I have an outbuilding with a subpanel. I realized that the subpanel was wired to use the same bus bar for ground and neutral, which I understand is not the correct way to do things, and I'd like to fix it if that's possible.
In the diagrams I've seen, the subpanel's ground bus will connect to a grounding electrode and also to a ground wire leading back to the main panel. Unfortunately the cable to the outbuilding does not have a ground wire, nor metal conduit, and I am unable to run new cable between the panels.
My options are to leave things as-is, with bonded neutral and ground in the subpanel, or to separate the neutral and ground at the subpanel and rely on the grounding electrode for the outbuilding's ground. I know neither of these options are ideal, but is one of these preferable over the other?