Wire ATX Power Supply Busbar for Atom CPU Farm (12V 256A total)
Hello
I am new here and as you can probably tell very soon, I don't have a lot of experience in electronics. I am a programmer with some basic electronics understanding. To make matters worse, English is not my native language so please be gentle (I am in Asia but I was born in Europe)
For a small project I have been using PC Power Supplies (ATX PSUs) to power 16 small low-cost Atom mainboards (they are basically small noname mainboards with an Intel Atom CPU and everything on board, such as display card, wifi, etc). They use 12V power inputs and have a low power consumption (around 40W continues).
Scroll down for a photo of these Atom boards (I am not using these, but you get the picture).
The ATX PSU I have been using has a single 12V rail that can provide up to 816W/68A with a very good efficiency (Cooler Master M2 Silent Pro 850W is the type). I am actually only using around 640W (16 Atoms * 40W), but to have a safety buffer and for the easy of calculation, I would like to assume we are talking about 4A per Atom Board (48W).
What I did so far is wiring 16 wires of 16AWG from the +12V output pins of the power supply to the 16 different Atom Boards. Same for the GND pins. I've been using this setup for a few weeks now, it works fine and looks professional.
But now I have to increase the no. of Atom PCs to 64 in total, so I will need 4 PSU's in total. To make matters worse, I have some space constraints so I can't wire one by one. I will have to go to a busbar outside the case, then have a +12V and GND wire in 8AWG go into a case, and then go to another busbar for power distribution again.
And this part is exactly where I hope to get help here. We are talking about a lot of Ampere and really fat cables for my taste, so I just want to double check what I am doing won't burn the house down and I don't kill myself in the process.
So what I want to do is (once for +12V and once for GND):
Repeat for GND.
So after I am done I will have one ATX PSU that powers 16 Atoms again.
On the PSU side I have 2 busbars, one for 12V one for GND.
The two 8AWG wires go through a cable conduit.
On the farm side I will have 2 more busbars.
Then I have the 16 pairs of 12V and GND again to the Atom PCs.
Here are my questions:
I will have 4 of these setups, independent from each other. But the fat ~8AWG (~10mm²) wires (4x 12V and 4x GND) will run in the same conduit into the case. Is this a problem?
While I initially used to connect 16 wires to the PSU, my busbars don't have 16 holes. I am using 16AWG wires and the sockets on the PSU are rated high enough. How many 16AWG wires in parallel would you run from the PSU to the busbar?
I am planning to use bootlace ferrules and heat-shrink tubing on the 8AWG wires and screw them down to the bus bars real good. Is this "good enough" even for the 64A current on them?
Anything else I should consider when I am doing all this? (except getting life insurance, being extra careful, and having somebody double check my work)
Here are the pictures:
Here is what I wired up so far (busbar rated 128A):
Hello
I am new here and as you can probably tell very soon, I don't have a lot of experience in electronics. I am a programmer with some basic electronics understanding. To make matters worse, English is not my native language so please be gentle (I am in Asia but I was born in Europe)
For a small project I have been using PC Power Supplies (ATX PSUs) to power 16 small low-cost Atom mainboards (they are basically small noname mainboards with an Intel Atom CPU and everything on board, such as display card, wifi, etc). They use 12V power inputs and have a low power consumption (around 40W continues).
Scroll down for a photo of these Atom boards (I am not using these, but you get the picture).
The ATX PSU I have been using has a single 12V rail that can provide up to 816W/68A with a very good efficiency (Cooler Master M2 Silent Pro 850W is the type). I am actually only using around 640W (16 Atoms * 40W), but to have a safety buffer and for the easy of calculation, I would like to assume we are talking about 4A per Atom Board (48W).
What I did so far is wiring 16 wires of 16AWG from the +12V output pins of the power supply to the 16 different Atom Boards. Same for the GND pins. I've been using this setup for a few weeks now, it works fine and looks professional.
But now I have to increase the no. of Atom PCs to 64 in total, so I will need 4 PSU's in total. To make matters worse, I have some space constraints so I can't wire one by one. I will have to go to a busbar outside the case, then have a +12V and GND wire in 8AWG go into a case, and then go to another busbar for power distribution again.
And this part is exactly where I hope to get help here. We are talking about a lot of Ampere and really fat cables for my taste, so I just want to double check what I am doing won't burn the house down and I don't kill myself in the process.
So what I want to do is (once for +12V and once for GND):
Code:
[ATX PSU]
IIIIIIII (+12V 8 wires of 16AWG? enough?)
(1 foot)
IIIIIIII
[BUS BAR]
I (+12V 1 wire 8AWG in conduit)
(3 foot long)
I
[BUS BAR]
IIIIIIIIIIIIIIII (+12V 16 wires 16AWG)
(1 foot)
IIIIIIIIIIIIIIII
[16x Atom]
So after I am done I will have one ATX PSU that powers 16 Atoms again.
On the PSU side I have 2 busbars, one for 12V one for GND.
The two 8AWG wires go through a cable conduit.
On the farm side I will have 2 more busbars.
Then I have the 16 pairs of 12V and GND again to the Atom PCs.
Here are my questions:
I will have 4 of these setups, independent from each other. But the fat ~8AWG (~10mm²) wires (4x 12V and 4x GND) will run in the same conduit into the case. Is this a problem?
While I initially used to connect 16 wires to the PSU, my busbars don't have 16 holes. I am using 16AWG wires and the sockets on the PSU are rated high enough. How many 16AWG wires in parallel would you run from the PSU to the busbar?
I am planning to use bootlace ferrules and heat-shrink tubing on the 8AWG wires and screw them down to the bus bars real good. Is this "good enough" even for the 64A current on them?
Anything else I should consider when I am doing all this? (except getting life insurance, being extra careful, and having somebody double check my work)
Here are the pictures:
Here is what I wired up so far (busbar rated 128A):
Last edited: