I have been away from the IT biz for a while but we never brought a "neutral" to the computer room panels. The center point of a wye was still grounded at the service disconnect. I suspect there may be some people who misunderstand what that advice really means tho. "Isolated Ground" is also misunderstood. In our planning manuals, they suggested that the wire that would be the neutral be used for the isolated ground but it is still solidly connected to the grounding point in the service disconnect where the main bonding jumper lands. The only thing that makes it "isolated" is it does not connect to buildiing steel or any other grounded point after it leaves the service disconnect enclosure. It only connected to the machine frames.The equipment grounding conductor is still run normally. There end up being so many other unintentional grounding paths that this is really more theory than fact. IBM abandoned the isolated ground recommendation back in the 70s but some misunderstanding won't go away.
I have argued with installers who think "isolated Ground" means a separate grounding electrode system and that will actually cause more problems that it fixes.
