865399-501 is the HPE alternate part number for 500W Flex Slot Platinum Hot Plug Low Halogen Power Supply Kit. It is a hot-plug, redundant plug-in module built to the HPE Flex Slot specification, delivering 500 watts from a 100-240V AC input at 50-60 Hz through an IEC 60320 C14 connector. Rated 80 PLUS Platinum at 94% efficiency, it fits DL360 Gen10, DL380 Gen10 and ML350 Gen10 servers as a primary or second supply for redundancy. The module measures 2.7 in wide, 8.9 in deep and 1.6 in high, weighs 32.1 oz, and is low halogen for builds with restricted-materials requirements.
HPE Option Part #: 865408-B21
HPE Spare Part #: 866729-001
HPE Model #: 865398-001
HPE Assembly Part #: 865399-101
PRODUCT SPECIFICATIONS FOR 865399-501:
- Product Type: Power supply - hot-plug / redundant
- Form Factor: Plug-in module
- Specification Compliance: Flex Slot
- Power Supply Compatibility: PC/Server
- Power Provided: 500 watt
- Power Capacity (VA): 563 volt ampere per kilogram
- Voltage Required: AC 100-240 volt
- Frequency Required: 50 - 60 hertz
- Input Connector Type: Power IEC 60320 C14
- Efficiency: 94%
- 80 PLUS Certification: 80 PLUS Platinum
- Compliant Standards: BSMI, CCC, CISPR Class A, C-Tick, cUL, KCC, Low halogen, TUV, UL, WEEE
- Width: 2.7 inch
- Depth: 8.9 inch
- Height: 1.6 inch
- Weight: 32.1 ounce
- Min Operating Temperature: 41 degree Fahrenheit
- Max Operating Temperature: 131 degree Fahrenheit
- Humidity Range Operating: 5 - 95% (non-condensing
COMPATIBLE WITH:
PROLIANT DL SERIES
PROLIANT ML SERIES
** This list may not be complete. Contact us via Live Chat if you have any questions about compatibility.
FREQUENTLY ASKED QUESTIONS ABOUT 865399-501
What is the difference between 865399-501, 865408-B21 and 866729-001?
All three identify the same physical 500W Flex Slot Platinum power supply. This page, 865399-501, is an alternate part number. 865408-B21 is the option part number, the configurable kit ordered for new or expanding systems. 866729-001 is the spare part number used for service replacement. The family also includes one assembly revision and one OEM model number, both listed in the cross-reference block on this page. An assembly part number identifies a specific build revision of the unit, and an OEM model number is the manufacturer's own internal designation.
Which servers does this power supply support?
This 500W Flex Slot module is listed for the HPE ProLiant DL360 Gen10, DL380 Gen10 and ML350 Gen10. It installs in a Flex Slot power supply bay as a plug-in module and supports hot-plug operation, so a second unit can be added for redundancy in a supported chassis. Confirm the total wattage required by your processor, memory, drive and option configuration before selecting a 500W supply.
What are the electrical input requirements?
The unit accepts AC 100-240 volts at 50-60 Hz and uses a Power IEC 60320 C14 input connector, so it works with standard rack PDU C13 cords. Output is 500 watts, with a stated power capacity of 563 VA. Efficiency is 94% and the supply carries 80 PLUS Platinum certification, which reduces heat rejection and input draw compared with lower-efficiency supplies at the same load.
What are the physical and environmental specifications?
The module is 2.7 inches wide, 8.9 inches deep and 1.6 inches high, and weighs 32.1 ounces. Operating temperature range is 41 to 131 degrees Fahrenheit with operating humidity of 5 to 95 percent non-condensing. Compliance covers BSMI, CCC, CISPR Class A, C-Tick, cUL, KCC, TUV, UL and WEEE, and the unit is low halogen for environments with restricted-materials specifications.
Last Updated: 2026-09-01
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This product is warrantied against hardware failure for a period of 1 Year from the date of purchase. Before making a purchase, please take a moment to review our return policy below.
Returns
It is the customer's responsibility to verify compatibility with their machine(s) before placing an order. If an item is ordered by mistake, it can be returned for refund, minus a 25% restocking fee, within 5 business days of receipt. The cost of freight is not refundable.
Please be aware that factory-sealed equipment can only be returned if it remains unopened.
Defective Products
If you have received a defective part and your machine is still within the HPE warranty period, please initiate a warranty exchange by visiting the HPE Enterprise Support Center. Be sure to have the serial numbers of the defective drive and your server/storage array handy.
In case your hardware becomes defective during the Global One warranty period, but the HPE warranty has expired, you can return the product to us for a working replacement. You are responsible for the shipment of returned merchandise. However, we will cover the expense of Ground /Economy shipment for the replacement item(s).
Requesting an RMA
To initiate a return or warranty claim, please complete and submit the RMA Request Form.


