2 Different power supplies: Connecting V- together

[Noise]

Hi everybody,

I have a rack where there are two different power supplies. I would like to avoid gnd loops, or dangerous short circuits. Is it safe to tie all '-' terminals together? If so, should I connect the earth terminals, which are already connected to the rack chassis, to the common '-'?

Thanks

 

[Tha fios agaibh]

It sounds fine to me. You can either tie all your "-" (negatives) to earth ground, or just tie the two together and have a floating neg rail.
As long as your grounds are tied together at the source only you won't have ground loops.