Can anyone inform me as to what limitations the code places on using building steel columns as a grounding means? Is it safe to assume in an industrial environment where coulums sprout up in many places that a 480v branch circuit can come out of conduit to rails on a overhead crane without an EGC? And that because "all of this steel is up there" ,it will protect exposed wires in case of a ground fault? The circuit comes from a 60 disconnect fed off a busway feeder. Thanks in advance for your anticipated help>