The NEC lists four means of alteration to a grounding system when the use of multiple grounding connections results in objectionable current [250.6(B)].
1. Disconnect one or more (but not all) of the grounding connections.
2. Change the locations of the grounding connections.
3. Interrupt the continuity of the conductive path causing the objectionable current.
4. Do something else (it just has to be approved).
What might that “something else” be? You could, for example, bond two grounding connections together with a bonding jumper. This puts them at the same potential; thus, no current can flow between them.
That “something else” can’t include something unapproved such as operating electronic equipment on a branch circuit that’s not connected to the equipment grounding conductor (EGC) [250.6(D)]. Many times, “isolated ground” (IG) is installed with this idea in mind but that’s not what’s meant by IG. See IEEE-142 (the Green Book) for a detailed discussion of the IG method.
Something abnormal such as temporary current resulting from a ground fault is certainly objectionable, but it doesn’t fall under the NEC definition of “objectionable current” [250.6(C)].
