Power Supply Unit HPE 865434-B21 800 W

The HPE 865434-B21 Power Supply Unit delivers 800 W of continuous power with 94% efficiency, designed for enterprise server environments. It uses a compact flexible slot form factor that reduces size compared with previous generation common slot supplies, enabling more room inside the chassis for additional server options. The unit is intended for hot-plug installation and is suitable for use across multiple HPE server families to simplify spare parts strategy and support high-demand workloads while maintaining energy efficiency.

Advantages

This power supply offers high conversion efficiency to reduce wasted energy and lower operating costs. Its 25% smaller flexible slot form factor frees internal space for additional components and upgrades. Tool-less, hot-plug capability improves serviceability and shortens maintenance time. Broad compatibility across HPE ProLiant Gen10, ProLiant 300 Gen9, Apollo 2000 and Apollo 4000 series helps standardize spares and reduce inventory complexity.

Suitable for

• Enterprise rack servers requiring an 800 W single power source
• Data centers seeking improved energy efficiency and reduced power waste
• Environments that need hot-plug, easily serviceable power modules

When it may not be suitable

This unit is intended for compatible HPE server platforms; it may not fit or function in non-HPE chassis or models that do not support the HPE flexible slot form factor. Systems that require higher total redundancy or greater than 800 W per supply will need different or additional power supplies.

Key specifications

• Total output power: 800 W
• Efficiency: 94% (measured under manufacturer conditions)
• Form factor: flexible slot, 25% smaller than previous common slot designs
• Installation: hot-plug, tool-less access
• Colour: grey

How to use

Install the HPE 865434-B21 into a compatible server’s flexible slot bay following the server manufacturer’s installation procedure. The unit supports hot-plug replacement, allowing you to remove and insert power supplies without powering down supported chassis. Ensure connectors are properly seated and the server firmware recognizes the supply after insertion. Follow standard safety and electrostatic discharge precautions during handling.

What to consider before purchase

• Confirm compatibility with your server model and chassis flexible slot specification
• Verify that 800 W per supply meets your system power and redundancy requirements
• Check that your data center power architecture (voltage, connectors) matches the supply

Recommendations

For reliable operation, combine the HPE 865434-B21 with compatible HPE server platforms and maintain firmware at vendor-recommended levels; monitor power and temperature in the chassis and plan redundancy according to workload criticality.