Paul,
The following was primarily pertaining to your last post. It may also be relevant here.

Very interesting. Sorry I missed out on the guessing. Just a couple questions or comments: Is it not true, that 100mA is enough to kill you? If so, who decided to set your GFCI protection at 100mA? What is the purpose? It sounds like a good idea to protect the entire house and it would be easy to do with your straight 240V system, but does that mean every time an element burns out, the entire house loses power or are there lower rated, faster acting GFCIs on some of the branch circuits? Comes to mind because, when I worked at a production plant once, we had material dryers that would lose an element ever now and again. It would take out half the floor. Had to turn the settings so high. What was the sense in having the GFCI protection? I did work with the engineers to solve the heater element failure problem but my point is that not every Ground Fault is a potential danger to human life. Sometimes we need to separate the life threatening protection and the simple over-current protection. How do you handle that? Oh yes, one other thing, for those of you who had noticed my “stolen tools” post, I had a wonderful tracer kit that would have brought you to that short in about five minutes. Sorry, had to B#!@%&#! Do you have a separate grounding path? Is one leg a “neutral” or a grounded leg? If you don’t have an effective grounding path how do you clear faults? Is it done with GFCI? That may not work all the time. I could go on. Obviously, I’ve never been there. My curiosity has risen.
God bless,
Dan