If you have a grounded outlet, it MUST be tied to ground.
Is it required or can it be kept isolated from the control panel circuit?
Why are you designing a control panel with two separate voltage sources?
If both grounds are earth, and you tie both grounds to earth, then both grounds are referenced to the same potential.
What's wrong with having two separate sources in a panel? Is it dangerous? I would say if all wires are labeled properly, then what's the issue with it?
Actually there is a potential voltage difference between 2 earth ground points.
As soon as they (not 'he') looked at the setup, they stated that the machine was grounded to the ground rod for the press, in front of the machine. But, the feeder control panel, on the back of the machine, had its own ground rod that the servo controller was tied to.