>> Instead, I think it's more likely that the difference in DC voltage can vary significantly. > >Why do you think this? Because as per the linked article, the

>> Instead, I think it's more likely that the difference in DC voltage can vary significantly. > >Why do you think this? Because as per the linked article, the absolute voltage potential of the earth in a local area can vary significantly over time. This make me think that the difference between a small isolated system and the earth ground must vary significantly. As you point out, everything actually is coupled, there is a time constant involved, but at least immediately after a nearby lightning strike you should have a significant difference. Because of the small capacitance of the isolated system, I'd expect you might see a high initial value that would soon (scale depending on the meter and the capacitance) decay to zero. Do you disagree? > House wiring is not limited in how much current it can put through you Absolutely agreed. Per the article, I'm referring to the supposed safety of an isolated transformer used a "razors only" outlet. In addition to having an intentionally small transformer, this system also has an intentionally very small fuse. > The reason why touching one wire is “safe” is because the return path for the current is usually very high resistance Yes. I guess the part that I'm failing to make clear is that I'm asking about the articles differentiation between isolated transformers and US standard circuits. In both cases, in normal dry clothed circumstances, there is normally a high resistance to any return circuit through your body. I'm still having trouble seeing the difference between the safety of the isolated system and the standard system. Most of the answers here (including yours) would seem to apply equally to both cases. I feel I understand this, just not the way in which the article explains the safety of isolated transformers.