P38995-B21 - HPE 800W Flex Slot Platinum Hot Plug Low Halogen Power Supply Kit

HPE P38995-B21 — Flex Slot Platinum 800W Power Supply (Hot-Plug)

What it is

P38995-B21 is an HPE Flex Slot Platinum power supply unit used in ProLiant servers with Flex Slot PSU bays (for example DL360/DL380 Gen10 and similar). It provides 800 W of output with high efficiency and hot-plug capability, letting you replace or add PSU capacity without powering the server down (when redundancy permits).

Why buyers pick P38995-B21 (plain English)

• Reliable enterprise power
  Platinum-rated efficiency means less waste, lower heat, and stable power delivery for critical servers.

• Hot-plug serviceability
  Can be swapped or added without shutting down the server — great for maintenance windows and redundancy builds.

• Redundancy support
  When installed with a second PSU, enables N+1 power resiliency for production systems.

• OEM-qualified part
  HPE-branded, firmware-aware PSU that reads correctly in iLO power reporting and health monitoring.

60-second spec box (P38995-B21)

Type

• Flex Slot Platinum Hot-Plug Power Supply

Output power

• 800 W

Efficiency rating

• Platinum (high-efficiency class)

Input

• Auto-ranging AC input (typically ~100–240 V AC)

Hot-swap support

• Yes (in supported systems with multiple PSUs)

Form factor / compatibility

• Flex Slot PSU architecture

• Commonly fits ProLiant DL360 / DL380 Gen10 / Gen10+ and other Flex Slot–capable servers

Redundancy

• Supports 1+1 redundant PSU configurations when two units are present

Monitoring

• Power/health reporting via iLO / system firmware

Where it fits (and when to choose something else)

Perfect for:

• Replacing a failed PSU in an HPE server with Flex Slot slots

• Adding a second PSU for redundant power in production racks

• Upgrading to a Platinum efficiency unit from Bronze/Silver

Choose something else if:

• You need different wattage (e.g., 500 W or 1600 W) → match PSU to system draw

• Your server uses non-Flex Slot PSUs → use the specific PSU for that chassis family

TL;DR

P38995-B21 is an 800 W HPE Flex Slot Platinum hot-plug power supply — a server PSU used in ProLiant Flex Slot systems for reliable, efficient, and redundant power delivery.

HPE 800W Flex Slot Platinum Hot Plug Low Halogen Power Supply Kit

How do you improve data center power efficiency without impacting IT performance? HPE Flexible Slot Power Supplies deliver up to 96% power efficiency with 80 Plus Titanium-certified options that lower server power requirements, reduce power waste and costs in your data center, and simplify your spares strategy ¹ . Its form factor is 25% smaller than previous generations leaving more space to add server options improving the performance of your servers.  Fast, tool-less hot-plug access simplifies and enhances serviceability. Support HPE ProLiant Gen10, Gen10 Plus, and Gen11 servers, select HPE Apollo Gen10 & Gen10 Plus systems, and HPE Alletra 4100 data storage servers, simplifying your spares strategy and further reducing data center costs.