I THINK, his original question had to do with no GEC in the conduit that would bond/ground the frame of the transformer?
This is terminology that I don't normally use, so I'm going to try to sort it out. GEC is grounding electrode conductor, I believe. This is the conductor from the grounding rod or whatever, to the service that provides actual grounding (as opposed to bonding). The EGC is the equipment grounding conductor which is the actual bonding conductor that you run with the current-carrying conductors in the conduit or whatever for bonding devices and other equipment.
So, if this transformer is missing a GEC then that would mean that there is no conductor connecting the case of the transformer to a ground (like a metal column or cast iron water line or whatever).
Assuming the above is correct, then I'm totally okay with not having a GEC, because there is an EGC and that should be sufficient, and it means you don't have multiple grounds on the same service (which in the Canuck code we have specific rules against because of ground loops and stuff). Now, there certainly ARE exceptions where worries about static are more important than ground loops, so when wiring gas stations and whatnot you ground every frickin' thing you can find and to hell with ground loops, but in this case, not having looked up the chapter on wiring operating theatres in many years, but remembering vaguely that it at least used to say that in patient care areas an isolated system must not be grounded except through the sensing apparatus, I'm going to say with some certainty that adding a
ground to the case of the transformer would be specifically against code here in Canada, at least. This is a specific rule for this specific circumstance (isolated system in a patient care area) and not a rule relating to transformers in general.
