Mounting a PSU in a separate case

toronado455 · Post by **toronado455** » Tue Feb 26, 2008 10:07 pm

Is there any *electrical* reason the PSU needs to be mounted in the same case as the rest of the system?

Just thought I'd ask before I do this in case I'm overlooking something obvious.

xan_user · Post by **xan_user** » Tue Feb 26, 2008 10:22 pm

Not that i've found.....

.....yet

toronado455 · Post by **toronado455** » Tue Feb 26, 2008 11:03 pm

So I take it you've done this?

Just to elaborate a little on my reason for doing this... I need more space above the MB. I'm putting in a larger HSF and the CPU socket on this particular MB is right up against the top edge of the MB. Plus, I'd like to give the PSU its own air space to see if it will run cooler and quieter.

The *real* solution would be a P180. But I happen to have an extra case sitting around not doing anything and the system in question is older and isn't even worth the cost of a P180.

Redzo · Post by **Redzo** » Tue Feb 26, 2008 11:25 pm

In that case why just not have PSU outside, behind the case and route in cables thru PCI slots.
It does not get any cooler then that. Of course pets and such could be a problem though

And it would look a lot "cleaner" then 2 boxes beside/on each other IMHO.

xan_user · Post by **xan_user** » Wed Feb 27, 2008 12:11 am

Poormans p182 = PSU and HDD in one case, Mobo and optical drives in other.

Of course there was the time I had two complete p4's (prescott and a northwood) in one regular AT case. I think my ears are still ringing from that one!

Bluefront · Post by **Bluefront** » Wed Feb 27, 2008 4:25 am

I hung my fanless Zen on the rear outside of the case. And ran the wires through a hole in the panel. This way the main PSU cable can be very short, with most of it outside the case. The Zen works fine with just convection cooling....no problems after six months or so.

FlorisNielssen · Post by **FlorisNielssen** » Wed Feb 27, 2008 7:17 am

Only problem could be grounding.
In the PSU, the ground-cable from your power point is mounted (with a screw) to your PSU-case. The PSU-case is mounted to the case, and the case is fully grounded. But if you put the PSU outside the case, the main case won't be grounded. Most of the time this isn't a problem though.

toronado455 · Post by **toronado455** » Wed Feb 27, 2008 9:46 pm

FlorisNielssen wrote:Only problem could be grounding.
In the PSU, the ground-cable from your power point is mounted (with a screw) to your PSU-case. The PSU-case is mounted to the case, and the case is fully grounded. But if you put the PSU outside the case, the main case won't be grounded. Most of the time this isn't a problem though.

Well, you hit upon my main concern and my reason for asking this question. Grounding (or lack thereof) is the main issue I'm thinking about. So how do I know if I can do this safely?

Doesn't the PSU MB connector have some sort of ground wire in it so that when it connects to the MB it grounds the MB (and anything else connected to the PSU with the various connectors, fans, HDs, etc.)?

Also, the spare case I want to mount the PSU in is aluminum and the case with the rest of the system is steel. I don't know if that makes any difference grounding wise.

Bluefront · Post by **Bluefront** » Thu Feb 28, 2008 2:14 am

The MB is properly grounded when the PSU is plugged into it. The case itself can be a problem if the MB is not grounded properly to it. The solution is simple.....if you use screws to hold the MB to the tray, that should provide a necessary ground to the case. To be more certain.....run separate ground wires from the PSU case directly to the computer case.....the tray, the case body, the front bezel, etc.... The type of metal used at the ground point can be steel, aluminum, copper....no big difference.

The black wires in a molex connector from the PSU are ground wires.....they can be used to attach directly to the case.

xan_user · Post by **xan_user** » Thu Feb 28, 2008 9:13 am

Plenty of people run acrylic and wood cases without problems. In fact if there was a problem with an ungrounded mobo and psu then wouldn't acrylic case be more prone to problems due to static build up?

I'm not suggesting anyone run your system ungrounded. my cases are in effect screwed together, to form one double case.

The best part is i'm recycling two cases for one pc.

toronado455 · Post by **toronado455** » Thu Feb 28, 2008 11:56 am

xan_user wrote:Plenty of people run acrylic and wood cases without problems.

Excellent point. There are plenty of cases made from non-conductive materials that are working just fine.

xan_user wrote: In fact if there was a problem with an ungrounded mobo and psu then wouldn't acrylic case be more prone to problems due to static build up?

That's an excellent question. I hope someone has an answer to that one.

xan_user wrote: I'm not suggesting anyone run your system ungrounded. my cases are in effect screwed together, to form one double case.

Perhaps the rule should be that if you are running a case made from a conductive material like steel, then such a case should be properly grounded? (Just a guess.)

My idea at the moment is to run a wire from one of the four standard PSU mounting screws in the PC case that I'm using just for the PSU over to one of the unused PSU mounting screws in the main system case. I believe that would provide a direct ground connection from the point where the PSU would normally be mounted in the main system case to the point at which the PSU is now "remotely" mounted.