866729-001 is the HPE spare part number for 500W Flex Slot Platinum Hot Plug Low Halogen Power Supply Kit. It is the number you will find in HPE service documentation or printed on the label of the unit you are replacing, and it identifies a hot-plug, redundant Flex Slot plug-in module rated at 500 watts. The supply accepts AC 100-240V at 50-60Hz through an IEC 60320 C14 inlet, is 80 PLUS Platinum certified at 94% efficiency, and is built to low halogen requirements. It drops into Flex Slot bays in the DL360 Gen10, DL380 Gen10, and ML350 Gen10.
HPE Option Part #: 865408-B21
HPE Spare Part #: 866729-001
HPE Model #: 865398-001
HPE Assembly Part #: 865399-101
PRODUCT SPECIFICATIONS FOR 866729-001:
- 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 866729-001
What is the difference between 866729-001 and 865408-B21?
They are the same physical power supply under different HPE numbering schemes. 866729-001, the number on this page, is the spare part number used for service replacement and is what appears in service documentation and on the unit label. 865408-B21 is the option kit number used when the supply is ordered as a configurable add-on. This family also includes one assembly revision, one OEM model number, and one alternate part number, all listed in the cross-reference block on this page.
What is an assembly number and what is an OEM model number?
An assembly part number identifies a specific build or revision level of the finished unit as it comes off the manufacturing line, and is often referenced in internal build records rather than in ordering systems. An OEM model number is the manufacturer's own identifier for the product, distinct from the HPE part numbering applied to it. Both appear in the cross-reference block on this page and refer to the same 500W Flex Slot Platinum supply.
Which servers does this power supply fit?
This supply is a Flex Slot plug-in module compatible with the HPE ProLiant DL360 Gen10, DL380 Gen10, and ML350 Gen10. It installs in a Flex Slot power supply bay and supports hot-plug, redundant operation, so a failed unit can be swapped in a redundant configuration without powering the server down. Confirm the bay in your chassis is a Flex Slot bay before ordering a replacement.
What are the electrical and efficiency specifications?
The unit provides 500 watts of output with a power capacity of 563 volt amperes per kilogram. Input is AC 100-240 volt at 50 to 60 hertz through a Power IEC 60320 C14 connector. It carries 80 PLUS Platinum certification with 94% efficiency. Compliant standards include BSMI, CCC, CISPR Class A, C-Tick, cUL, KCC, low halogen, TUV, UL, and WEEE.
What are the physical dimensions and operating limits?
The module measures 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. These dimensions match the standard Flex Slot form factor, so the replacement seats in the same bay as the unit being removed.
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
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