128284-B21 is an HP/Compaq hot-plug redundant fan kit designed for the ProLiant ML530 and ML570 server families. The kit adds redundant cooling capacity to maintain airflow and system operation if a standard fan fails. HP documentation lists 128284-B21 as the Hot-plug Redundant Fan Kit for the ML570, while parts references identify it for ML530 G2/ML570 G2 systems.
- Part Number: 128284-B21
- Manufacturer: HP / Compaq
- Product: Hot-Plug Redundant Fan Kit
- Fan Type: Hot-plug server cooling fans
- Redundancy: Adds redundant cooling capability
- Compatible Systems: ProLiant ML530 and ML570, including ML530 G2 / ML570 G2; also documented for the original ML570.
- Fan Configuration: 2 × additional redundant fans for the original ML570 configuration.
- Application: Server chassis cooling and fan-failure redundancy
- Hot-Plug: Yes
- Included: Redundant fan kit; fan quantity/configuration can vary by supported server generation
- Related Fan: 161657-001 — ML530/ML570 92mm hot-plug fan
- Related Parts: 122225-001, 323457-002, 171531-001 — ML530 G2/ML570 G2 hot-swap fan assemblies.
- Compatibility Note: 128284-B21 is a fan kit, not a single replacement fan. HP lists it as a redundant option for ML570, with the kit included as standard on certain rack-optimized configurations.