Using 6 pin PCIE from Server PSU

Mostly Printed CNC - MPCNC Troubleshooting
1

Hello,
Would using a 6 pin PCIE from a Server PSU work to power BTT SKR Pro V1.2? It would seem to work, but I’d like to ask about this before-hand.

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How would this be wired? I’m still in the process of building it, and I think it would be interesting to run it though these.
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Thank you very much

2

I don’t know anything about a server PSU. But I have done this with regilar ATX power supplies. The challenges are:

  1. You need to turn it on. At least with atx supplies, there is a wire you have to pull to ground to make it turn on. Maybe the aerver ones are alway on?
  2. Some power supplies expect a significant load. They turn off if there isn’t much load. Our cnc machines seem like big tough things, but when the motors aren’t enabled, they sip power (ny comouter standards). So sometimes that can be fickle.

Otherwise, it looks like you have 12V DC and ground, so you can just wire those up. If a single 12V pair can’t handle the current of the machine, you might get away with wiring two or three pairs together.

3

I just solder wires to the big terminals on the server psu and solder a wire with a switch to the pads that turn the psu on. I even have a couple of server psu’s with screwterminals soldered to the psu terminals. Just drilled a wire trough them en soldered them. Works fine to me.

I even powered my drone with one. Had to try something while the batteries were dead. About 30 amps at 12V works fine.

4

It all depends on which server PSU you have. Some will require small modifications to work and some work straight off the bat. There are many you tube tutorials on a myriad of different PSU’s, I suggest you check them out for your specific PSU. A server power supply is a much higher quality PSU than an ATX PSU, being both more stable, more reliable and less noisy, commensurate with the repercussions of one failing!
I have a DELL 7000B14-0000 and a HPDPS-600PB currently ‘in service’.

As you have the ‘add-on’ board at the rear of your PSU it ‘should’ work straight away as the board will most likely provide the (sometimes) required ‘enable’ signal and fan control signals.

It looks from the picture there are only 6 pin connectors on that board so take your +12V and ground …simple!

These PSU’s are a bit of overkill for a CNC, being capable of supplying around 50 - 60 amps@12V

5

It looks like the breakout board has a power switch too. So I agree, it looks like it will be fine, and probably overkill.

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