Power Supply Unit Synology PSU 250W_5

The Synology PSU 250W_5 is a dedicated power supply unit designed for use with Synology NAS and storage server models. Delivering a continuous 250W output, this silver-finished PSU uses non-modular cabling and an integrated active cooling fan to maintain stable power delivery in compact rack or desktop installations. Its compact physical size (155 mm × 81 mm × 41 mm) makes it compatible with a range of Synology devices and helps preserve internal space while providing the rated power for reliable system operation.

Advantages

The PSU 250W_5 provides a fixed 250W power output intended to match the requirements of compatible Synology models. Non-modular cabling reduces internal connection complexity and ensures secure fixed wiring. Built-in active cooling supports thermal stability under sustained load, and the unit’s compact dimensions simplify installation in constrained chassis. Designed by Synology, the PSU is supplied with the manufacturer part number PSU 250W_5 to facilitate correct replacement and compatibility verification.

Suitable for

• Replacement power supply for Synology RS1221+ series
• Use in Synology DS1821+ and DS1819+ storage servers
• Small office and home NAS setups that require a 250W PSU
• Environments where a compact, manufacturer-compatible PSU is required

Key specifications

• Brand: SYNOLOGY
• Manufacturer part number (MPN): PSU 250W_5
• Output power: 250W (continuous)
• Cabling: Non-modular (fixed cables)
• Cooling: Active fan cooling
• Compatible models: RS1221+, DS1821+, DS1819+
• Dimensions (W × D × H): 155 mm × 81 mm × 41 mm
• Colour: Silver

How to use

Power off the NAS or server and disconnect all external power and network connections before replacing the PSU. Remove the service panel or drive tray as described in the Synology device manual, then disconnect the existing power cable connectors from the system board and drive power headers. Install the Synology PSU 250W_5 in the original PSU bay, secure it with the appropriate screws, and reconnect the fixed cabling to the matching connectors. Replace any panels and reconnect external power, then power on the device and verify normal boot and power status indicators. Consult the Synology hardware guide for model-specific disassembly and safety instructions.

Recommendations

Use the PSU 250W_5 only with supported Synology models listed by the manufacturer. Ensure proper ventilation around the device to maintain the PSU fan’s cooling effectiveness and avoid obstructing airflow. Replace the PSU with an identical Synology part number to preserve warranty and compatibility. If you encounter abnormal noise, overheating, or power instability after installation, power down the system and contact Synology support or an authorized technician.