The Cyndustries List

So today I was using my Modcan/Cynthia system and cross patching with my Driscoll/Serge system and ran into some grounding issues.

The Modcan/Cynthia rig is powered with a Cynthia Major PSU and the Serge/Driscoll rig is powered with a power-one supply I got from ebay and wired up myself.

On the PSU I wired, I took the signal ground to my ground jack to use when connecting to other PSU's.  Upon examining the Major PSU I found that the grounding jack is connected to the PSU chassis and the earth ground.

After discovering this I remembered I had a Serge PS6 in my closet so I opened it up and the ground jack is indeed connected to the signal ground.

I'm wondering if this is how the Cynthia PSU is supposed to be wired?  I can't figure out how it makes sense to wire it that way.

Anyone have an explanation?

epk