I had a situation similar to this at a campground that was traced back to an older rig plugged into a 30 amp circuit. When he switched to his 50 amp cord and plugged into the same pedestal 50 amp circuit the problem went away.
Maybe each pedestal should have its own earth ground post, used only as a sensor, and a red light indicating a voltage difference (above a threshold) between its local earth ground and its EGC connection. Actually, each RV should probably have this too, in some form.
I had a situation similar to this at a campground that was traced back to an older rig plugged into a 30 amp circuit. When he switched to his 50 amp cord and plugged into the same pedestal 50 amp circuit the problem went away.
There have been deaths resulting from this condition at marinas.
Maybe each pedestal should have its own earth ground post, used only as a sensor, and a red light indicating a voltage difference (above a threshold) between its local earth ground and its EGC connection. Actually, each RV should probably have this too, in some form.
That would work, but I don’t see campgrounds spending money on that. But I do have a few ideas. Please stand by…
I suppose a person holding a NCVT could check the pedestal housing and/or its ground contacts?