Running a pump between two PSUs

CameronAsciak · January 1, 2015

Hi all

I’ve brought a cooler master HAF stacker and will have my main PC in the top, watercooling equipment in the middle ITX case and below that, I will have a mini server. Both my pc and my server will be connected in one big watercooling loop, using one pump to push all the water round. Now either just the PC or just the server may be on at one time but most of the time, they will both be running at the same time. The problem I’ve come up with though is to do with the way I could power the pump as i’m now not completely sure my original idea may work so that’s why I’m here. As the pump needs to be able to run when either the server or the main PC is on, it needs to be connected to both power supplies. My idea was to take a molex from each PSU and run a cable from them each to a single 3 pin connector (connected in parallel) which the pump can then be connected to. As they are in parallel, then when either PSUs are on, the pump will run but when they are both on, the voltage will be the same so the pump wont be damaged. My question however is this; is it safe/will it work to connects two PSUs in this way? I thought it would be ok as they will only be joined in parallel.

Many thanks, and a happy new year

Cameron

PS i've included a basic MS Paint drawing to help illustrate what I mean