet! Power Supply
  • Quiet operation: low-noise fan design lets you work or game without distraction.
  • Energy efficiency: 80 PLUS Bronze rating reduces electricity costs.
  • Semi-modular cables: only connect what you need for a tidy build.
  • Reliable protection: built-in safeguards guard components from spikes.
  • Compact size: fits small cases while delivering full 400 W.

be quiet! Power Supply

Choosing this Power Supply means you get a blend of quiet performance and solid efficiency that many cheaper units lack. Its 400 W output is enough for most mainstream builds, and the semi-modular layout helps you keep cables organised, improving airflow and system longevity. With a three-year warranty, you also gain peace of mind that the unit will stand the test of time.

Key Features of a 400W Power Supply
  • Form factor: ATX. Fits standard cases and mounting points.
  • Colour: Black. Matches most PC aesthetics.
  • Efficiency rating: 80 PLUS Bronze Certified. Saves power and lowers heat.
  • Total power: 400 W. Provides ample juice for mid-range builds.
  • SATA connectors: 5. Supports multiple drives and SSDs.
  • PCIe connectors: 2 × 6+2-pin. Powers entry-level graphics cards.
  • CPU connector: 1 × 4+4-pin EPS. Supplies stable power to the processor.
  • Dimensions (W × D × H): 150 mm × 140 mm × 86 mm. Fits tight spaces easily.
  • Warranty: 3 Years. Guarantees long-term reliability.
  • Modular design: Semi-modular. Reduces clutter and improves airflow.

Specifications
General  
Product Name Be Quiet! BN300
Type Power Supply Unit
Purpose PC
Condition New
Form Factor ATX Power Supply Unit
PSU Form Factor ATX
Product Colour Black
Main Colour Black
Modular Cables Semi-Modular
Create Your Own Gaming PC (CCL) Yes
Compliance  
Standards 80 PLUS Bronze Certified
80Plus Rated 80 Plus Bronze
Electrical  
Total Power 400 W
Interfaces / Ports  
SATA Connectors 5
CPU Connectors 1 x 4+4-pin EPS
Motherboard Connectors 1 x 20+4-pin ATX
PCI Connectors 2 x 6+2-pin PCIe
Molex (PATA) Connectors 2
PCIe Connectors 2
PCIe Pin Type 6+2-Pin
CPU Power Pins (Male) 8
PCIe Power Pins (Male) 16
Motherboard (EPS) Power Connectors 4+4-Pin
Physical  
Case Colour Black
Width 150 mm
Depth 140 mm
Height 86 mm
PSU Depth 140 mm
Warranty  
Warranty 3 Years
Item Details  
Manufacturer Be Quiet!
Manufacturer Code BN300
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