Well Reno— I don't profess to being an expert on hospital wiring or anywhere near what some people are who actually install the systems. I do know that the code panels have wrestled with the bonding/grounding wording for some time and will continue. The 2011 code eliminated the term "grounding conductor" as an example of the confusion. I do believe the goal in 517 is to "Bond" the grounding bus' together to eliminate any difference between them. The analogy that Greg offered is valid and I will have to agree that it seems overkill for the requirement in 517 to have to run a seemingly redundant #10 wire between grounding bus' but that's what it says.
