DIYbanter - View Single Post

Dave Martindale

(Doug Miller) writes:

Rain water is actually close to distilled water, which is a very poor
conductor. Pure enough water can be treated as an insulator.

While true, this is not really relevant, as water is never found in the pure
state in nature.

Not absolutely pure, but the degree of impurity determines its
conductivity (more or less). The water molecules themselves don't
conduct worth a darn, but other substances dissolved in it can increase
conductance greatly. Well water usually has high dissolved solids,
while rain water has almost none, and lake water tends to be somewhere
in between. In this case, if the lake rose tens of feet in a short
time due to rain, the water was likely less conductive than usual.

In addition, there was likely less than a square inch of "hot" conductor
exposed to the water, and current flow across this interface will be
proportional to area.

Dave