[Al Skierkiewicz]

7-11,
Under certain conditions the answer is yes. Those conditions are that the power supply returns go back to the common point on the breaker panel or to a common point on the Rockwell block. If you tie several returns together to a common wire (sized appropriately) and that then goes back to one of the common points, that is acceptable as long as it is insulated.
I don't always know what someone has in mind when they ask a question like this. You may not tie the common point to the robot frame/chassis as is common practice for auto electricals.