Thread Tools
Aug 15, 2010, 07:08 PM
ancora imparo
jj604's Avatar
Thread OP

How to convert Server Power Supplies

Thought it might be useful to gather this in the one place.
The practice of converting computer SERVER power supplies to make a very high quality high power supply at low cost is attractive. It doesn’t normally require any modification to the supply but the hard part is figuring out how to trick them into turning on. Far and away the best way is to find someone who has already done it. I have put down a few references I know about and welcome additions.

This is about SERVER supplies which often have large 12V capacity and not much else; it is NOT about converting normal PC power supplies. (The ‘ground the green wire and add a load resistor’ stuff). That is covered extensively elsewhere.
UPDATE There are now available supplies for PCs that have substantial 12V rails and large (850-1200 Watt) capacity that work without any electrical conversion. If you have used one of these, suggest you start a separate thread.

Please, please. This is a REFERENCE thread. Just post a link (with comments) to other posts that show how to do it if you know of one that isn’t here.

IF YOU HAVE AN OPINION OR JUST WANT TO COMMENT OR HAVE A QUESTION ABOUT CONVERTING A PARTICULAR SUPPLY please do it somewhere else (like the original threads for example or PM me). Obviously info on sources of supply for these devices is welcome though – please post that if you know it, as well as any errors that need correcting.

Bottom Line: If you have an unknown supply you need help with, try a post in the original 12v 100A supply thread (link 2 below) which seems to have a good range of posters - or start a new one with a specific title that includes your question. That thread now has some good info on how to solve an unknown supply as well. See the first few posts. When/if you ever get it to work, then post the link to that info here to make it easier for others to find.

If you have an unknown supply and can't find the information from someone who has already solved it then this post contains the best information/links on how to establish which pins might turn it on and control the output voltage.

UPDATE: This one contains additional information that is more useful.

Hope this proves useful.

Best post on how to deal with an unknown supply

Various threads containing information on converting different supplies.

1) The original IBM Series 235 Supply which started it all.

2) A simple high quality 12Volt 100Amp Power Supply thread starts here

This is my thread on the HP PROLIANT DL580/ML570G3 which is a 12V 1300Watt supply. It's still my favourite for quality, power, small size and having a proper plug for the power cord BUT it's extremely noisy because of the two small high speed cooling fans. Most people will find its vacuum cleaner impression a PIA. Note that you have to take care to identify exactly which supply by the part number. There is a range of DL580 computers with different supplies.

3) The Compaq HP ESP114 Series 12V 55A Power Supply thread starts here

This is earlb's thread on converting these. Was popular popular and remains a good solution. Decent power but much quieter because they are bigger. Easier to obtain and cheaper as well
The attached picture shows the HP 1300 Watt and ESP114 side by side (thanks earlb). The SMALLER one is the more powerful 1300W supply.

4) Dell A570P-00 570W

5) Compaq Proliant 169286-002 750W plus

6) Sony APS-111 12V 33.3A (Used in CISCO gear). Also known as Ascom Energy Systems Galaxy D0009237

7) HP Power Supply DPS-600PB/700CB

8) hp PS-3381-1C1 PSU

9) My current recommendation is the HP model DPS-600PB series ESP135 PS that is used in ProLiant DL380 G4 Rack Servers. It is rated at 575W, or 47A at 12V. It is compact, quiet and powerful and is easily modified to slow the fan down and isolate the DC out to make a 24V supply from two of them (see below under using two supplies). There is a detailed how-to on T Jin Tech's page here and feathermerchant has them as single or dual (24V) supplies. Akshu's thread (#11 below) on a kit to convert two supplies to 24V uses these ones. They are in the bottom left hand picture below.

Using two supplies in series to get 15 or 24V at high power.

Two of the DL580/ML570G3 supplies for example will supply 2600W at 24V on a 240V supply! Here’s the thread I started on the practice of connecting two supplies in series to get 24 Volts at high current. Becoming more relevant with the growth of 1000Watt chargers.

Feathermerchant on the forums sells these already made up if you don't feel you have the knowledge to do it yourself.


These supplies were never designed to be run in series. Here's a quote from someone who knows what he is talking about. Now we know much more about the internals of these supplies, the DC isolation method (see below) is preferable if you know what you are doing.

I must admit, I am more than a little concerned these days about folks connecting different power supplies in series without a full understanding of the dangers. High powered chargers demand more power, and to get it many people having heard of this practice are haphazardly connecting power supplies in configurations for which they were not designed for and have not been tested or CE certified.

All we can do is fight the good fight and continue to educate people. Every week now I get a call or two with a story about series connecting two random, disparate power supplies in an attempt to get more power - with varying success. I sincerely hope the chances of disaster are infinitesimally small and that most all modern supplies have adequate protection built in to avoid anything catastrophic. My concern is for the people playing around modified industrial or hobby grade equipment who don't understand the physics involved and that their actions may be potentially dangerous.

10) Using two power supplies for higher voltage/capacity chargers: safety issues
See post 183 in particular for conclusions.

An alternative approach that is intrinsically safer

11) And here is discussion of an alternative approach which floats the OUTPUTS rather than modify the inputs.
It has developed into a nice solution with a kit of parts available to make a twin 24V 47A system. Thanks akshu

racerxky has photos of how to isolate the OUTPUT of my original HP PROLIANT DL580/ML570G3 (12V 1300Watt) supply in Post #2 above here:

Here's a thread on using two Dell PE6800 supplies - they are the JD200 model

This is an intrinsically safer solution but does require significant disassembly and work on the supply. You can use the opportunity to add a resistor to the fans though and quieten them down a bit!
Last edited by jj604; Oct 28, 2015 at 03:51 PM.
Sign up now
to remove ads between posts
Aug 15, 2010, 08:18 PM
ancora imparo
jj604's Avatar
Thread OP

Reserved for updates and additions

I'll move the URL's from stuff that people add or more that I find into this post for easy reference from time to time. Only the stuff that isn't already on this first page so check the first 10 posts at least.

UPDATE: This thread is staying pretty focussed and to the point (thanks guys) so it is no big hassle to scan right through it. I won't move any more posts into this one for now.

1) Compaq Model DPS-450BB ( Delta Model number DPS-450BP)
Series ESP104
P/N: 401401-001
Spare/N: 101902-001

2) Some additional info on the ground pins on the = HP Power Supply DPS-600PB

3) Someone posted a useful link on the 100A supply thread.

It is an article, Modifying Hewlett Packard Server Power Supplies for Ham Radio Use which documents the modification of 2 types of Hewlett Packard switching power supplies to enable
their use as power sources for ham radio equipment. The article is intended to provide experimenters with the information necessary to modify successfully the following
types of power supply:
Hewlett Packard HP-194989 (400W, 32A max. on the 12v line)
Hewlett Packard HP-280127 (325W, 26A max. on the 12v line)

It contains some useful info on figuring out how to make them operate logically rather than by trial and error.
UPDATE: The link above no longer works but I have added the 3 page article to this post.
UPDATE: Here is a link which does work
Thanks wbefield.

4) Dell NPS-730AB 12V 60A supply

4) HP/Compaq Proliant DL380 G4 575w Power Supply, 406393-001
Series ESP135 Model No PS-3601-1C GPN:367238-501 PartNo:366982-501 Spares No:406393-001

5) TJinTech has a "how to" on the HP model DPS-600PB series ESP135 PS and also using two to get 24V with detailed instructions on his web site at

6) Dell Server PSU - Model NPS330BB A

7) How To for Dell NPS-730AB A REV A01
taken from Dell Power Edge 2600
max 13,5 Volt 60 Amps

8) Dell PowerEdge 2850 power supply, 12V 57A (700W)
Model #: Dell NPS-700AB

9) HP ESP-115 (30 amps)

10) Fujitsu-Siemens Primepower 450 server ps

11) Dell 7000814-0000 700W PSU

12) Hp PS3381-1C1 PSU

13) HP 511777-001 460W 12V PSU

14) Dell ASTN 7000245 Poweredge 6650 PS for 72 amps at 12v.

15) Esp 108 (DPS-450cb) PSU full pinout

Original post at

16) Dell Poweredge 6650(7000245) PS - Voltage Adjust

17) Dell Power Edge 4600 Server PS
See two posts 601 and 602 here

18) Dell DPS-500CB A

19) Delta DPS800GB-A
Posts 880 and 881
Last edited by jj604; Apr 20, 2012 at 02:39 AM. Reason: Updated with comment
Old Sep 28, 2010, 03:08 PM
A moderator felt this post violated the following rule: Off Topic Advertisement. It is temporarily hidden while lmlisak edits it.
Dec 29, 2010, 06:01 AM
ancora imparo
jj604's Avatar
Thread OP

People looking for info on particular supplies

Don't forget to post back a link when you get it to work.

Then I can delete it from here.
Last edited by jj604; Apr 20, 2012 at 02:33 AM. Reason: deleted old requests
Feb 15, 2011, 10:40 PM
TJin(Guy + Tech)
tjinguy's Avatar
I have added the Dell model AA23300 550W unit to my page.

It has the same hot-swap connector wiring as the NPS-700AB, which is also on the page.
Feb 20, 2011, 07:53 PM
Dale Kramer
KiloOne's Avatar

NPS-700AB Dell 2850 fan switch

I think the below picture shows how to add a fan switch to go from 'JET' speed to 'OK' speed.
Last edited by KiloOne; Feb 20, 2011 at 08:01 PM. Reason: Removed pic
Feb 21, 2011, 07:08 PM
Dale Kramer
KiloOne's Avatar

Automatic fan speed solution for DELL 2850 series
Apr 12, 2011, 08:26 PM
ancora imparo
jj604's Avatar
Thread OP

Some big ones

Poweredge 6800 Full Pinout DPS-1570AB
Poweredge 6850 Full Pinout
Poweredge R900 Full Pinout Posts 548 - 550

These are fairly large 120-140A supplies (some only work on 220V) with adjustable output voltage to 13.8 - 14V with NO FANS so they are quiet.

xandrios is posting some great info on supplies in the thread

A simple high quality 12Volt 100Amp Power Supply- Part1
(use the link above).
Apr 22, 2011, 07:58 AM
xandrios's Avatar

DPS-600pb ESP135 PSU voltage and fan control.
Last edited by xandrios; Jan 30, 2012 at 02:42 PM.
May 02, 2011, 04:49 AM
ancora imparo
jj604's Avatar
Thread OP

IBM Bladecenter 39Y7352 2000w PSU DPS-200BB A Pinout

Pinout for the IBM Bladecenter 39Y7352 2000w 200v-240v only PS.
All of the important pins are included.
Maximum output current is 164A at 12.2v. Voltage is adjustable up to 14.6v.
Since this PS doesn't have an internal fan, you MUST mount one externally.


xandrios advises "It seems that only revisions S8M and lower go to 14.6v.

Higher revision numbers can only reach 13v."
Last edited by jj604; Oct 04, 2011 at 06:09 PM.
May 15, 2011, 03:50 AM
ancora imparo
jj604's Avatar
Thread OP

More from xandrios

ColdWatt 650w CWA2-0650-IT01 and Intel SR1550 PS Full Pinout
Full Pinout for Delta DPS-830AB PS.
Full Pinout for Delta DPS-650QB PS.
Dell Poweredge T710 R910 PS Full Pinout
DPS-500EB PS Full Pinout
Delta DPS-750EB PS Full Pinout
Delta DPS-450GB Full Pinout
Delta DPS-850FB PS Full Pinout
Delta DPS-730AB PS Full Pinout
Delta DPS-350PB Full Pinout

Posts 679-710 here

Delta DPS-520BB Full Pinout. Post 730
Delta DPS-600DB Full Pinout. Same as Delta DPS-450CB. Post 729

Full Pinouts for several 3Y Server PSUs.
Pinouts for 3Y YM-2102ABR/AAR, YM-2102BBR, YM-2721ABR, YM-2821ABR, YM-2651BAR/CAR/CBR and YM-2451DAR/DBR PSUs.
Post 899
Last edited by jj604; Aug 28, 2011 at 05:16 PM. Reason: xandrios keeps adding new supplies!
Jul 22, 2011, 08:28 AM
Registered User
DonA's Avatar
See post #365 for information on increasing the voltage output of the Compaq HP DL580 Proliant Server Power.

Jul 30, 2011, 03:36 PM
xandrios's Avatar

OVP disable and Fan speed control modifications for several power supplies

Delta DPS-700EB PS OVP disable modification.

Poweredge 6800 KD175 PS OVP Disable modification

Poweredge 6800 PSU KD175 Fan Speed Control mod

Poweredge 6800 JD200 PS OVP Disable modification

Poweredge 6800 PSU JD200 Fan Speed Control mod
Last edited by xandrios; Jan 31, 2012 at 05:33 PM.
Aug 08, 2011, 10:02 PM
ancora imparo
jj604's Avatar
Thread OP

A neat case solution for twin supplies

Slightly OT but here's a solution I thought was very neat for people building twin 24V supplies. A lot simpler and quicker than starting from scratch.
Aug 21, 2011, 01:14 PM
Registered User
HP fanless units.
All these versions have the same connection layout.
ESP128, 280127-001, 305447-001, 26 Amp (325W)
DPS-460BB B, 361392-001, 325718-001, 36 Amp
DPS-525EB A, 389997-001, 384232-001, 42 Amp

It is difficult to effectively cool them, if anyone is looking here for list of "known" PS, i would recommend something with integrated fans.
These might be good if the plan is to build them inside a custom case.

Quick Reply

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
How to make own Power supply at home? convert from PC power supply? HumbleBoss Batteries and Chargers 16 May 01, 2016 02:13 PM
Discussion Convert Server Power Supply mt_100 DIY Electronics 28 Aug 19, 2010 01:03 PM
Discussion Help how to convert to Electric PT-20 Great Planes anteka Glow to Electric Conversions 1 Jul 25, 2010 11:07 AM