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Re: [Phys-l] home wiring catastrophe



Our general contractor, while inspecting the basement (small root cellar), noticed the plumbers had not inserted an insulator fitting between the galvanized to copper connection when they installed our water softener. So we hired him to re"wire" most of the plumbing. For all the cold he used PEX, and pointed out the resulting lack of a good ground. He used an electric hammer to drive a huge Cu rod into the ground near the switch box.
bc, pleased w/ our very general contractor (painted our house, subbed the gutters, and re stuccoed a damaged wall, inter alia.

Jeffrey Schnick wrote:

Thanks Carl for introducing a real-world physics topic and thanks John
for the excellent analysis. It would seem that beyond severing the
neutral line, two other things have to be/go wrong for the result to be


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the center tap is grounded--I would guess that it is connected to the
transformer case which is grounded separately from the neutral wire.
The neutral bus in the home is or should be grounded as well. In my
home the neutral bus is grounded by means of (what I estimate to be) an
8-gauge metal-clad copper wire clamped to the water main a few inches
above where the copper water main disappears into the ground. If the
grounding is ideal on both ends, and the neutral wire (but not the
ground connection) is cut near the transformer, the earth would play the
role of the neutral wire. I wonder if the neutral bus was properly
grounded in each of the homes.

Jeff Schnick


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