I just wanted to throw this out there and see what everybody thinks about this situation. At the facility I work at, everything is fed from six, 1000KVA, 480v secondary transformers, through switchgear, and then routed out to tap boxes located throughout the facility. From the tap boxes it either runs to 200A three phase load centers or down to lighting panels. This is where it gets interesting. There is not a neutral in this facility. All the 277V lighting is utilized by one leg of the 3 phase and the ground. In each ArmourFlex cable coming to the lighting panels there are three sets of bare ground wires that terminate in the lighting panel. I vaugly remember in school something about a "CN" system or something like that, but thats been 30 years ago. Anybody ever see this type of grounding/neutal set-up before.