Good afternoon all:
The whole concept of eliminating strong paths to ground seems like it would be very limited in it's effect, just because of the scope of the project: Not only would all plumbing have to be insulated, but the proximity to any concrete (especially reenforced) would be a concern; the proximity to the service equipment and GE would be a concern; every house would have to be built to incredibly stringent standards and even then it seems like there is a lot of room for error.
I once recieved a bad shock while standing on the wooden floor on the third story of a wood frame house. I'm sure the EGCs and plumbing did their part to conduct the fault current, but obviously the wood itself had to be significantly conductive to even allow the fault current to get to the EGCs and pipes.
Unless what I experienced was somehow a special circumstance, it leads me to believe that in wood-frame houses, if you were standing near a foundation wall or there was no basement, you would be at significant risk for a severe shock regardless of whether there was an EGC or copper piping somewhere near-by: The conductivity of the materials used in the house is sufficient enough to allow dangerous current levels to pass.
People ask me if it's safe to shower during a lightning storm if their bath-tubs are fiberglass. My default response is: "If it wasn't designed with electrical insulation in mind, you can't expect it to preform in that capacity."
Is that really that far off base?
-John
